tag:theconversation.com,2011:/id/topics/human-genetics-6486/articlesHuman genetics – The Conversation2023-08-22T21:54:17Ztag:theconversation.com,2011:article/1847232023-08-22T21:54:17Z2023-08-22T21:54:17ZNew research into genetic mutations may pave the way for more effective gene therapies<figure><img src="https://images.theconversation.com/files/543314/original/file-20230817-8328-bdaz8a.jpg?ixlib=rb-1.1.0&rect=44%2C0%2C5000%2C3315&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A lab dish containing embryos that have been injected with Cas9 protein and PCSK9 sgRNA is seen in a laboratory in Shenzhen in southern China's Guangdong province.</span> <span class="attribution"><span class="source">(AP Photo/Mark Schiefelbein)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/new-research-into-genetic-mutations-may-pave-the-way-for-more-effective-gene-therapies" width="100%" height="400"></iframe>
<p>Consider a living cell, which can have thousands of genes. Now think of these genes as dials that can be tweaked to change how the cell grows in a given environment. Tweaking a gene can either increase or decrease growth, and this is made more complex considering these dials are interconnected with each other, like cogs in a machine. </p>
<p>While scientists are now able to edit genes in laboratory conditions and attempt to produce findings that may lead to cures, evolution has been doing this for billions of years. Evolution is the natural process that turns these dials, allowing populations to adapt. However, unlike scientists, evolution turns these dials randomly as mutations affect the function of genes.</p>
<p>One underlying hypothesis in evolutionary theory — the evolutionary contingency hypothesis — has been that this tuning can have chaotic behaviours. Or, in other words, dials tweaked early in the process can dramatically alter later evolutionary potential.</p>
<p>Stephen Jay Gould was a famous proponent of this theory, arguing in his 1989 book <a href="https://wwnorton.com/books/9780393307009"><em>Wonderful Life</em></a> that since beneficial mutations occur randomly, chance must play an important role in evolutionary diversification.</p>
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<a href="https://theconversation.com/does-our-dna-really-determine-our-intelligence-and-health-199266">Does our DNA really determine our intelligence and health?</a>
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<p>If this hypothesis is true, it affects how scientists should edit genes in the laboratory as they will face the chaotic interconnections of our cells. Our work set out to test this hypothesis.</p>
<h2>Resolving an evolutionary paradox</h2>
<p>We can observe the process of evolution in the laboratory under extremely well-controlled conditions. We have done so by growing populations of micro-organisms for hundreds — <a href="https://doi.org/10.7554/eLife.63910">even thousands — of days</a>. </p>
<p>Since these organisms divide and reproduce so quickly, this process represents thousands of generations of growth. These experiments have allowed us to pinpoint <a href="https://doi.org/10.1038/s41586-019-1749-3">precisely when</a>, and how, beneficial mutations co-occur and compete to take over the population.</p>
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<img alt="Image of a human genome." src="https://images.theconversation.com/files/543310/original/file-20230817-41912-psfxhj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/543310/original/file-20230817-41912-psfxhj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/543310/original/file-20230817-41912-psfxhj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/543310/original/file-20230817-41912-psfxhj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/543310/original/file-20230817-41912-psfxhj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=525&fit=crop&dpr=1 754w, https://images.theconversation.com/files/543310/original/file-20230817-41912-psfxhj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=525&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/543310/original/file-20230817-41912-psfxhj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=525&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Image readout of a human genome.</span>
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<p>One striking observation from every single one of these experiments is that increases in fitness slow down over time at a rate that is surprisingly reproducible. Despite accumulating different mutations, different populations show remarkably predictable diminishing returns in how fast they adapt.</p>
<p>In contrast with the seemingly chaotic behaviour of mutations, fitness or growth changes are highly predictable. This has led many to hypothesize that this order of mutation is an <a href="https://doi.org/10.3389/fgene.2015.00099">inherent consequence</a> of the way biological systems have evolved. </p>
<p>This striking hypothesis is at odds with the idea that the <a href="https://doi.org/10.1038/s41559-020-01286-y">specifics of an organism’s biology matter for evolution</a>. In other words, it has been difficult to prove that the order in which evolution turns dials has any impact on the future.</p>
<h2>The answer to the paradox</h2>
<p>My team was able to show that the answer to resolving this paradox lies within the interconnected gene network of the cell itself. </p>
<p>For evolution to work, the dial-tuning must be precise: even if the net outcome is beneficial, adjusting one set of linked dials can trickle down and affect other previously correctly placed dials. As evolution continues, the probability of breaking harmoniously-tuned dials grows. This seemingly simple principle explains why the rate of evolutionary improvements typically slows down over time. </p>
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<img alt="A tray containing human DNA samples ready for genetic sequencing." src="https://images.theconversation.com/files/543312/original/file-20230817-23-a743da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/543312/original/file-20230817-23-a743da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=521&fit=crop&dpr=1 600w, https://images.theconversation.com/files/543312/original/file-20230817-23-a743da.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=521&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/543312/original/file-20230817-23-a743da.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=521&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/543312/original/file-20230817-23-a743da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=654&fit=crop&dpr=1 754w, https://images.theconversation.com/files/543312/original/file-20230817-23-a743da.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=654&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/543312/original/file-20230817-23-a743da.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=654&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A tray containing human DNA samples ready for genetic sequencing.</span>
<span class="attribution"><span class="source">(AP Photo/Patricia McDonnell)</span></span>
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<p>Resolving this paradox experimentally was not an easy task. After all, how can one show the entanglement of dials within the cell? <a href="https://doi.org/10.1126/science.abm4774">In our recent study</a>, we tackled this challenge by systematically trying out every possible combination of 10 key beneficial mutations and looking at how they affect the growth of cells.</p>
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Read more:
<a href="https://theconversation.com/human-genome-editing-offers-tantalizing-possibilities-but-without-clear-guidelines-many-ethical-questions-still-remain-200983">Human genome editing offers tantalizing possibilities – but without clear guidelines, many ethical questions still remain</a>
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<p>By testing out combinations of mutations, we were able to reliably understand which mutations were entangled together (this entanglement is known as epistasis) and for just 10 mutations, over 1,000 combinations had to be generated.</p>
<h2>How this affects genetic precision medicine</h2>
<p>Current futuristic technologies tout the ability to generate precise single mutations within our own genomes with the hope that this can be used to repair non-functional genetic variants. For example, <a href="https://doi.org/10.1038/s41586-019-1711-4">prime editing</a> is an effective “search-and-replace” genome editing technology.</p>
<p>One important concern with these approaches is they can introduce undesired mutations at the same time. However, even as scientists solve these concerns, the field of human genetics has often <a href="https://doi.org/10.1038/s41576-019-0127-1">overlooked the importance of the interconnectedness of genes</a>.</p>
<p>Our study demonstrates that bioengineers should think not only about the effect a mutation has on the gene it is in, but also about the effect of the mutation in the context of all other variations in our genomes. Altering the function of any of our genes can affect our interconnected cellular networks. </p>
<p>This is compounded by the fact that all of us carry hundreds of extremely rare variants, which means each of us carries a unique interconnected network of genes. These personalized networks make us who we are. </p>
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Read more:
<a href="https://theconversation.com/somatic-genome-editing-therapies-are-becoming-a-reality-but-debate-over-ethics-equitable-access-and-governance-continue-201234">Somatic genome editing therapies are becoming a reality – but debate over ethics, equitable access and governance continue</a>
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<p>Genome interpretation is at the heart of genetic testing for disease. And while scientists have made some progress in identifying key pathogenic genetic variants (those that can cause disease), our findings demonstrate that classifying a variant as pathogenic or benign requires us to also understand how the other genetic dials in our cells are tuned.</p><img src="https://counter.theconversation.com/content/184723/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alex Nguyen Ba receives funding from the Natural Sciences and Engineering Research Council of Canada. </span></em></p>New research sheds light on the interconnected nature of the human genome and what this means for future gene therapies.Alex Nguyen Ba, Assistant Professor, Biology, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2084162023-06-29T15:01:08Z2023-06-29T15:01:08ZResearchers can learn a lot with your genetic information, even when you skip survey questions – yesterday’s mode of informed consent doesn’t quite fit today’s biobank studies<figure><img src="https://images.theconversation.com/files/534693/original/file-20230628-29-j4a0gl.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1999%2C1499&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Participants in biobank studies are often asked for broad consent to use their data.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/genetic-research-royalty-free-image/136810911">Science Photo Library - TEK IMAGE/Brand X Pictures via Getty Images</a></span></figcaption></figure><p>Imagine you agreed to be part of a new and exciting long-term research study to better understand human health and behavior. For the past few years, you’ve been visiting a collection site where you fill out some questionnaires about your health and daily activities. Research assistants take your height, weight and some other physical characteristics about you. Because you agreed to contribute your genetic data to the study, you also provided a saliva sample during your first visit.</p>
<p>Later, you see a news article reporting that researchers analyzing data from the study you’re participating in have <a href="https://www.vox.com/science-and-health/2018/8/23/17527708/genetics-genome-sequencing-gwas-polygenic-risk-score">found genetic variants</a> that predict the likelihood of someone completing college. You remember reading a long form when you consented to giving your data, but you can’t quite remember all the details. You know the study was about health, but how do these findings about genes and education have anything to do with health? Did they analyze your data specifically? What did they find? </p>
<h2>What are biobanks?</h2>
<p>Many scientific research studies collect data meant to answer a specific research question. For example, to study the genetics of diabetes, researchers might collect data on your blood pressure and lipid levels in addition to genetic data. But increasingly, scientists are collecting large amounts of data to be <a href="https://doi.org/10.1186/s12967-019-1922-3">kept in biobanks</a> – repositories that store genetic data and other biospecimens like blood, urine or tumor tissue to be used in a wide number of future studies.</p>
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<figcaption><span class="caption">Biobank data is often used to conduct genome-wide association studies, or GWAS.</span></figcaption>
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<p>Some biobanks, like the <a href="https://www.ukbiobank.ac.uk">UK Biobank</a>, link biospecimen data to other collected data, such as sexual behavior, medical history, weight, diet and lifestyle. Private companies <a href="https://theconversation.com/how-a-south-african-communitys-request-for-its-genetic-data-raises-questions-about-ethical-and-equitable-research-166940">like 23andMe</a> also obtain consent from their customers to have their data used in research efforts.</p>
<p><a href="https://scholar.google.com/citations?user=zCedU50AAAAJ&hl=en&oi=ao">As a researcher</a> interested in the intersection between <a href="https://www.robbeewedow.com">social behaviors and genetics</a>, I frequently have conversations with people who weren’t aware of how their genetic data is being used. They’re often surprised that the genetic data they consented to be used for research at a private company by using a DNA testing kit or at a biobank while visiting their local clinic might be used to study the genetics of <a href="https://doi.org/10.1126/science.aat7693">same-sex sexual behavior</a> or <a href="https://doi.org/10.1038/s41588-018-0309-3">risk-taking</a>. </p>
<p>In our newly published research, my colleagues and I found that even <a href="https://www.nature.com/articles/s41562-023-01632-7">choosing not to respond to survey questions</a> can reveal information about the population (we found that not responding to survey questions is correlated with a person’s education, health and income levels) if genetic data is available.</p>
<h2>Genetic data and informed consent</h2>
<p>The research that can be done with biobank data might sound scary, but it shouldn’t be. Genetic data, like the data used in our study, is de-identified. This means that it cannot be linked back to individual research participants, who remain anonymous. Further, genetic data for these sorts of genetic studies is used <a href="https://doi.org/10.1038/s43586-021-00056-9">at the aggregate level</a>, meaning it isn’t used to predict or evaluate any one particular individual’s responses or behaviors.</p>
<p>Researchers aren’t using genetic data to target individuals with certain genetic profiles. Almost all genetic research is used to better understand how health behaviors and other factors affect health and to figure out ways to improve outcomes. This goal is why most research participants agree to contribute their data to research in the first place: to help the world through science.</p>
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<figcaption><span class="caption">Many developments in human subject protections arose in response to unethical research.</span></figcaption>
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<p>The problem is whether research participants really understand how their data can be used. Many of the original ideas around the development of the <a href="https://doi.org/10.1186/s12910-019-0414-6">informed consent process and Institutional Review Boards</a>, or IRBs, intended to protect research participants from direct harm or privacy violations were based on the expectation that research studies would be addressing particular questions about a single subject, like cardiovascular disease or lung cancer. This focus was so as not to repeat unethical research atrocities like the infamous <a href="https://www.cdc.gov/tuskegee/timeline.htm">Tuskegee Syphilis Study</a>, where researchers did not tell participants, who were all Black men, that they had syphilis and withheld treatment that was already widely available and known to be highly effective.</p>
<p>But since genetic data is de-identified, it is <a href="https://www.hhs.gov/ohrp/node/4350/index.html">often considered exempt from full IRB review</a>, which is a protocol to ensure studies meet ethical standards and institutional policies. And the broad number of research questions that can be explored with biobanks, along with the amount and types of data collected, has made these original protections to ensure truly informed consent insufficient.</p>
<h2>Improving informed consent</h2>
<p>To be clear, biobanks are enormously important for public health research. They allow researchers to <a href="https://theconversation.com/people-dont-mate-randomly-but-the-flawed-assumption-that-they-do-is-an-essential-part-of-many-studies-linking-genes-to-diseases-and-traits-194793">link many different outcomes and variables</a> together to paint a critical overall picture of human health and behavior. And in contrast with the <a href="https://theconversation.com/most-americans-dont-realize-what-companies-can-predict-from-their-data-110760">personally identifiable online or phone data</a> that companies collect to show you targeted ads, biobanks collect de-identified data that is evaluated in aggregate.</p>
<p>In the age of vast data collection, ensuring that participants are aware of how their data can and cannot be used is necessary to ensure that biobanks are a transparent tool for global good. Biobanks can’t predict how a participant’s data will be used in the future, so it can be difficult for researchers and ethicists to bring back the “informed” part of “informed consent.” Even so, more needs to be done to earn the trust of the valuable research participants who contribute the data to improve science and the world.</p><img src="https://counter.theconversation.com/content/208416/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robbee Wedow is a research fellow at AnalytiXIN, which is a consortium of health-data organizations, industry partners and university partners in Indiana primarily funded through the Lilly Endowment, IU Health and Eli Lilly and Company.</span></em></p>Biobanks collect and store large amounts of data that researchers use to conduct a wide range of studies. Making sure participants understand what they’re getting into can help build trust in science.Robbee Wedow, Assistant Professor of Sociology and Data Science, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2055572023-05-15T15:01:09Z2023-05-15T15:01:09ZYou shed DNA everywhere you go – trace samples in the water, sand and air are enough to identify who you are, raising ethical questions about privacy<figure><img src="https://images.theconversation.com/files/525993/original/file-20230512-24221-4caajm.png?ixlib=rb-1.1.0&rect=0%2C0%2C2121%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A casual stroll on the beach can leave enough intact DNA behind to extract identifiable information.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/human-footprint-on-the-sand-royalty-free-image/1030780262">Comezora/Moment via Getty Images</a></span></figcaption></figure><p>Human DNA can be sequenced from small amounts of water, sand and air in the environment to <a href="https://www.nature.com/articles/s41559-023-02056-2">potentially extract identifiable information</a> like genetic lineage, gender, and health risks, according to our new research.</p>
<p>Every cell of the body <a href="https://calteches.library.caltech.edu/2687/1/bonner.pdf">contains DNA</a>. Because each person has a unique genetic code, DNA can be <a href="https://theconversation.com/genetic-paparazzi-are-right-around-the-corner-and-courts-arent-ready-to-confront-the-legal-quagmire-of-dna-theft-178866">used to identify individual people</a>. Typically, medical practitioners and researchers obtain human DNA through direct sampling, such as blood tests, swabs or biopsies. However, all living things, including animals, plants and microbes, <a href="https://doi.org/10.1016/j.biocon.2014.11.019">constantly shed DNA</a>. The water, soil and even the air contain microscopic particles of biological material from living organisms.</p>
<p>DNA that an organism has shed into the environment is known as <a href="https://doi.org/10.1093/biosci/biab027">environmental DNA, or eDNA</a>. For the last couple of decades, scientists have been able to collect and sequence eDNA from soil or water samples to <a href="https://theconversation.com/fishing-for-dna-free-floating-edna-identifies-presence-and-abundance-of-ocean-life-75957">monitor biodiversity, wildlife populations</a> and <a href="https://theconversation.com/environmental-dna-how-a-tool-used-to-detect-endangered-wildlife-ended-up-helping-fight-the-covid-19-pandemic-158286">disease-causing pathogens</a>. Tracking rare or elusive endangered species <a href="https://doi.org/10.1007/s00114-019-1605-1">through their eDNA</a> has been a boon to researchers, since traditional monitoring methods such as observation or trapping can be difficult, often unsuccessful and intrusive to the species of interest.</p>
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<figcaption><span class="caption">The authors and their colleagues use environmental DNA to study sea turtles.</span></figcaption>
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<p>Researchers using eDNA tools usually focus only on the species they’re studying and disregard DNA from other species. However, humans <a href="https://theconversation.com/genetic-paparazzi-are-right-around-the-corner-and-courts-arent-ready-to-confront-the-legal-quagmire-of-dna-theft-178866">also shed</a>, cough and <a href="https://theconversation.com/who-sees-what-you-flush-wastewater-surveillance-for-public-health-is-on-the-rise-but-a-new-survey-reveals-many-us-adults-are-still-unaware-193007">flush DNA</a> into their surrounding environment. And as our team of geneticists, <a href="https://scholar.google.com/citations?user=czRqHV4AAAAJ&hl=en&oi=ao">ecologists</a> and <a href="https://scholar.google.com/citations?user=3cQ6umoAAAAJ&hl=en">marine biologists</a> in the <a href="https://scholar.google.com/citations?hl=en&user=LtNEh9gAAAAJ">Duffy Lab</a> at the University of Florida found, <a href="https://www.nature.com/articles/s41559-023-02056-2">signs of human life can be found everywhere</a> but in the most isolated locations. </p>
<h2>Animals, humans and viruses in eDNA</h2>
<p>Our team uses environmental DNA to study <a href="https://doi.org/10.1111/1755-0998.13617">endangered sea turtles and the viral tumors</a> to which they are susceptible. Tiny hatchling sea turtles shed DNA as they crawl along the beach on their way to the ocean shortly after they are born. <a href="https://doi.org/10.1111/1755-0998.13617">Sand scooped from their tracks</a> contains enough DNA to provide valuable insights into the turtles and the chelonid herpesviruses and <a href="https://theconversation.com/could-human-cancer-treatments-be-the-key-to-saving-sea-turtles-from-a-disfiguring-tumor-disease-98140">fibropapillomatosis tumors that afflict them</a>. Scooping a liter of <a href="https://doi.org/10.1038/s42003-021-02085-2">water from the tank</a> of a recovering sea turtle under veterinary care equally provides a wealth of genetic information for research. Unlike blood or skin sampling, collecting eDNA causes no stress to the animal.</p>
<p><a href="https://theconversation.com/genomic-sequencing-heres-how-researchers-identify-omicron-and-other-covid-19-variants-172935">Genetic sequencing technology</a> used to decode DNA has improved rapidly in recent years, and it is now possible to easily sequence the DNA of every organism in a sample from the environment. Our team suspected that the sand and water samples we were using to study sea turtles would also contain DNA from a number of other species – including, of course, humans. What we didn’t know was <a href="https://www.nature.com/articles/s41559-023-02056-2">just how informative</a> the human DNA we could extract would be. </p>
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<span class="caption">The researchers were able to collect intact human DNA in water samples from a river in Florida.</span>
<span class="attribution"><span class="source">Todd Osborne</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>To figure this out, we took samples from a variety of locations in Florida, including the ocean and rivers in urban and rural areas, sand from isolated beaches and a remote island never usually visited by people. We found human DNA in all of those locations except the remote island, and these samples were high quality enough for analysis and sequencing. </p>
<p>We also tested the technique in Ireland, tracing along a river that winds from a remote mountaintop, through small rural villages and into the sea at a larger town of 13,000 inhabitants. We found human DNA everywhere but in the remote mountain tributary where the river starts, far from human habitation.</p>
<p>We also collected air samples from a room in our wildlife veterinary hospital in Florida. People who were present in the room gave us permission to take samples from the air. We recovered DNA matching the people, the animal patient and common animal viruses present at the time of collection.</p>
<p>Surprisingly, the human eDNA found in the local environment was intact enough for us to identify mutations associated with disease and to determine the genetic ancestry of people who live in the area. Sequencing DNA that volunteers left in their footprints in the sand even yielded part of their sex chromosomes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram depicting eDNA collection sources and analysis workflow" src="https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526004/original/file-20230513-16755-kheuum.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Human eDNA can be collected and analyzed from a variety of sources.</span>
<span class="attribution"><span class="source">Liam Whitmore/Created with BioRender.com</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Ethical implications of collecting human eDNA</h2>
<p>Our team dubs inadvertent retrieval of human DNA from environmental samples <a href="https://www.nature.com/articles/s41559-023-02056-2">“human genetic bycatch.”</a> We’re calling for deeper discussion about how to ethically handle human environmental DNA. </p>
<p>Human eDNA could present significant advances to research in fields as diverse as conservation, epidemiology, forensics and farming. If handled correctly, human eDNA could help archaeologists <a href="https://theconversation.com/who-owned-this-stone-age-jewellery-new-forensic-tools-offer-an-unprecedented-answer-204797">track down undiscovered ancient human settlements</a>, allow biologists to <a href="https://doi.org/10.1038/s42003-021-01656-7">monitor cancer mutations in a given population</a> or provide law enforcement agencies <a href="https://doi.org/10.1016/j.forsciint.2023.111599">useful forensic information</a>.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Footprints in the sand at a beach" src="https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=899&fit=crop&dpr=1 600w, https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=899&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=899&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/525989/original/file-20230512-7632-rct90g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1130&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The researchers extracted identifiable genetic information from footprints in the sand.</span>
<span class="attribution"><span class="source">David Duffy</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>However, there are also myriad ethical implications relating to the inadvertent or deliberate collection and analysis of human genetic bycatch. Identifiable information can be extracted from eDNA, and accessing this level of detail about individuals or populations comes with <a href="https://theconversation.com/how-a-south-african-communitys-request-for-its-genetic-data-raises-questions-about-ethical-and-equitable-research-166940">responsibilities relating to consent and confidentiality</a>.</p>
<p>While we conducted our study with the approval of our <a href="https://doi.org/10.2146/ajhp070066">institutional review board</a>, which ensures that studies on people adhere to ethical research guidelines, there is no guarantee that everyone will treat this type of information ethically. </p>
<p>Many questions arise regarding human environmental DNA. For instance, who should have access to human eDNA sequences? Should this information be made publicly available? Should consent be required before taking human eDNA samples, and from whom? Should researchers remove human genetic information from samples originally collected to identify other species?</p>
<p>We believe it is vital to implement regulations that ensure collection, analysis and data storage are carried out ethically and appropriately. Policymakers, scientific communities and other stakeholders need to take human eDNA collection seriously and balance consent and privacy against the possible benefits of studying eDNA. Raising these questions now can help ensure everyone is aware of the capabilities of eDNA and provide more time to develop protocols and regulations to ensure appropriate use of eDNA techniques and the ethical handling of human genetic bycatch.</p><img src="https://counter.theconversation.com/content/205557/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jessica Alice Farrell received funding from the Gumbo Limbo Nature Center d/b/a Friends of Gumbo Limbo (a 501c3 non-profit organization) through a generous donation through their Graduate Research Grant programme</span></em></p><p class="fine-print"><em><span>Jenny Whilde does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Environmental DNA provides a wealth of information for conservationists, archaeologists and forensic scientists. But the unintentional pickup of human genetic information raises ethical questions.Jenny Whilde, Adjunct Research Scientist in Marine Bioscience, University of FloridaJessica Alice Farrell, Postdoctoral associate, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1684892021-09-28T20:09:48Z2021-09-28T20:09:48ZCurious Kids: how does our DNA relate to our personality and appearance?<figure><img src="https://images.theconversation.com/files/423485/original/file-20210928-18-1gwfy8g.jpeg?ixlib=rb-1.1.0&rect=77%2C252%2C6402%2C4653&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><blockquote>
<p>How does our DNA relate to our personality and appearance? — Emma, age 9, Sydney</p>
</blockquote>
<p><a href="https://theconversation.com/au/topics/curious-kids-36782"><img src="https://images.theconversation.com/files/291898/original/file-20190911-190031-enlxbk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=90&fit=crop&dpr=1" width="100%"></a></p>
<p>Hi Emma. Thank you for this great question!</p>
<p>Our body is made up of trillions of cells, each of which has a nucleus that holds our DNA. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Human cell diagram" src="https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423476/original/file-20210928-26-2bh8nx.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Our DNA is contained within the nucleus in each cell in our body, much too small for our eyes to see!</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Our DNA is made up of more than 20,000 genes. You can think of genes as the the instructions which help decide what we look like, how our bodies work and even our personalities. </p>
<p>We get half our genes from our biological mother and the other half from our father. That’s why we don’t look exactly like our parents, but we may look a bit like them — and may also think and act similarly to them. </p>
<p>That said, each of us still has a unique collection of genes overall. That means no two people carry exactly the same genes, not even brothers and sisters. And that’s why each of us has a unique appearance and personality.</p>
<h2>What do our genes decide?</h2>
<p>Our genes help explain many parts of our appearance, like how tall we are and the colour of our eyes.</p>
<p>They also have a hand in our other skills, such as how fast we can run, how good we are at solving problems, and whether we enjoy talking to new people (rather than if we feel shy).</p>
<p>By studying a person’s genes, scientists can tell whether that person is more likely to have blue or brown eyes, without even seeing them.</p>
<p>They may also be able to tell that person how likely they are to develop certain medical conditions later in life, such as cancer or myopia (when you can’t see far-off objects as clearly).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Glasses held out to focus on tree tops in the distance" src="https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423479/original/file-20210928-26-19vv5g6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Myopia (also called ‘nearsightedness’) is the common eye condition where objects become blurrier the further away they are. Myopia doesn’t just happen to adults — kids can have it too! Luckily glasses can easily fix the problem.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-people-get-cancer-106069">Curious Kids: Why do people get cancer?</a>
</strong>
</em>
</p>
<hr>
<h2>Not everything is determined by genes and DNA</h2>
<p>Although genes are important, they’re not the only reason for why we look, think, feel and act as we do — or why we’re more likely to have certain diseases. While some traits such as <a href="https://www.nature.com/articles/s41433-021-01749-x">eye colour</a> are mainly determined by our genes, an eye injury can change someone’s eye colour. </p>
<p>Our habits, such as how much we eat and exercise, also have a big impact on who we are and what we look like. If you eat too much junk, you’ll probably get chubby and start running slower, regardless of the genes your parents gave you. </p>
<p>Our environment at home, school and/or work play a key role in shaping us, too. Take myopia. Before the discovery of the more than <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7145443/">400 genes for myopia</a>, scientists noticed children are at least three times more likely to be myopic if <a href="https://iovs.arvojournals.org/article.aspx?articleid=2162292">either one or both parents are</a>. They realised if someone has trouble seeing far-off objects, there’s a decent chance this is related to genetics.</p>
<p>At the same time, however, there is currently a surge <a href="https://pubmed.ncbi.nlm.nih.gov/26875007/">in myopia</a> happening around the world, with more people becoming myopic even though their parents are not!</p>
<p>Researchers discovered our environments and habits play a <a href="https://www.sciencedirect.com/science/article/pii/S1350946212000444?casa_token=k8_vRWGdaf8AAAAA:wDxO0QffQyxIruw4eQjThye7syHmpYo-LmFK82-19SkOZ50Wq7lqJ0udehfxt9-xfnWQZZHHBg">huge role in myopia development</a>. For instance, they found myopia (and the need to wear glasses) is more likely to happen among people living in cities rather than the country, and those who spend less time outdoors. </p>
<p>The way we perceive colour is also influenced by both our genes and environment. You might remember the social media trend of <a href="https://en.wikipedia.org/wiki/The_dress">#thedress</a> that went viral back in 2015.</p>
<p>The world was torn over whether the dress (below) is actually blue and black, or white and gold. Researchers later found the way we see colour in this dress is 34% related to <a href="https://jov.arvojournals.org/article.aspx?articleid=2599740">our genes</a> and 66% linked to environmental factors.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The dress that become a viral internet sensation in 2015." src="https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423481/original/file-20210928-32-obctqn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Looking at this photo you will either see a dress that is blue and black, or white and gold. Amazingly, the answer is different for different people.</span>
<span class="attribution"><span class="source">Wikimedia</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-are-people-colour-blind-107599">Curious Kids: why are people colour blind?</a>
</strong>
</em>
</p>
<hr>
<h2>Genes and personality</h2>
<p>“Personality” describes the relatively stable ways in which people think, feel and act. And again, genes do a pretty good job of explaining why some people are more <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbb.12439">outgoing and energetic, while others tend to be more moody and anxious</a>. </p>
<p>Our genes also help explain how smart we are. But one surprising finding is <a href="https://www.nature.com/articles/mp2014105">our genes have more of an effect on us as we age</a>. Among children, about 40% of the differences in intelligence scores are explained by genes. In young adults, this increases to about 60%, even though it’s the same genes that continue to affect intelligence. </p>
<p>This is most likely because <a href="https://pubmed.ncbi.nlm.nih.gov/23818655/">our genes can impact which environments we prefer</a>, and adults often act on their preferences.</p>
<p>For example, most adults do not get told when to go to bed at night! And adults who enjoy learning new things can choose to spend their time in libraries and art museums, or taking classes. In other words, adults can choose the environments and activities that best express their genes. </p>
<h2>The future is in your hands</h2>
<p>You can think of your genes as a way to understand yourself — but not as a way to make decisions. For example, just because someone’s parents may not have been able to go to university, they themselves can if they study hard.</p>
<p>Or, a person’s parents may be overweight, but that doesn’t mean they have to be. They can still join a sprint team if they’re willing to put in the effort.</p>
<p>Even though your DNA and genes shape a lot of your personality and appearance, remember: they <em>do not</em> determine your life story.</p><img src="https://counter.theconversation.com/content/168489/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Mackey receives funding through a National Health and Medical Research Council Practitioner Fellowship.</span></em></p><p class="fine-print"><em><span>Samantha Lee and Serena Wee do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Understanding your genes is a great way to understand certain things about yourself — yet, who we are is determined by so much more than just DNA.Samantha Lee, Adjunct Research Fellow, Centre for Ophthalmology and Visual Science, The University of Western AustraliaDavid Mackey, Professor of Ophthalmology, The University of Western AustraliaSerena Wee, Senior Lecturer in Work Psychology, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1665712021-08-24T04:37:57Z2021-08-24T04:37:57ZWhy has same-sex sexual behaviour persisted during evolution?<p>Same-sex sexual behaviour may seem to present a Darwinian paradox. It provides no obvious reproductive or survival benefit, and yet same-sex sexual behaviour is fairly common — around <a href="https://journals.sagepub.com/doi/10.1177/1529100616637616">2-10% of individuals</a> in <a href="https://pubmed.ncbi.nlm.nih.gov/27593894/">diverse human societies</a> — and is clearly <a href="https://science.sciencemag.org/content/365/6456/eaat7693">influenced by genes</a>.</p>
<p>These observations raise the question: why have genes associated with same-sex sexual behaviour been maintained over evolutionary time? Given that evolution depends on genes being passed down through the generations via reproduction, how and why were these genes passed down too?</p>
<p>In a new paper <a href="https://www.nature.com/articles/s41562-021-01168-8">published in Nature Human Behaviour</a>, my colleagues and I tested one possible explanation: that the genes associated with same-sex sexual behaviour have evolutionarily advantageous effects in people who <em>don’t</em> engage in same-sex sexual behaviour. </p>
<p>Specifically, we tested whether those genes are also associated with having more opposite-sex partners, which might therefore confer an evolutionary advantage. </p>
<p>To investigate this, we used genetic data from more than 350,000 people who had participated in the <a href="https://www.ukbiobank.ac.uk/">UK Biobank</a>, a huge database of genetic and health information. </p>
<p>These participants reported whether they had ever had a same-sex partner, and also how many opposite-sex partners they had had in their lifetime. </p>
<p>We analysed the association of millions of individual genetic variants with each of these self-reported variables. For both variables, there were not only one or a few associated genetic variants, but very many, spread throughout the genome. Each had only a tiny effect, but in aggregate, their effects were substantial. </p>
<p>We then showed that the aggregate genetic effects associated with ever having had a same sex partner were also associated — among people who had <em>never</em> had a same-sex partner — with having had more opposite-sex partners. </p>
<p>This result supported our main hypothesis. </p>
<h2>Further exploration</h2>
<p>We then tried replicating and extending our findings.</p>
<p>First, we successfully replicated the main finding in an independent sample. </p>
<p>Second, we tested whether our results still held true if we used different definitions of same-sex sexual behaviour.</p>
<p>For example, did it still hold true if we tightened the definition of same-sex sexual behaviour to cover only those individuals with <em>predominantly</em> or <em>exclusively</em> same-sex partners (rather than including anyone who has ever had one)?</p>
<p>Our results remained largely consistent, although statistical confidence was lower due to the smaller sub-samples used. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/gay-gene-search-reveals-not-one-but-many-and-no-way-to-predict-sexuality-122459">'Gay gene' search reveals not one but many – and no way to predict sexuality</a>
</strong>
</em>
</p>
<hr>
<p>Third, we tested whether physical attractiveness, risk-taking propensity, and openness to experience might help to account for the main result. </p>
<p>In other words, could genes associated with these variables be associated with both same-sex sexual behaviour and with opposite-sex partners in heterosexuals?</p>
<p>In each case, we found evidence supporting a significant role for these variables, but most of the main result remained unexplained. </p>
<p>So we still don’t have a solid theory on exactly how these genes confer an evolutionary advantage. But it might be a complex mix of factors that generally make someone “more attractive” in broad terms.</p>
<h2>Simulating evolution</h2>
<p>To investigate how the hypothesised evolutionary process might unfold, we also constructed a digital simulation of a population of reproducing individuals over many generations. These simulated individuals had small “genomes” that affected their predispositions for having same-sex partners and opposite-sex reproductive partners. </p>
<p>These simulations showed that, in principle, the kind of effect suggested by our main result can indeed maintain same-sex sexual behaviour in the population, even when the trait itself is evolutionarily disadvantageous. </p>
<figure class="align-center ">
<img alt="Two men hold hands while walking on grass" src="https://images.theconversation.com/files/417533/original/file-20210824-19-1bv9ra9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/417533/original/file-20210824-19-1bv9ra9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/417533/original/file-20210824-19-1bv9ra9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/417533/original/file-20210824-19-1bv9ra9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/417533/original/file-20210824-19-1bv9ra9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/417533/original/file-20210824-19-1bv9ra9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/417533/original/file-20210824-19-1bv9ra9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The study involved Western participants - so the next step will be to look at other populations.</span>
<span class="attribution"><span class="source">Stanley Dai/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Crucially, our simulations also showed that if there were no countervailing benefit to genes associated with same-sex sexual behaviour, the behaviour would likely disappear from the population. </p>
<p>These findings give us intriguing clues about the evolutionary maintenance of same-sex sexual behaviour, but there are important caveats too. </p>
<p>An important limitation is that our results are based on modern, Western samples of white participants – we cannot know to what extent our findings apply to other ethnicities or cultures in different places and times. Future studies using more diverse samples may help clarify this. </p>
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<em>
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Read more:
<a href="https://theconversation.com/african-scientists-recognise-that-diverse-sexuality-is-the-norm-43050">African scientists recognise that diverse sexuality is the norm</a>
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<p>On a final note, I am aware some people believe it is inappropriate to study sensitive topics such as the genetics and evolution of same-sex sexual behaviour. My perspective is that the science of human behaviour aims to shine a light on the mysteries of human nature and that this involves understanding the factors that shape our commonalities and our differences. </p>
<p>Were we to avoid studying sexual preference or other such topics due to political sensitivities, we would be leaving these important aspects of normal human diversity in the dark.</p><img src="https://counter.theconversation.com/content/166571/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brendan Zietsch received funding from the Australian Research Council.</span></em></p>Same-sex sexual behaviour presents a paradox: it’s influenced by genes, but how and why do these genes continue to be passed down the generations? One theory is they have reproductive benefits too.Brendan Zietsch, Associate Professor, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1624182021-06-09T07:32:59Z2021-06-09T07:32:59ZWhy it took 20 years to ‘finish’ the human genome — and why there’s still more to do<figure><img src="https://images.theconversation.com/files/405260/original/file-20210609-27-1n86l2m.png?ixlib=rb-1.1.0&rect=0%2C2%2C752%2C357&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Human_genome.png">Webridge/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>The release of the <a href="https://www.nature.com/articles/35057062">draft human genome sequence</a> in 2001 was a seismic moment in our understanding of the human genome, and paved the way for advances in our understanding of the genomic basis of human biology and disease.</p>
<p>But sections were left unsequenced, and some sequence information was incorrect. Now, two decades later, we have a much more complete version, <a href="https://www.biorxiv.org/content/10.1101/2021.05.26.445798v1">published as a preprint</a> (which is yet to undergo peer review) by an international consortium of researchers.</p>
<p>Technological limitations meant the original draft human genome sequence covered just the “euchromatic” portion of the genome — the 92% of our genome where most genes are found, and which is most active in making gene products such as RNA and proteins. </p>
<p>The newly updated sequence fills in most of the remaining gaps, providing the full 3.055 billion base pairs (“letters”) of our DNA code in its entirety. This data has been made publicly available, in the hope other researchers will use it to further their research.</p>
<h2>Why did it take 20 years?</h2>
<p>Much of the newly sequenced material is the “heterochromatic” part of the genome, which is more “tightly packed” than the euchromatic genome and contains many highly repetitive sequences that are very challenging to read accurately.</p>
<p>These regions were once thought not to contain any important genetic information but they are now known to contain genes that are involved in fundamentally important processes such as the formation of organs during embryonic development. Among the 200 million newly sequenced base pairs are an estimated 115 genes predicted to be involved in producing proteins. </p>
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<em>
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Read more:
<a href="https://theconversation.com/explainer-what-is-the-human-genome-project-7559">Explainer: what is the Human Genome Project?</a>
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<p>Two key factors made the completion of the human genome possible:</p>
<p><strong>1. Choosing a very special cell type</strong></p>
<p>The newly published genome sequence was created using human cells derived from a very rare type of tissue called a complete <a href="https://www.thewomens.org.au/health-information/pregnancy-and-birth/pregnancy-problems/early-pregnancy-problems/hydatidiform-mole">hydatidiform mole</a>, which occurs when a fertilised egg loses all the genetic material contributed to it by the mother.</p>
<p>Most cells contain two copies of each chromosome, one from each parent and each parent’s chromosome contributing a different DNA sequence. A cell from a complete hydatidiform mole has two copies of the father’s chromosomes only, and the genetic sequence of each pair of chromosomes is identical. This makes the full genome sequence much easier to piece together.</p>
<p><strong>2. Advances in sequencing technology</strong></p>
<p>After decades of glacial progress, the Human Genome Project achieved its 2001 breakthrough by pioneering a method called “shotgun sequencing”, which involved breaking the genome into very small fragments of about 200 base pairs, <a href="https://www.genome.gov/genetics-glossary/Bacterial-Artificial-Chromosome">cloning them inside bacteria</a>, deciphering their sequences, and then piecing them back together like a giant jigsaw.</p>
<p>This was the main reason the original draft covered only the euchromatic regions of the genome — only these regions could be reliably sequenced using this method.</p>
<p>The latest sequence was deduced using two complementary new DNA-sequencing technologies. One was developed by PacBio, and allows longer DNA fragments to be sequenced with very high accuracy. The second, developed by Oxford Nanopore, produces ultra-long stretches of continuous DNA sequence. These new technologies allows the jigsaw pieces to be thousands or even millions of base pairs long, making it easier to assemble.</p>
<p>The new information has the potential to advance our understanding of human biology including how chromosomes function and maintain their structure. It is also going to improve our understanding of genetic conditions such as Down syndrome that have an underlying chromosomal abnormality.</p>
<h2>Is the genome now completely sequenced?</h2>
<p>Well, no. An obvious omission is the Y chromosome, because the complete hydatidiform mole cells used to compile this sequence contained two identical copies of the X chromosome. However, this work is underway and the researchers anticipate their method can also accurately sequence the Y chromosome, despite it having highly repetitive sequences.</p>
<p>Even though sequencing the (almost) complete genome of a human cell is an extremely impressive landmark, it is just one of several crucial steps towards fully understanding humans’ genetic diversity.</p>
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<strong>
Read more:
<a href="https://theconversation.com/how-much-junk-is-in-our-dna-53929">How much ‘junk’ is in our DNA?</a>
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<p>The next job will be to study the genomes of diverse populations (the complete hydatidiform mole cells were European). Once the new technology has matured sufficiently to be used routinely to sequence many different human genomes, from different populations, it will be better positioned to make a more significant impact on our understanding of human history, biology and health. </p>
<p>Both care and technological development are needed to ensure this research is conducted with a full understanding of the diversity of the human genome to prevent exacerbation of health disparities by limiting discoveries to specific populations.</p><img src="https://counter.theconversation.com/content/162418/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Melissa Southey receives funding from the NHMRC, NBCF, PCFA, NIH (USA), VCA, CCV, DJPR (VIC) and Monash University. She is affiliated with Cancer Council Victoria and The University of Melbourne. </span></em></p><p class="fine-print"><em><span>Tu Nguyen-Dumont is a recipient of a Fellowship from the National Breast Cancer Foundation (ECF-17-001).</span></em></p>Two decades after the ‘full’ human genetic code was released to global fanfare, researchers have finally filled in the blanks that made up 8% of the sequence, thanks to recent advances in genome sequencing.Melissa Southey, Chair Precision Medicine, Monash UniversityTu Nguyen-Dumont, Senior research fellow, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1559752021-02-25T13:12:30Z2021-02-25T13:12:30ZYour genetics influence how resilient you are to cold temperatures – new research<figure><img src="https://images.theconversation.com/files/386410/original/file-20210225-17-1b8ov4c.jpg?ixlib=rb-1.1.0&rect=26%2C4%2C3000%2C1989&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People with this gene variant shivered less and had a higher core body temperature when exposed to cold water.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-man-bathing-ice-hole-237474358">Dudarev Mikhail/ Shutterstock</a></span></figcaption></figure><p>Some people just aren’t bothered by the cold, no matter how low the temperature dips. And the reason for this may be in a person’s genes. Our <a href="https://www.cell.com/ajhg/fulltext/S0002-9297(21)00013-6">new research</a> shows that a common genetic variant in the skeletal muscle gene, ACTN3, makes people more resilient to cold temperatures.</p>
<p>Around one in five people lack a <a href="https://www.nature.com/articles/ng0499_353">muscle protein called alpha-actinin-3</a> due to a single genetic change in the ACTN3 gene. The absence of alpha-actinin-3 became more common as some modern humans migrated out of Africa and into the <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0052282">colder climates</a> of Europe and Asia. The reasons for this increase have remained unknown until now.</p>
<p>Our <a href="https://www.sciencedirect.com/science/article/pii/S0002929721000136?via%3Dihub">recent study</a>, conducted alongside researchers from Lithuania, Sweden and Australia, suggests that if you’re alpha-actinin-3 deficient, then your body can maintain a higher core temperature and you shiver less when exposed to cold, compared with those who have alpha-actinin-3.</p>
<p>We looked at 42 men aged 18 to 40 years from Kaunas in southern Lithuania and exposed them to cold water (14°C) for a maximum of 120 minutes, or until their core body temperature reached 35.5°C. We broke their exposure up into 20-minute periods in the cold with ten-minute breaks at room temperature. We then separated participants into two groups based on their ACTN3 genotype (whether or not they had the alpha-actinin-3 protein).</p>
<p>While only 30% of participants with the alpha-actinin-3 protein reached the full 120 minutes of cold exposure, 69% of those that were alpha-actinin-3 deficient completed the full cold-water exposure time. We also assessed the amount of shivering during cold exposure periods, which told us that those without alpha-actinin-3 shiver less than those who have alpha-actinin-3.</p>
<p>Our study suggests that genetic changes caused by the loss of alpha-actinin-3 in our skeletal muscle affect how well we can tolerate cold temperatures, with those that are alpha-actinin-3 deficient better able to maintain their body temperature and conserve their energy by shivering less during cold exposure. However, future research will need to investigate whether similar results would be seen in women.</p>
<h2>ACTN3’s role</h2>
<p>Skeletal muscles are made up of two types of muscle fibres: fast and slow. Alpha-actinin-3 is predominantly found in fast muscle fibres. These fibres are responsible for the rapid and forceful contractions used during sprinting, but typically fatigue quickly and are prone to injury. Slow muscle fibres on the other hand generate less force but are resistant to fatigue. These are primarily the muscle you’d use during endurance events, like marathon running.</p>
<p>Our previous work has shown that ACTN3 variants play an important role in our muscle’s ability to generate strength. We showed that the <a href="https://www.sciencedirect.com/science/article/pii/S0002929707620242?via%3Dihub">loss of alpha-actinin-3</a> is detrimental to sprint performance in athletes and the general population, but may benefit muscle endurance. </p>
<p>This is because the loss of alpha-actinin-3 causes the muscle to behave more like a slower muscle fibre. This means that alpha-actinin-3 deficient muscles are weaker but recover more quickly from fatigue. But while this is <a href="https://pubmed.ncbi.nlm.nih.gov/18650267/">detrimental to sprint performance</a>, it may be beneficial during more endurance events. This improvement in endurance muscle capacity could also influence our response to cold.</p>
<p>While alpha-actinin-3 deficiency does not cause muscle disease, it does influence how our muscle functions. Our study shows that ACTN3 is more than just the “gene for speed”, but that its loss improves our muscle’s ability to generate heat and reduces the need to shiver when exposed to cold. This improvement in muscle function would conserve energy and ultimately increase survival in cold temperatures, which we think is a key reason why we see an increase in alpha-actinin-3 deficient people today, as this would have helped modern humans better tolerate cooler climates as they migrated out of Africa.</p>
<p>The goal of our research is to improve our understanding of how our genetics influence how our muscle works. This will allow us to develop better treatments for those who suffer from muscle diseases, like <a href="https://www.nature.com/articles/ncomms14143">Duchenne muscular dystrophy</a>, as well as more common conditions, such as obesity and type 2 diabetes. A better understanding of how variants in alpha-actinin-3 influences these conditions will give us better ways to treat and prevent these conditions in the future.</p><img src="https://counter.theconversation.com/content/155975/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Around 1.5 billion people worldwide have this common genetic variant.Victoria Wyckelsma, Postdoctoral Research Fellow, Muscle Physiology, Karolinska InstitutetPeter John Houweling, Senior Research Officer, Neuromuscular Research, Murdoch Children's Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1467652020-09-28T19:59:08Z2020-09-28T19:59:08ZThere’s no single gene for left-handedness. At least 41 regions of DNA are involved<figure><img src="https://images.theconversation.com/files/360180/original/file-20200928-22-12vzevi.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4288%2C2843&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Most people consistently use the same hand to do tasks that require skill and control such as writing or threading a needle. We know genetics plays a big part in which hand a person prefers, but it has been difficult to identify the exact genes responsible. </p>
<p>To find out more, we <a href="https://doi.org/10.1038/s41562-020-00956-y">analysed</a> the DNA of more than 1.7 million people and discovered 41 regions of the genome associated with being left handed and another seven associated with being ambidextrous.</p>
<h2>What makes people left-handed?</h2>
<p>About 88% of people prefer to use their right hand for complex tasks, around 10% prefer their left hand, and the other 2% report they do not have a preference and can use either hand. Hand preference develops so early that it can be seen <a href="https://www.sciencedirect.com/science/article/abs/pii/S0028393204002428">in the womb</a>. </p>
<p>Handedness tends to stabilise around the time children are learning to draw. In the absence of injury or training it remains constant throughout life. Evidence from historic human populations suggests it has been this way for <a href="https://www.tandfonline.com/doi/abs/10.1080/1357650X.2010.529451">hundreds of thousands of years</a>.</p>
<p>Research examining patterns of handedness in twins and families shows most of the variation is down to non-genetic factors, such as training and the environment in which we gain early motor skills. However, genetics does play <a href="https://www.sciencedirect.com/science/article/abs/pii/S0028393208003722">a significant role</a>. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ive-always-wondered-can-animals-be-left-and-right-pawed-83716">I've always wondered: can animals be left- and right-pawed?</a>
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<h2>There is no single gene for handedness</h2>
<p>Since the mid-1980s more than 100 journal articles have explored the idea that a single gene might influence handedness. These <a href="https://books.google.com.au/books/about/Left_Right_Hand_and_Brain.html?id=3Y4oAAAAYAAJ&redir_esc=y">theories</a> suggested one variant of the gene would bias an individual towards right-handedness, while the alternate variant led to handedness being randomly determined.</p>
<p>While there have been many theories attempting to explain different human characteristics via single genes, in recent years we have discovered that the reality is often much more complicated. More recent research uses <a href="https://www.genome.gov/about-genomics/fact-sheets/Genome-Wide-Association-Studies-Fact-Sheet">genome-wide association studies</a> (GWAS) to look for a relationship between a trait of interest and the number of copies of a genetic variant someone has. These analyses are run for millions of variants located across the genome. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-much-junk-is-in-our-dna-53929">How much ‘junk’ is in our DNA?</a>
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</em>
</p>
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<p>These genome-wide studies have shown that almost all human traits are influenced by many hundreds or thousands of genetic variants. Often these variants are located between genes whose purpose is not clearly identifiable, in what used to be called “junk DNA”. </p>
<p>GWAS has also shown most traits are influenced by large numbers of genes which each contribute a very small effect, rather than a single gene which has a large effect. To track these small effects, large collaborative studies with many participants are required in order to identify the individual genetic variants involved.</p>
<h2>What GWAS reveals about handedness</h2>
<p>In 2009 we started a project involving researchers from around the world to hunt for genetic variants that influence handedness using GWAS. We did not recruit participants based on their handedness, so the number of left-handed people was relatively small. As a result, we have only recently gathered enough to undertake robust analyses.</p>
<p>Our <a href="https://doi.org/10.1038/s41562-020-00956-y">study</a> brought together analyses of data from 1,766,671 people. Of these people, 194,198 were left-handed and 37,637 were ambidextrous. We found 41 regions of the genome associated with left-handedness and seven regions associated with ambidexterity. </p>
<p>Many of the regions of the genome associated with left-handedness contained genes that code for microtubule proteins. These proteins play important roles during development in the migration of neurons and in the ability of the brain to adapt to changes in the environment. </p>
<figure class="align-center ">
<img alt="A young girl writing on a blackboard with both hands at the same time." src="https://images.theconversation.com/files/360210/original/file-20200928-18-wngw1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/360210/original/file-20200928-18-wngw1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=475&fit=crop&dpr=1 600w, https://images.theconversation.com/files/360210/original/file-20200928-18-wngw1n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=475&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/360210/original/file-20200928-18-wngw1n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=475&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/360210/original/file-20200928-18-wngw1n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=597&fit=crop&dpr=1 754w, https://images.theconversation.com/files/360210/original/file-20200928-18-wngw1n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=597&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/360210/original/file-20200928-18-wngw1n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=597&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Only around 2% of people are ambidextrous, and it may be caused by completely different genes than those responsible for left-handedness.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Interestingly, genes that influence <a href="https://www.theguardian.com/science/blog/2016/sep/08/situs-inversus-and-my-through-the-looking-glass-body">other asymmetries</a> in the body, such as <a href="https://rarediseases.info.nih.gov/diseases/6268/dextrocardia-with-situs-inversus">which side</a> of the body <a href="https://rarediseases.info.nih.gov/diseases/4883/situs-inversus">the heart</a> is located on, were not associated with handedness in our study.</p>
<p>Another important finding was that there was little overlap between the regions of the genome associated with left-handedness and those associated with ambidexterity. This suggests that ambidexterity is more complicated than we previously thought. The mechanisms that influence the <em>direction</em> of hand preference might be different from those that influence the <em>degree</em> of hand preference. </p>
<p>These findings give us promising new leads but more work is needed to identify further genetic variants that influence handedness. There is also a long way to go before we understand how these variants play a role in someone becoming right-handed, left-handed or ambidextrous.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/is-there-life-through-the-looking-glass-the-riddle-of-lifes-single-handedness-48819">Is there life through the looking-glass? The riddle of life's single-handedness</a>
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</p>
<hr>
<img src="https://counter.theconversation.com/content/146765/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Evans receives funding from the National Health and Medical Research Council of Australia and the Wellcome Trust. </span></em></p><p class="fine-print"><em><span>Sarah Medland receives funding from the Australian National Health and Medical Research Council and the Medical Research Future Fund. </span></em></p>A study of more than 1.7 million people has revealed 41 distinct genetic regions associated with left-handedness, and another 7 tied to ambidexterity.David Evans, Professor of Statistical Genetics, The University of QueenslandSarah Medland, Cordinator Mental Health Research Program, QIMR Berghofer Medical Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1463982020-09-17T19:50:14Z2020-09-17T19:50:14ZWhy we need a global citizens’ assembly on gene editing<figure><img src="https://images.theconversation.com/files/358550/original/file-20200917-24-1wko0xl.jpg?ixlib=rb-1.1.0&rect=206%2C188%2C5784%2C3799&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Developments in <a href="https://theconversation.com/au/topics/gene-editing-18986">gene editing</a> are often met with moral panic. Every new announcement raises outrage over the audacity of scientists “playing God”. The existence of <a href="https://theconversation.com/mutant-malaria-parasites-resistant-to-antimalarial-atovaquone-cannot-spread-new-research-57359">mutant mosquitoes</a> and <a href="https://edition.cnn.com/2019/08/16/opinions/gene-edit-dangers-opinion-klitzman/index.html">designer babies</a> are often framed as threats – evidence that science fiction has crossed over into real life.</p>
<p>There are clear dangers when the language of fear and scandal hijack public conversations on complex matters. But this doesn’t mean we should leave the discussion on genome editing – the process of altering an organism’s genetic sequence to produce favourable characteristics or remove unwanted ones – solely to scientists.</p>
<p>That danger was sharply underscored in 2018, when a young Chinese researcher announced he had engineered the birth of what may very well be the <a href="https://theconversation.com/designer-babies-wont-be-common-anytime-soon-despite-recent-crispr-twins-108342">first genetically modified humans</a>. “I feel proud,” he told the public, a year before he was <a href="https://www.sciencemag.org/news/2019/12/chinese-scientist-who-produced-genetically-altered-babies-sentenced-3-years-jail">jailed for forgery</a>.</p>
<p>And so we reach an impasse. As global leaders face pressure to regulate genome editing, questions about who drives these ethical debates persist. Should leaders listen to scientists, who may be vulnerable to moral blindness, or to the public, some of whom may be convinced their last Whopper contained a Frankenfood patty because an Instagram influencer told them so?</p>
<h2>The impasse doesn’t have to be permanent</h2>
<p>In recent years, ordinary citizens have become more empowered to collectively learn, deliberate, reflect, and put forward recommendations on divisive and technical policy issues. The <a href="https://www.oecd.org/gov/innovative-citizen-participation-and-new-democratic-institutions-339306da-en.htm">OECD</a> calls this the “<a href="https://carnegieeurope.eu/2019/11/26/new-wave-of-deliberative-democracy-pub-80422">deliberative wave</a>”. Processes like citizen juries or online town halls have been used to provide public input not only on topical issues such as <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1369-7625.2010.00637.x">e-health</a> or <a href="https://www.tandfonline.com/doi/abs/10.1080/13549839708725520?journalCode=cloe20">waste management</a>, but also on issues that affect future generations, like <a href="https://connect2parliament.com/resources/">mitochondiral donation</a>.</p>
<p><a href="https://citizensassemblies.org/">Citizens’ assemblies</a> are forums in which a randomly selected, demographically diverse group of laypeople come together, typically for several days at a time, to deliberate over a policy issue. This allows them to learn more about the issue, scrutinise expert information, engage the arguments of advocates representing different sides, and deliberate with their fellow participants about possible ways forward.</p>
<p>These assemblies can be viewed as a counterbalance to the growing prevalence of public conversations shaped by disinformation, clickbait culture, hyper-partisanship, and distrust of experts.</p>
<p>A citizens’ assembly is a fitting approach to clarify controversies on genome editing, particularly around its ethics.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Embryo modification illustration" src="https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=348&fit=crop&dpr=1 600w, https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=348&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=348&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=437&fit=crop&dpr=1 754w, https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=437&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/358551/original/file-20200917-20-1r0pmxw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=437&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A citizens’ assembly on gene editing would allow for democratic deliberation on the risks involved.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>A groundbreaking global experiment</h2>
<p>We are among 25 experts on deliberative democracy and genome editing who have <a href="https://science.sciencemag.org/cgi/doi/10.1126/science.abb5931">published an article today in the journal Science</a>, making a case for a <a href="https://www.globalca.org/">Global Citizens’ Assembly on Genome Editing</a> </p>
<p>We envisage a process that would convene at least 100 people from all over the world, none of whom can claim expertise or a history of advocacy on this issue. After learning about the issue from a national perspective, they would gather for five days to deliberate over whether there should be a set of global principles for the regulation of genome editing technologies. The challenge of getting a representative sample of the world is not lost on us, although we are committed to ensuring a broad spread of participants representing different nationalities, ages, religions, levels of education, genders and cultures. </p>
<p>This would be a groundbreaking global experiment. It would be the first example of a global citizens’ assembly, and it remains to be seen whether national governments and institutions such as the World Health Organisation and the Food and Agriculture Organisation would seriously consider its recommendations.</p>
<p>But there are good reasons to think our global citizens’ assembly would be a meaningful undertaking.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of a round table" src="https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=574&fit=crop&dpr=1 600w, https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=574&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=574&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=721&fit=crop&dpr=1 754w, https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=721&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/358552/original/file-20200917-18-u5zhop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=721&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An effective citizens’ assembly would have participants from varying backgrounds and demographics, to be as inclusive as possible.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Evolving evidence</h2>
<p>A decade ago, the idea of citizens’ assemblies may have been dismissed by sceptics as pie in the sky. Here in Australia, the idea of a citizens’ assembly may have been tarnished by its identification with a partisan agenda, such as when former prime minister <a href="https://www.tandfonline.com/doi/full/10.1080/10361146.2013.786675?casa_token=nEsR3ITZtQ4AAAAA%3A3AQpuwuK34KX-XgyaQeItF4cLzAkaze3QS4v-S1yXq1B9w2BmN9ocI9L9KgmG2fCdrX9a8kRtyQjq1w">Julia Gillard</a> called for a citizens’ assembly on climate change. But today, citizens’ assemblies have begun to establish a credible track record.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-novel-idea-on-climate-change-ask-the-people-1962">A novel idea on climate change: ask the people</a>
</strong>
</em>
</p>
<hr>
<p>Last year, French President Emmanuel Macron invited 150 randomly selected citizens to consider ways to reduce the country’s carbon emissions by at least 40% within a decade. <a href="https://www.france24.com/en/20200622-french-citizens-council-on-the-environment-proposes-making-ecocide-illegal">Over nine months</a>, the assembly listened to more than 100 climate experts, with communications experts also on hand to help answer technical questions. </p>
<p>An assembly that included a 16-year-old student, a bus driver and a former fireman engaged in rigorous deliberation on the complex issues involved in ecological transition, even as a pandemic was unfolding. In the end, among other recommendations, the assembly endorsed making <a href="https://www.euronews.com/living/2020/06/25/france-wants-to-make-hurting-the-planet-illegal-but-what-is-ecocide">ecocide</a> a criminal act. Macron promised to put this recommendation to a national referendum.</p>
<p>There are many other examples of citizens’ assemblies that have contributed to enriching public conversations and policy-making. The Canadian province of British Columbia set up a <a href="https://participedia.net/case/1">Citizens’ Assembly on Electoral Reform</a> that successfully preceded a referendum. And the <a href="https://participedia.net/case/5316">Irish Citizens’ Assembly</a> on abortion and same-sex marriage informed a divisive debate about constitutional reform.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fearmongering-is-scary-not-genetic-technologies-themselves-92171">Fearmongering is scary, not genetic technologies themselves</a>
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</em>
</p>
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<p>The stakes are high in the Global Citizens’ Assembly on Genome Editing. On the line are the legitimacy of policies and regulations based on the extent to which they reflect the values of ordinary citizens whose lives will potentially be affected by these technologies. </p>
<p>Beyond its impact on regulation, however, this democratic experiment can show the way on how citizens, scientists, and policymakers can talk about a fast-moving technology with more care, better information, and democratic deliberation.</p><img src="https://counter.theconversation.com/content/146398/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicole Curato receives funding from the Australian Research Council for project titled Global Citizen Deliberation: Analysing a Deliberative Documentary.</span></em></p><p class="fine-print"><em><span>Simon Niemeyer receives funding from the Australian Research Council for project titled Global Citizen Deliberation: Analysing a Deliberative Documentary.</span></em></p>Our approach to controversial technologies shouldn’t be guided by scientists alone, nor by peddlers of misinformation on social media. A citizens’ assembly could walk the line between the two.Nicole Curato, Associate Professor, Centre for Deliberative Democracy and Global Governance, University of CanberraSimon Niemeyer, Professor in Deliberative Democracy and Environmental Governance, University of CanberraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1138272019-03-20T10:32:43Z2019-03-20T10:32:43ZA case against a moratorium on germline gene editing<figure><img src="https://images.theconversation.com/files/264849/original/file-20190320-93054-isf374.jpg?ixlib=rb-1.1.0&rect=132%2C0%2C5065%2C3509&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What's the best way to put the brakes on current research?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/embryologist-adding-sperm-egg-laboratory-reproductive-607661843">Okrasyuk/Shutterstock.com</a></span></figcaption></figure><p>Should researchers put the brakes on genetically engineering babies? Leading scientists and ethicists recently <a href="https://doi.org/10.1038/d41586-019-00726-5">called for a moratorium</a> on clinical applications of <a href="https://theconversation.com/editing-genes-shouldnt-be-too-scary-unless-they-are-the-ones-that-get-passed-to-future-generations-113627">germline gene editing</a>: inheritable alterations to the DNA of embryos to improve kids’ health or other features – or just “gene editing,” for short. </p>
<p>This declaration was prompted in part by the birth last year of the <a href="https://www.apnews.com/4997bb7aa36c45449b488e19ac83e86d">first gene-edited babies</a> in China. The birth was <a href="https://www.nature.com/articles/d41586-018-07545-0">roundly condemned</a> by experts and <a href="https://www.scmp.com/news/china/science/article/2182964/china-confirms-gene-edited-babies-blames-scientist-he-jiankui">may result</a> in charges against He Jiankui, the <a href="https://theconversation.com/us/topics/he-jiankui-63070">lead scientist involved</a>. </p>
<p>The call for a moratorium is grounded in two main concerns. Its supporters assert, first, that the risks of gene editing are simply too uncertain and potentially large to proceed. Secondly, the deeply controversial nature and potential social impact of altering human DNA means researchers need “<a href="http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=12032015a">broad societal consensus</a>” before proceeding.</p>
<p>The authors suggest a five-year pause to wait for more scientific progress and public dialogue. At that point, the authors propose, societies may choose to begin a path forward for gene editing, if risks are deemed acceptable and the process is fully transparent.</p>
<p>However, several scientists have <a href="https://www.statnews.com/2019/03/13/crispr-babies-germline-editing-moratorium/">pushed back</a> against the call for a moratorium, including gene-editing pioneer Jennifer Doudna and geneticist George Church. <a href="https://scholar.google.com/citations?user=yebS-LIAAAAJ&hl=en&oi=ao">As a biomedical ethicist</a>, I believe the objectors raise valid concerns about the relevance and usefulness of a moratorium that are worth reflecting upon.</p>
<h2>Plenty everyone agrees on</h2>
<p>To be sure, those for and against a moratorium actually agree on some key points.</p>
<p>Almost no one thinks the world is ready for clinical trials today, as more basic science is needed to minimize <a href="https://cosmosmagazine.com/biology/study-raises-fears-of-collateral-damage-in-gene-editing">risks like</a> editing the wrong bits of DNA, or “mosaicism,” where some but not all DNA in an embryo is altered. He Jiankui’s rogue science was <a href="https://theconversation.com/rogue-science-strikes-again-the-case-of-the-first-gene-edited-babies-107684">clearly unethical</a> for this and other reasons, including a lack of transparency and flaws in informed consent.</p>
<p>There is also no pushback against the idea that the world needs to have a <a href="https://doi.org/10.1038/d41586-018-03270-w">public conversation</a> about gene editing. Do you want to live in a society where embryos’ DNA is edited in order to improve the lives of the next generation? Are the risks of gene editing worth the benefits? Can and should we draw a bright line between editing for disease prevention and editing for enhancement? These questions cannot be answered only by experts, and require substantial public engagement.</p>
<p>Nevertheless, a divide over other issues remains.</p>
<p><iframe id="hAGmJ" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/hAGmJ/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Moratorium redundant where laws already exist</h2>
<p>Already, <a href="https://doi.org/10.1186/1477-7827-12-108">over 30 countries</a> prohibit this sort of gene editing, either by <a href="https://doi.org/10.1126/science.aad6778">law, regulation or enforceable guidelines</a>. For this reason, it was quite easy for the director of the U.S. National Institutes of Health to <a href="https://www.nih.gov/about-nih/who-we-are/nih-director/statements/nih-supports-international-moratorium-clinical-application-germline-editing">endorse the proposed moratorium</a> – the NIH, the <a href="https://www.nih.gov/about-nih/what-we-do/impact-nih-research/our-society">largest public funder of biomedical research in the world</a>, is already prohibited by law from funding clinical applications of gene editing. So a moratorium is at best redundant in those nations, perpetuating the status quo. </p>
<p>It is also liable to cause confusion. If a country or scientific body announces a moratorium as recommended, this could misleadingly imply that germline editing was previously permitted and unregulated. It could also suggest that some countries’ bans will expire in five years, when currently none has a time-limited prohibition.</p>
<h2>Arbitrariness of a blunt instrument</h2>
<p>At the same time, I believe a moratorium could work in countries that currently lack prohibitions on gene editing. It could help prevent rogue scientists from seeking environments that are relatively unregulated to pursue dubious experiments. <a href="https://www.technologyreview.com/s/602499/a-three-parent-child-was-conceived-in-mexico-because-the-us-wont-allow-it/">This is what happened</a> with the first births using mitochondrial replacement (so-called “3-parent IVF”): An American fertility doctor carried out part of the procedure in Mexico because he perceived the rules as laxer there.</p>
<p>Additionally, the call can be heard as an argument for reform of current laws and regulations: Society should revisit prohibitions and – depending on the evidence and popular opinion – consider rescinding them in five years’ time.</p>
<p>But <a href="https://edition.cnn.com/2019/03/13/health/inherited-dna-editing-moratorium-study/index.html">some researchers remain concerned</a> that a moratorium is an overly crude and arbitrary means of regulating a controversial new technology. While the technology is currently not fit for clinical use, are scientists so certain that it still won’t be within five years’ time? More flexible regulatory frameworks that do not include arbitrary timelines could better adapt to rapid scientific developments and shifts in public perceptions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/264851/original/file-20190320-93051-7po435.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In deciding how society should proceed on this front, members of the public have just as much say as experts.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/closeup-on-discussion-people-communicating-while-439213456">g-stockstudio/Shutterstock.com</a></span>
</figcaption>
</figure>
<h2>A call for public input – without public input</h2>
<p>Finally, it’s unclear whether a moratorium is consistent with the democratic norms that the proponents of a moratorium espouse. In particular, they reiterate the idea that researchers should only proceed with germline gene editing <a href="https://issues.org/on-human-gene-editing-international-summit-statement-by-the-organizing-committee/">if there is broad societal consensus</a> on how to proceed.</p>
<p>But shouldn’t a moratorium itself be subject to the requirement of broad societal consensus? Blanket prohibitions will have a substantial impact not just on the scientific community but on access for the rest of society to the potential fruits of research – a potential infringement of the <a href="https://unesdoc.unesco.org/ark:/48223/pf0000185558">human right to benefit from science</a>. Whether that infringement is justified is an important question that cannot be answered by experts alone.</p>
<p>To some extent, democratic countries that ban gene editing will have already undergone typical (if flawed) democratic processes to come to that decision. But in places that the moratorium is not redundant, it is reasonable to demand broad societal consensus before proceeding with a moratorium that even leading scientists don’t all agree on.</p>
<p>The cautious may argue that a presumption against gene editing is warranted before consensus can be established, because of the <a href="https://www.thehastingscenter.org/a-moratorium-on-gene-editing/">substantial individual risks</a> and <a href="https://www.nature.com/articles/s41431-017-0024-z">societal impact</a> of proceeding to alter the human genome for future generations. However, those societal risks are very substantial only if gene editing quickly becomes widespread. That is something careful regulation rather than a blanket prohibition might be well-suited to address. </p>
<p>In addition, I see it as somewhat problematic for experts to impose their own personal assessment of whether the risks outweigh the benefits of gene editing on the rest of society. Weighing risks and benefits is a fundamentally ethical issue, not one where scientific expertise can resolve the matter.</p>
<p>In the end, though, there seems to be broad agreement on the need for greater public deliberation over the questions related to germline gene editing: on whether gene editing is permissible, on whether a moratorium is appropriate – and more fundamentally, on what sort of a society we all want to live in.</p><img src="https://counter.theconversation.com/content/113827/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>G. Owen Schaefer does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Scientists and ethicists have called for a five-year moratorium on editing human genes that will pass on to future generations. Yes, society needs to figure out how to proceed – but is this the best way?G. Owen Schaefer, Research Assistant Professor in Biomedical Ethics, National University of SingaporeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1111272019-03-11T11:10:24Z2019-03-11T11:10:24ZAncient DNA is a powerful tool for studying the past – when archaeologists and geneticists work together<figure><img src="https://images.theconversation.com/files/262741/original/file-20190307-82665-lgyfm0.jpg?ixlib=rb-1.1.0&rect=7%2C516%2C2437%2C1693&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">New technology means accessing new information from ancient human remains, some which have been in collections for decades.</span> <span class="attribution"><span class="source">Duckworth Laboratory</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>DNA has moved beyond esoteric science and into the center of everyday conversations about identity, culture and politics. It’s also reshaping stories about the past as advances allow scientists to extract ancient DNA (aDNA) from skeletons found at archaeological sites. </p>
<p>With each ancient genetic sequence, scientists learn new information about how people moved around and interacted in the ancient world. In some cases, this has helped overturn theories and <a href="https://www.forbes.com/sites/jenniferraff/2018/12/27/five-amazing-things-we-learned-about-history-from-ancient-dna-in-2018/#7d3ab0cc11f7">resolve age-old debates</a>.</p>
<p>But the aDNA “revolution” has also caused friction among geneticists, archaeologists and others over how this research is done. <a href="https://scholar.google.com/citations?user=GlrnQDgAAAAJ&hl=en&oi=ao">As archaeologists</a> <a href="https://scholar.google.com/citations?user=3QKcZMoAAAAJ&hl=en&oi=sra">who collaborate</a> on aDNA projects, we’ve witnessed these tensions firsthand. What lies at the heart of this rift, and how can these disciplines work together to better research humanity’s past? </p>
<iframe title="Chart: How many ancient genomes have been sequenced?" aria-describedby="In the decade since researchers began sequencing ancient DNA, the number of archaic hominin and ancient human individuals sequenced has grown. The pace continues to increase, with almost 700 genomes sequenced just in the first three months of 2018." id="datawrapper-chart-7sEtu" src="https://datawrapper.dwcdn.net/7sEtu/1/" scrolling="no" frameborder="0" style="width: 0; min-width: 100% !important;" height="400" width="100%"></iframe>
<h2>What’s behind the aDNA revolution?</h2>
<p>Ancient DNA changes how scientists do research, rather than the questions being asked. Geneticists are working on the same problems that archaeologists, anthropologists and linguists have wrestled with for decades, aimed at understanding transitions in the past and the roots of the modern world.</p>
<p>But instead of looking at things people left behind, geneticists are interested in the people themselves. Skeletons are the only direct connection to individuals who experienced life in the past. Biological anthropologists have long studied <a href="https://www.forbes.com/sites/kristinakillgrove/2018/12/31/the-7-most-fascinating-skeletons-of-2018/#7df75d9d2510">bones and teeth</a> looking for clues about people’s origins and lives. Now, geneticists can look at their DNA – providing a new level of detail and insight.</p>
<p>The science behind aDNA is relatively new. The first fully sequenced <a href="https://doi.org/10.1038/nature08835">ancient human genome</a> – from a man who lived about 4,000 years ago in Greenland – was published only in 2010. At first this research was limited to skeletons from cold climates where DNA molecules are more likely to preserve. Success rates have steadily improved with cheaper and more efficient laboratory techniques and methods that target the most informative parts of the genome.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=541&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=541&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262476/original/file-20190306-100799-qrwwrj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=541&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The part of the skull that houses the inner ear, called the petrous portion, has proven to be a particularly good source of aDNA.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:708_Temporal_Bone.jpg">OpenStax College</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>One of the most important breakthroughs has been the discovery that a small part of the skull – the bony casing around the inner ear known as the petrous – is a <a href="https://biobeat.nigms.nih.gov/2018/04/the-skulls-petrous-bone-and-the-rise-of-ancient-human-dna-q-a-with-genetic-archaeologist-david-reich/">rich source of aDNA</a>, even in poorly preserved skeletons from hot climates. This finding has led to a massive increase in the pace and scale of aDNA studies, with <a href="https://media.nature.com/w800/magazine-assets/d41586-018-03773-6/d41586-018-03773-6_15565594.jpg">thousands of individuals</a> sequenced in 2018 alone and sudden widespread interest in archaeological skeletons in museums throughout the world.</p>
<p>aDNA has thrust archaeologists and geneticists into new partnerships, where one side provides archaeological samples and questions, and the other additional questions, specialized labs and funding. These specialists, with different training and distinct work cultures, don’t always see eye to eye on study design, research pace or interpretation of results. Additionally, institutions and countries may not have explicit aDNA policies in place, leaving research teams and museum curators to navigate research and sampling protocols on a case by case basis. <a href="https://theconversation.com/ancient-dna-unearths-fascinating-secrets-but-what-about-the-ethics-85186">This has elicited concern</a> from archaeologists, some of whom may worry the cart is so far beyond the horse that we should just cancel the trip.</p>
<p>But like <a href="https://www.world-archaeology.com/great-discoveries/radiocarbon-revolution/">radiocarbon dating</a> in the 20th century, aDNA has already fundamentally changed archaeology and will only become more prevalent. Understanding current misgivings now is the best way to move the science forward in a way that benefits everyone.</p>
<p>Critiques of aDNA can be grouped into three categories: interpretive, ethical and systemic.</p>
<h2>1) Interpreting the stories told by aDNA</h2>
<p>Many concerns focus on how aDNA results are used to answer questions about the past. Most aDNA studies come from <a href="https://en.wikipedia.org/wiki/Population_genetics">population genetics</a>, a subfield that looks at major demographic changes over time – usually attributed to people moving or mixing with other groups, or both.</p>
<p>But identifying these processes doesn’t tell researchers why they happened or detect their impacts on culture. Some critics suggest geneticists construct sweeping regional narratives about migration and population change based on a <a href="https://doi.org/10.1016/j.gde.2018.07.007">small number of skeletal samples</a>. Others point out that this research relies on <a href="https://doi.org/10.1038/s41598-018-31123-z">naming and grouping ancient peoples based on cultural evidence</a> like pottery styles, which may or may not <a href="https://doi.org/10.1126/science.aan0737">reflect biological relatedness</a>. Ancient genetic sequences are also usually compared to modern ones from living people, who have their own <a href="https://doi.org/10.1086/300144">complicated histories</a> and are grouped based on language or ethnicity or both at the time of DNA sampling, making for potentially problematic comparisons.</p>
<p>Ultimately, interpreting aDNA results involves many of the same archaeologically informed assumptions as other studies of bones, pots and tools. Yet the scientific aura of aDNA means findings are presented to the world through the media as more objective, stoking archaeologists’ frustrations over apparent “<a href="https://doi.org/10.1038/d41586-018-03773-6">molecular chauvinism</a>.”</p>
<h2>2) Balancing ethical obligations</h2>
<p><a href="https://theconversation.com/rights-of-the-dead-and-the-living-clash-when-scientists-extract-dna-from-human-remains-94284">Ethical issues with aDNA</a> affect both the living and the dead. In order to extract sequences, archaeological human remains must be ground up under special sterile conditions. Some targeted parts of the body – like petrous bones and teeth – provide <a href="https://doi.org/10.1073/pnas.1717873115">valuable information</a> about our species’ evolution and history. Since there’s not an infinite supply of archaeological bones, many scholars are <a href="https://doi.org/10.1038/nature.2017.22445">calling for regulations</a> to protect skeletal collections and ensure that future researchers can access them.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262743/original/file-20190307-82661-1bh2q31.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ancient DNA research must be balanced with preserving museum collections for future generations.</span>
<span class="attribution"><span class="source">Elizabeth Sawchuk at the National Museums of Kenya</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Today’s scientists must also contend with past colonial practices that <a href="https://theconversation.com/returning-looted-artefacts-will-finally-restore-heritage-to-the-brilliant-cultures-that-made-them-107479">removed skeletons and artifacts</a> from their countries of origin and sent them to Europe and North America, raising questions about who should now give permission for their study. </p>
<p>Beyond the destruction of ancestors, aDNA findings can pose other harm to indigenous peoples. Because most aDNA studies have focused on skeletons excavated decades ago, few explicitly mention <a href="https://www.sapiens.org/archaeology/chaco-canyon-nagpra/">consultation with descendant groups</a>. However, aDNA studies can have <a href="https://doi.org/10.1126/science.aaq1131">negative consequences</a> for these communities. They can complicate land claims and repatriation efforts, undermine oral histories and reveal stigmatizing information like genetic susceptibility to disease. Findings about the past have present-day political implications depending on how they are <a href="http://onlinedigeditions.com/publication/?i=563489&article_id=3292127&view=articleBrowser&ver=html5#%7B%22issue_id%22:563489,%22view%22:%22articleBrowser%22,%22article_id%22:%223292127%22%7D">received and mobilized</a>.</p>
<h2>3) Designing a new science</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=708&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=708&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=708&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=890&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=890&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262742/original/file-20190307-82652-117a21b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=890&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Archaeologists play a key role in aDNA research, selecting samples from excavations and museum collections and providing their own interpretations.</span>
<span class="attribution"><span class="source">Steven Goldstein</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Underlying all these concerns are apprehensions about how archaeogenetics is developing as a field. <a href="https://www.nytimes.com/2019/01/17/magazine/ancient-dna-paleogenomics.html">A recent article</a> in the popular press painted a dramatic picture of a high stakes game in which a handful of labs dominate access to samples and groundbreaking discoveries. Archaeologists are portrayed as fearful or helpless, exchanging samples for a minor authorship role without the ability to offer their own interpretations. But this hardly describes all archaeologists, many of whom occupy prominent positions on aDNA projects.</p>
<p>Yes, competition for samples can factor into the fast pace of research and exacerbate some of the issues around aDNA. It is wrong though, to place blame on labs alone. An entire system comprising universities, scientific journals, funding bodies and the media stands ready to reward the next big discovery. Pointing the finger at individuals or labs only fosters division, pushing people away from aDNA research without addressing issues or finding solutions.</p>
<h2>Mapping out the future of aDNA</h2>
<p>Fortunately, change is already happening.</p>
<p>Responses to the first wave of aDNA studies called for better integration of archaeological and genetic data and more nuanced questions about smaller-scale cultural and population shifts. Such change may end up occurring organically as the bar for publication shifts away from <a href="https://doi.org/10.1126/science.aad2879">single sequences</a> to <a href="https://doi.org/10.1038/nature25738">studies of hundreds of individuals</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=209&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=209&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=209&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=263&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=263&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262565/original/file-20190306-100778-axh4cu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=263&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">aDNA sequences are shedding light on previously understudied areas, like the Rift Valley in Tanzania.</span>
<span class="attribution"><span class="source">Mary Prendergast</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Strict standards require genomic data to be made public, and aDNA research has become a <a href="https://doi.org/10.1371/journal.pone.0121409">model for the open science movement</a>. This means more comparative data will become available over time to tackle fine-grained questions about regional histories. As aDNA is brought to bear on increasingly complex questions, archaeologists will need to take on more equitable roles in research design, interpretation and integration of multiple types of evidence.</p>
<p>The field is also making headway on ethical issues. <a href="https://doi.org/10.1016/j.cell.2018.10.027">Ethics statements</a> are appearing in journal articles. <a href="https://doi.org/10.1073/pnas.1822038116">Museums are establishing their own guidelines</a>. Archaeologists have stepped forward to suggest <a href="https://doi.org/10.15184/aqy.2018.70">best practices for sampling</a> and <a href="https://doi.org/10.1126/science.aaq1131">consulting with indigenous stakeholders</a>.</p>
<p>There has also been a push for <a href="http://onlinedigeditions.com/publication/?i=563489">better communication and outreach</a>. The <a href="https://sing.igb.illinois.edu">Summer internship for INdigenous peoples in Genomics</a> (SING) is designed to help dismantle barriers between descendant communities and scientists. aDNA sessions and <a href="http://blogs.brown.edu/archaeology/workshops/sotf2019/">entire conferences</a> bringing geneticists and archaeologists together are becoming more common. Establishing discipline-wide best practices and support through professional networks will reduce the burden on individuals to ensure research is done the right way.</p>
<p>Communication and cooperation go a long way, but fixing the system ultimately requires a shift in how science is funded and rewarded. And the public has a key role to play as the taxpayers who fund scientific research and consume its findings. A scientifically literate society can demand work that meets ethical guidelines and provides meaningful insights about our past. Together, scientists and the public can set the tone for what aDNA research becomes and how we use it to explore our shared human heritage.</p><img src="https://counter.theconversation.com/content/111127/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Ancient DNA allows scientists to learn directly from the remains of people from the past. As this new field takes off, researchers are figuring out how to ethically work with ancient samples and each other.Elizabeth Sawchuk, Postdoctoral Fellow and Research Assistant Professor of Anthropology, Stony Brook University (The State University of New York)Mary Prendergast, Professor of Anthropology, Saint Louis University – MadridLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/965742018-05-25T12:22:24Z2018-05-25T12:22:24ZWe’re not prepared for the genetic revolution that’s coming<figure><img src="https://images.theconversation.com/files/220458/original/file-20180525-51135-qvxam5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/close-businessman-holding-glowing-dna-helix-683382997?src=XtIrmtlLbNh-UD32uwMXmQ-1-6">Shutterstock</a></span></figcaption></figure><p>When humans’ genetic information (known as the genome) was mapped 15 years ago, it promised to change the world. Optimists anticipated an era in which all genetic diseases would be eradicated. Pessimists feared widespread genetic discrimination. Neither of these hopes and fears have been realised.</p>
<p>The reason for this is simple: our genome is complex. Being able to locate specific differences in the genome is only a very small part of understanding how these genetic variants actually work to produce the traits we see. Unfortunately, few people understand just how complex genetics really is. And as more and more products and services start to use genetic data, there’s a danger that this lack of understanding could lead people to make some very bad decisions.</p>
<p>At school we are taught that there is a dominant gene for brown eyes and a recessive one for blue. In reality, there are almost no human traits that are passed from generation to generation in such a straightforward way. Most traits, <a href="https://www.nature.com/articles/jhg2010126">eye colour</a> included, develop under the influence of several genes, each with its own small effect.</p>
<p>What’s more, each gene contributes to many different traits, a concept called pleiotropy. For example, genetic variants associated with autism have also been <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4511766/">linked with schizophrenia</a>. When a gene relates to one trait in a positive way (producing a healthy heart, say) but another in a negative way (perhaps increasing the risk of macular degeneration in the eye), it is known as <a href="https://www.nature.com/articles/ncomms7063">antagonistic pleiotropy</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/220460/original/file-20180525-51102-1ymb73h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220460/original/file-20180525-51102-1ymb73h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=342&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220460/original/file-20180525-51102-1ymb73h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=342&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220460/original/file-20180525-51102-1ymb73h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=342&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220460/original/file-20180525-51102-1ymb73h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=430&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220460/original/file-20180525-51102-1ymb73h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=430&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220460/original/file-20180525-51102-1ymb73h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=430&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">There’s no single gene for eye colour.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/closeup-blue-eyes-woman-without-makeup-326171174?src=FdLfJZAe9ecP0M7kAff_bg-1-42">Shutterstock</a></span>
</figcaption>
</figure>
<p>As computing power has increased, scientists have been able to link many individual molecular differences in DNA with specific human characteristics, including behavioural traits such as <a href="https://www.nature.com/articles/mp2016107">educational attainment</a> and <a href="https://www.biologicalpsychiatryjournal.com/article/S0006-3223(16)32664-6/fulltext">psychopathy</a>. Each of these genetic variants only explains a tiny amount of variation in a population. But when all these variants are summed together (giving what’s known as a characteristic’s <a href="https://blogs.scientificamerican.com/guest-blog/whats-your-polygenic-score/">polygenic score</a>) they begin to explain more and more of the differences we see in the people around us. And with a lack of genetic knowledge, that’s where things start to be misunderstood.</p>
<p>For example, we could sequence the DNA of a newborn child, calculate their polygenic score for academic achievement and use it to predict, with some degree of accuracy, how well they will do in school. Genetic information may be the strongest and most precise predictor of a child’s <a href="https://www.nature.com/articles/mp2016107">strengths and weaknesses</a>. Using genetic data could allow us to more effectively personalise education and target resources to those children most in need.</p>
<p>But this would only work if parents, teachers and policymakers have enough understanding of genetics to correctly use the information. <a href="https://www.cambridge.org/core/journals/journal-of-biosocial-science/article/genes-and-gini-what-inequality-means-for-heritability/FD7C2DEA0A89346708A193B5CB23B0CF">Genetic effects can be prevented or enhanced</a> by changing a person’s environment, including by providing educational opportunity and choice. The misplaced view that genetic influences are fixed could lead to a system in which children are permanently separated into grades based on their DNA and not given the right support for their actual abilities.</p>
<h2>Better medical knowledge</h2>
<p>In a medical context, people are likely to be given advice and guidance about genetics by a doctor or other professional. But even with such help, people who have better genetic knowledge will benefit more and will be able to make more informed decisions about their own health, family planning, and health of their relatives. People are already confronted with offers to undergo costly genetic testing and gene-based <a href="https://www.oncologica.com/dynamic-cmp-routing/?pg=sp6&vn=dbs&cmp=adw&lng=en&ch=google&gclid=EAIaIQobChMIxpb5gN7u2gIVxITVCh04BgSSEAAYASAAEgIxn_D_BwE">treatments for cancer</a>. Understanding genetics could help them avoid pursuing treatments that aren’t actually suitable in their case.</p>
<p>It is now possible to edit the human genome directly using a technique called <a href="https://theconversation.com/what-is-crispr-gene-editing-and-how-does-it-work-84591">CRISPR</a>. Even though such genetic modification techniques are regulated, the relative simplicity of CRISPR means that biohackers are already using it to edit their own genomes, for example, to <a href="https://www.buzzfeed.com/stephaniemlee/this-biohacker-wants-to-edit-his-own-dna?utm_term=.jjYRlLwxmA#.tsqoROD5xA">enhance muscle tissue</a> or <a href="http://www.bbc.co.uk/news/world-us-canada-41990981">treat HIV</a>.</p>
<p>Such biohacking services are very likely to be made available to buy (even if illegally). But as we know from our explanation of pleiotropy, changing one gene in a positive way could also have catastrophic unintended consequences. Even a broad understanding of this could save would-be biohackers from making a very costly and even potentially fatal mistake. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/220461/original/file-20180525-51121-gocrpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220461/original/file-20180525-51121-gocrpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220461/original/file-20180525-51121-gocrpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220461/original/file-20180525-51121-gocrpk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220461/original/file-20180525-51121-gocrpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=454&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220461/original/file-20180525-51121-gocrpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=454&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220461/original/file-20180525-51121-gocrpk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=454&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Biohackers may try to enhance their bodies with altered DNA.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/heroin-addiction-young-manteen-finding-vein-88931419?src=gdauW8rYfTzlMoSTuISRDA-1-39">Shutterstock</a></span>
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<p>When we don’t have medical professionals to guide us, we become even more vulnerable to potential genetic misinformation. For example, <a href="https://www.marmite.co.uk/geneproject">Marmite</a> recently ran an ad campaign offering a genetic test to see if you either love or hate Marmite, at a cost of £89.99. While witty and whimsical, this campaign also has several problems.</p>
<p>First, Marmite preference, just like any complex trait, is influenced by complex interactions between genes and environments and is far from determined at birth. At best, a test like this can only say that you are more likely to like Marmite, and it will have a great deal of error in that prediction.</p>
<p>Second, the ad campaign shows a young man seemingly <a href="https://www.youtube.com/watch?v=AjivUDIawLI">“coming out”</a> to his father as a Marmite lover. This apparent analogy to sexual orientation could arguably perpetuate the outdated and dangerous notion of “<a href="https://theconversation.com/gay-genetics-research-still-causes-irrational-fears-23284">the gay gene</a>”, or indeed the idea that there is any single gene for complex traits. Having a good level of genetic knowledge will enable people to better question advertising and media campaigns, and potentially save them from wasting their money.</p>
<p><a href="https://link.springer.com/article/10.1007/s12687-018-0363-7">My own research</a> has shown that even the well-educated amongst us have poor genetic knowledge. People are not empowered to make informed decisions or to engage in fair and productive public discussions and to make their voices heard. Accurate information about genetics needs to be widely available and more routinely taught. In particular, it needs to be incorporated into the training of teachers, lawyers and health care professionals who will very soon be faced with genetic information in their day-to-day work.</p>
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<p><em>To test your genetic knowledge and see how ready you are to make informed decisions in the genomic era visit <a href="http://www.tagc.world/iglas">The International Genetics Literacy and Attitudes Survey</a> and contribute to our ongoing research.</em></p><img src="https://counter.theconversation.com/content/96574/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Chapman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Genetics is influencing more and more of our decisions, but we can’t make the right choices if we don’t understand it.Robert Chapman, PhD Candidate, Goldsmiths, University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/959192018-05-03T20:21:03Z2018-05-03T20:21:03ZThe Dreamtime, science and narratives of Indigenous Australia<figure><img src="https://images.theconversation.com/files/217130/original/file-20180501-135803-tkypa4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lake Mungo and the surrounding Willandra Lakes of NSW were established around 150,000 years ago. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sunset-over-famous-walls-china-mungo-580536352?src=BM3RK99LNXsfkXUcrXCK0Q-1-0">from www.shutterstock.com </a></span></figcaption></figure><p><em>This article is an extract from an essay <strong>Owning the science: the power of partnerships</strong> in <a href="https://griffithreview.com/editions/first-things-first/">First Things First</a>, the 60th edition of Griffith Review.</em></p>
<p><em>We’re publishing it as part of our occasional series Zoom Out, where authors explore key ideas in science and technology in the broader context of society and humanity.</em></p>
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<p>Scientific and Indigenous knowledge systems have often been in conflict. In my view, too much is made of these conflicts; they have a lot in common.</p>
<p>For example, Indigenous knowledge typically takes the form of a narrative, usually a spoken story about how the world came to be. In a similar way, evolutionary theories, which aim to explain why particular characters are adapted to certain functions, also take the form of narratives. Both narratives are mostly focused on “origins”.</p>
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Read more:
<a href="https://theconversation.com/friday-essay-when-did-australias-human-history-begin-87251">Friday essay: when did Australia’s human history begin?</a>
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<p>From a strictly genetic perspective, progress on origins research in Australia has been particularly slow. Early ancient DNA studies were focused on remains from permafrost conditions in Antarctica and cool temperate environments such as northern Europe, including Greenland.</p>
<p>But Australia is very different. Here, human remains are very old, and many are recovered from very hot environments.</p>
<p>While ancient DNA studies have played an important role in informing understanding of the evolution of our species worldwide, little is known about the levels of ancient genomic variation in Australia’s First Peoples – although some progress has been made in recent years. This includes the landmark recovery of genomic sequences from both contemporary and ancient Aboriginal Australian remains.</p>
<h2>Found, or revealed?</h2>
<p><a href="http://www.visitmungo.com.au/who-was-mungo-lady">Mungo Man and Mungo Lady</a> have been the subject of both Indigenous and scientific narratives.</p>
<p>From a scientific perspective, in 1968 the burnt remains of a woman were recovered at Lake Mungo by Jim Bowler, a young geologist. Six years later, after heavy rain, Bowler was riding his motorbike around the lake and again found human remains, this time of a man.</p>
<p>From an Indigenous perspective, it was not that Jim Bowler discovered these ancient people but that they found him. And of course, one is struck by the apparent coincidence that they both revealed themselves to the same person, albeit six years apart.</p>
<p>Professor <a href="https://theconversation.com/profiles/jim-bowler-145173">Jim Bowler</a> is a distinguished scientist who has close ties with, and an understanding of, Australia’s First Peoples, so Mungo Lady and Mungo Man chose well.</p>
<h2>Since the Dreamtime</h2>
<p>Perhaps the most well-known conflict between scientific and Indigenous perspectives relates to the origins of Aboriginal Australians.</p>
<p>From an Indigenous perspective, Aboriginal Australians have always been on this land – since the Dreamtime. From a scientific perspective, there is strong evidence that they have been here for more than 65,000 years – not quite “always”.</p>
<p>From my perspective, though, 65,000 years seems pretty close to “always”, and, moreover, it is likely that people became Aboriginal Australians when they first set foot on this land. So, in this sense, they have indeed always been here.</p>
<p>When a <a href="http://www.pnas.org/content/98/2/537">publication by Professor Alan Thorne</a>, a prominent Australian anthropologist, and his colleagues from the Australian National University appeared in the journal PNAS in 2001, it drew worldwide attention. The authors reported the recovery of short <a href="https://ghr.nlm.nih.gov/primer/basics/mtdna">mitochondrial DNA</a> from Mungo Man, as well as the other ancient remains of a number of people from the Willandra Lakes region.</p>
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Read more:
<a href="https://theconversation.com/explainer-what-are-mitochondria-and-how-did-we-come-to-have-them-83106">Explainer: what are mitochondria and how did we come to have them?</a>
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<p>The results from their analysis, which included an evolutionary tree of recovered DNA sequences, suggested that Mungo Man was genetically different to the other ancient people they studied, who were closely related to the Aboriginal Australians of today.</p>
<p>This implied that contemporary Aboriginal Australians replaced another population of humans that lived here first.</p>
<p>This conclusion caused widespread offence among Aboriginal people, though it was difficult for them to reject the scientific claims. Some <a href="http://www.abc.net.au/science/articles/2001/01/01/2813404.htm">scientists argued</a> that Thorne’s results were highly unlikely to be correct, given the age of the remains and the hot environment in which they had been interred. It was not, however, possible to refute these claims without a detailed understanding of the methods used and the opportunity to redo the experiment.</p>
<p>Some politicians and commentators seized on the result to <a href="https://theconversation.com/factcheck-might-there-have-been-people-in-australia-prior-to-aboriginal-people-43911">argue against constitutional recognition of Aboriginal Australians</a>, suggesting there was considerable doubt about their First Peoples status.</p>
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Read more:
<a href="https://theconversation.com/factcheck-might-there-have-been-people-in-australia-prior-to-aboriginal-people-43911">FactCheck: might there have been people in Australia prior to Aboriginal people?</a>
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<h2>Big personalities</h2>
<p>Big personalities have dominated Australian archaeology and anthropology, and influenced its development – Alan Thorne prominent among them. He first became involved in the Lake Mungo excavations under the archaeologist Jim Bowler in 1969, reconstructing the remains of the skeleton of Mungo Lady.</p>
<p>Five years later he also reconstructed Mungo Man and led excavations at other important burial grounds in Victoria. Thorne was very well known for his work on the multiregional evolution hypothesis, a model of human evolution that disputed the more widely known recent African origin (or “<a href="https://theconversation.com/worlds-scientists-turn-to-asia-and-australia-to-rewrite-human-history-88697">out of Africa</a>”) hypothesis.</p>
<p>For more than a decade after Thorne’s research was published, his work on Mungo Man and other ancient people from Willandra went largely unchallenged, despite the distress it caused to Aboriginal Australians.</p>
<p>Then, in 2010, with the permission of the Paakantji, Ngyiampaa and the Mutthi Mutthi peoples of the Willandra Lakes, my colleagues and I from the Australian Research Centre for Human Evolution were able to resample these important remains.</p>
<p>With the advantages of technology that had developed in the preceding decade, we repeated much of the original work. The new technology meant that we were able to recover much smaller amounts of DNA (if it was still present in the remains) and sequence it.</p>
<p>In 2016, we also <a href="http://www.pnas.org/content/113/25/6892">published the results</a> in PNAS journal. Our findings provided <a href="https://theconversation.com/new-dna-study-confirms-ancient-aborigines-were-the-first-australians-60616">strong evidence</a> to refute the claims made by Thorne and his colleagues, showing it was not possible to recover any DNA that unequivocally belonged to Mungo Man.</p>
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<strong>
Read more:
<a href="https://theconversation.com/new-dna-study-confirms-ancient-aborigines-were-the-first-australians-60616">New DNA study confirms ancient Aborigines were the First Australians</a>
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<p>We did, however, recover five distinct DNA sequences from his remains. But these sequences revealed no ancient DNA damage patterns, indicating that they were not ancient sequences – and genetic analysis showed that they were European in origin. Clearly these were sequences from people who left their DNA on the bone material after handling Mungo Man’s remains.</p>
<h2>New techniques, new light</h2>
<p>Our study set the record straight. We refuted the claim that Mungo Man was a member of an earlier group of people that previously inhabited Australia and not an Aboriginal Australian.</p>
<p>Perhaps of equal importance, we were able to recover substantial coverage of the mitochondrial genome from another ancient Willandra Lakes man, who was buried only a few hundred metres from Mungo Man.</p>
<p>The remains contained about 1% human DNA; from them, we were able to recover two complete mitochondrial genomes. One of these was a previously unidentified Aboriginal Australian mitochondrial genetic type, almost certainly from the remains themselves. The other was European in origin, and certainly a contaminant.</p>
<p>It appeared that this man was from within the Holocene period (that is, the period since the last Ice Age that ended around 11,700 years ago); we know this because the skeletal remains were not heavily mineralised. His teeth exhibited a pattern of wear typical of Aboriginal hunter-gatherer populations and included no evidence of cavities or tooth decay. </p>
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Read more:
<a href="https://theconversation.com/worlds-scientists-turn-to-asia-and-australia-to-rewrite-human-history-88697">World's scientists turn to Asia and Australia to rewrite human history</a>
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<p>Combined with the lack of mineralisation in the bone and its position in the soil layers at Lake Mungo, various authors have suggested that the remains were a few thousand years old. This is important, because it means that he represents the best “proxy” currently available for Mungo Man.</p>
<p>The fact that he was buried so close to the oldest-known Australian, albeit much later, suggests a common place and country. This is particularly significant given that the environmental conditions were very different at the times of the two burials, which were about 40,000 years apart.</p>
<p>Hence, nuclear gene studies of this man, currently underway, will be especially relevant to our understanding of Mungo Man himself. And because the nuclear genome is much larger than the mitochondrial, it will reveal much more information.</p>
<p>Such nuclear genome studies enable us to establish kinship relationships between people living now and ancient peoples. Such studies will take substantial time and effort, and will require the development of new innovative genomic tools.</p>
<p>Ethical considerations demand Aboriginal involvement in both the design and operation of such new techniques, as well as new research relationships with Indigenous communities.</p>
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Read more:
<a href="https://theconversation.com/buried-tools-and-pigments-tell-a-new-history-of-humans-in-australia-for-65-000-years-81021">Buried tools and pigments tell a new history of humans in Australia for 65,000 years</a>
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<img src="https://counter.theconversation.com/content/95919/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Lambert receives funding from the Australian Research Council.</span></em></p>New techniques for genetic analysis are helping us build more detailed and accurate stories about the ancient histories of the first Australians.David Lambert, Professor of Evolutionary Biology, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/927942018-03-22T10:42:06Z2018-03-22T10:42:06ZMitochondria mutation mystery solved: Random sorting helps get rid of duds<figure><img src="https://images.theconversation.com/files/211047/original/file-20180319-31633-1sxhx6g.jpg?ixlib=rb-1.1.0&rect=2%2C16%2C590%2C453&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When a cell divides, mitochondria are randomly allotted to the resulting new cells.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/wellcomeimages/25937295324">Odra Noel. Wellcome Images</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>You probably know about the 23 pairs of chromosomes safely stowed in your cells’ nuclei. That’s where the vast majority of your genes can be found. But there are 37 special genes — a very tiny fraction of the human genome — located in mitochondria, the structures inside your cells that breathe and produce energy.</p>
<p>Repeated copying of mitochondrial DNA introduces errors; if not kept in check, these mutations can give rise to incurable diseases like <a href="https://ghr.nlm.nih.gov/condition/leigh-syndrome">Leigh syndrome</a> and <a href="https://ghr.nlm.nih.gov/condition/leber-hereditary-optic-neuropathy">Leber’s optic neuropathy</a>. Worldwide, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4737121/">more than 1 in 10,000</a> people are affected by disorders resulting from mitochondrial genome defects.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=671&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=671&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=671&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=843&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=843&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211067/original/file-20180319-31614-14j8noq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=843&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Mitochondrial DNA is inherited only from the mother, based on what mitochondria happen to be in the egg.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Mitochondrial_DNA_lg.jpg">National Human Genome Research Institute</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Unlike nuclear chromosomes that we get from both parents, only mothers’ mitochondria are passed on to offspring. This makes the usual process of sexual recombination, in which pieces of maternal and paternal chromosomes combine to repair genome defects, impossible. For decades, biologists predicted that without this repair mechanism, mitochondrial genes should rapidly accumulate harmful mutations and <a href="http://rspb.royalsocietypublishing.org/content/early/2009/02/09/rspb.2008.1758.short">lose their function</a>.</p>
<p>Despite these predictions, mitochondrial disorders in humans, while debilitating, are relatively rare. A <a href="https://doi.org/10.1038/s41556-017-0017-8">set of experiments</a> with human embryos has recently found low levels of mitochondrial mutations in most of the studied cells, that, strikingly, were otherwise perfectly healthy. If mitochondrial defects are so common, what keeps them from reaching dangerous disease-causing levels?</p>
<h2>Dealing out mitochondria by chance</h2>
<p>A typical human cell contains hundreds of mitochondria. Each mitochondrion in turn has many genome copies jointly responsible for <a href="https://en.wikipedia.org/wiki/Cellular_respiration">energy production</a>. If only a few of these copies become faulty, the rest of the mitochondria can still produce enough energy, and the cell does perfectly fine. In fact, some of the most severe disorders develop only when <a href="https://doi.org/10.1111/dgd.12420">60 to 90 percent</a> of mitochondria within each cell become mutated. This means that low levels of mitochondrial mutations are essentially invisible, and can lurk within human cells for generations without causing a disease. </p>
<p>Recent <a href="https://doi.org/10.1534/genetics.117.300273">theoretical work</a> by <a href="https://scholar.google.com/citations?user=yi-SnYcAAAAJ&hl=en&oi=ao">me</a> and my colleagues predicted a number of solutions that likely evolved to expose and eventually eliminate these hidden defects. The general principle we proposed is based on simple sorting of healthy and faulty mitochondria.</p>
<p>Whenever a cell within a developing embryo divides, mitochondria are partitioned into the two daughter cells more or less randomly. By chance, one of the two daughter cells inherits more mitochondrial defects than the other. Initially, this difference is barely noticeable. But repeat the process many times and a sizeable proportion of all daughter cells will have enough mutations to ensure that the cell does not survive. </p>
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<a href="https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=277&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=277&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=277&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=348&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=348&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211432/original/file-20180321-165583-11ye0fl.PNG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=348&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The mitochondria make copies in preparation for a cell dividing. Which version winds up in each daughter cell is essentially random. By chance, the bottom cell has even fewer of the red version than the original cell.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1371/journal.pbio.2000410">Radzvilavicius et al</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>On the opposite side of the spectrum, this leaves cells that have fewer mutations even than the original cell that started dividing. This simple mechanism of cell division and random sorting of mitochondria can therefore produce cells packed with healthy mitochondria that can then go on to divide further and to eventually produce mutation-free reproductive cells (eggs in females).</p>
<p>But there’s more. Scientists now believe that many features of the human reproductive system evolved to increase the efficiency of this random mitochondrial sorting. For instance, mutations would pile up faster if both paternal and maternal mitochondria were inherited by the offspring – mixing of two unrelated types of organelles would make it easier for rare defects to hide. It is very likely that we inherit mitochondrial genes only from our mothers precisely because it slows down the accumulation of defective genes.</p>
<p>The number of genome replication cycles also matters, because new defects are introduced each time genes are copied. In a paper published in 2016, my colleagues and I suggest this <a href="https://doi.org/10.1371/journal.pbio.2000410">could be the reason</a> why the number of cell divisions to produce an egg in females is strictly limited to 24. In males – whose mitochondria are not transmitted to the offspring – sperm are produced continually with more than 400 cell divisions by the age of 30. By capping the number of times a cell divides before an egg is made, females reduce the risk of introducing new copying errors in their mitochondrial genes.</p>
<p>Likewise, theory predicts that random sorting of healthy and sickly mitochondria works best when the number of mitochondria in a cell is low. With only a few mitochondria, even slightly defective genes cannot hide; their harmful effects are immediately obvious at the level of the cell, which can then be eliminated.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211068/original/file-20180319-31596-p49o9j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Less hearty mitochondria may already be getting weeded out in an eight-cell embryo.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Embryo,_8_cells.jpg">eked</a></span>
</figcaption>
</figure>
<h2>Observing what theory predicts</h2>
<p>Confirming these predictions, a recent study involving human embryos has indeed discovered that the <a href="https://doi.org/10.1038/s41556-017-0017-8">number of mitochondria is sharply reduced throughout development</a> – from 1 million in a fertilized egg to only around 1,500 per cell in a 4-week-old embryo. Researchers also found that cells taken from older embryos had fewer mitochondrial mutations, meaning that cells with the most defects were somehow eliminated throughout embryonic development.</p>
<p>It is not yet clear how cells with the most mitochondrial mutations are selectively removed in human embryos. But because most of the harmful mutations were eliminated at the stage of embryonic development when cells start breathing more actively, scientists think that damaged mitochondria simply fail to produce enough energy for the cell to survive. </p>
<p>Many questions remain. For instance, why do cells with high levels of defective mitochondria sometimes escape these quality-control mechanisms, resulting in incurable disorders? Ultimately, greater understanding of these mechanisms should suggest better ways of estimating the risk of mitochondrial diseases, or even develop new interventions to prevent them completely.</p><img src="https://counter.theconversation.com/content/92794/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Arunas L. Radzvilavicius receives funding from Defense Advanced Research Projects Agency.</span></em></p>The genes in our cells’ mitochondria are passed on in a different way than the vast majority of our DNA. New studies shed light on how the unique process isn’t derailed by mutations.Arunas L. Radzvilavicius, Postdoctoral Researcher of Evolutionary Biology, University of PennsylvaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/902882018-01-25T23:14:51Z2018-01-25T23:14:51ZWhy aren’t you a lefty? A geneticist finds clues in kangaroos and shopping malls<p>In graduate school, I earned beer money by modelling for life drawing classes in various art departments. (Don’t judge, grad school doesn’t pay well and beer isn’t free.) In the long hours standing around, I would survey the room and count how many of the aspiring artists were left-handed. Later in my career, I did the same thing — counting lefties, not standing around naked — in the biology classes I taught. </p>
<p>Funny thing, in any given class, around 10 per cent of the students were lefties. It turns out this is true for all human populations, not only middle-America university classes. Globally, about 90 per cent of people are righties. But why?</p>
<p>For as long as I can remember, I’ve been fascinated by handedness — our almost ubiquitous tendency to favour one hand over the other — and maybe a little envious of the rare left-handers. Their rareness gave a certain mystique — and they got to use those funky <a href="http://dailybruin.com/2016/04/07/kuhelika-ghosh-left-handed-students-are-hindered-by-lack-of-accommodating-desks/">chair-desks</a> with the desktop on the “wrong” side. </p>
<p>What do we know about the genetics of being right- or left-handed, or even ambidextrous? And how does this help shape our understanding of biology in general?</p>
<h2>What is “handedness” anyway?</h2>
<p>Given how fundamental, and obvious, handedness is, we know surprisingly little about its genetics. </p>
<p>One complication — determining handedness isn’t straightforward. The dominance of your writing (and drawing) hand is a function of at least three things: Genetics to be sure, but also the environment, and, likely, random chance. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/202902/original/file-20180122-182965-1nd4u7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/202902/original/file-20180122-182965-1nd4u7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202902/original/file-20180122-182965-1nd4u7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202902/original/file-20180122-182965-1nd4u7a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202902/original/file-20180122-182965-1nd4u7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202902/original/file-20180122-182965-1nd4u7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202902/original/file-20180122-182965-1nd4u7a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Our environmental surroundings can pressure us to adopt certain behaviours, like handedness, even if we aren’t genetically wired that way.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Why the environment? Think of the probably-not-apocryphal stories of the Catholic school nuns ruler-rapping the knuckles of anyone so sinister to write with their left hand. (My father-in-law swears these stories are true.) </p>
<p>In many cultures, the left is associated with evil. There has been, and may continue to be, considerable pressure against maintaining the left hand as the dominant hand. </p>
<p>Less violently, but no less effectively, there is convenience. Try using a pair of right-handed scissors with your left hand. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/sy4d8lQ669g?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Why left-handers can’t use right-handed scissors.</span></figcaption>
</figure>
<p>That didn’t work, did it? </p>
<p>The fact that scissors, and other assorted manual tools and appliances, from <a href="https://www.buzzfeed.com/katienotopoulos/the-18-worst-things-for-left-handed-people?utm_term=.pa7voW3al#.dhrMA4yEw">dessert forks to chainsaws</a>, are designed for the righty majority means they’re harder to use lefty, resulting in considerable pressure to conform and use your right hand. </p>
<h2>What does “right-handed” really mean?</h2>
<p>This pressure means that many studies that defined handedness by identifying the dominant hand in writing may have miscategorized a substantial portion of the population. </p>
<p>A solution adopted by many researchers is to assay a suite of behaviours. There are a surprising number of activities that show a dominant hand, including the <a href="https://www.vice.com/en_nz/article/xdmxbq/ask-expert-left-handed-masturbation">decidedly adult behaviour</a> that may have just crossed your mind, but also more demure pastimes like sewing or spoon use. </p>
<p>A twist, which becomes important when we look at the genetics, is that researchers can classify people into one of three groups — right- or left-handed or ambidextrous — or two groups — right-handed and not right-handed. </p>
<p>Genetics definitely plays a role, but what kind of role? Is the genetics of handedness deterministic, essentially a right/left switch, or is it more subtle?</p>
<p>Could there be a genetic makeup, or genotype, that predisposes you to be not-right-handed? Handedness, then, could be a function of this genotype, and its interaction with the environment and random chance. </p>
<h2>Right/left asymmetry is actually common</h2>
<p>Other left-right asymmetries abound in human biology. Perhaps the most striking is the asymmetrical layout of our internal organs — heart, lungs and digestive track. </p>
<p>But it’s the clockwise or counterclockwise whorl of hair that has had a central role in understanding the genetics of handedness. Much like the rotation of hurricanes and cyclones, the hair on our scalps forms a central spiral with a direction of rotation. (I’m not making this up, find a pair of mirrors, or the person sitting next to you, and check me on this — or look at this picture.) </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/202903/original/file-20180122-182945-26lpk0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202903/original/file-20180122-182945-26lpk0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202903/original/file-20180122-182945-26lpk0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202903/original/file-20180122-182945-26lpk0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202903/original/file-20180122-182945-26lpk0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202903/original/file-20180122-182945-26lpk0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202903/original/file-20180122-182945-26lpk0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hair whorls can run clockwise (as seen here) or counterclockwise.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/25891376@N00/421254473">(Noj Han/flickr)</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The whorl, and its direction, was the focus of a <a href="http://www.genetics.org/content/165/1/269.long">seminal paper on the genetics of handedness</a>. The scientist, Amar Klar, hung out in local malls and surreptitiously recorded the whorl direction of shoppers’ hair. Most had clockwise whorls. He didn’t record the shopper’s dominant hand — but he didn’t have to. Remember, the bias in handedness is almost universal.</p>
<p>Because 90 per cent of the human population is right-handed, Klar concluded that right-handedness and a clockwise whorl were correlated. He then directly surveyed a smaller group of people who had a counterclockwise whorl and found that this group split 50/50 between right-handed and not-right-handed. </p>
<p>In this way, Klar showed that handedness and whorl direction are associated, but not in a “all righties are clockwise; all lefties are counterclockwise” way. </p>
<h2>A single gene for handedness?</h2>
<p>Klar proposed an elegant alternative model that still only requires a single gene to determine both whorl direction and handedness. </p>
<p>Many genes have different forms, called alleles. We each carry two copies of every gene in our genome, one from mom and the other from dad. In some cases, but not all, one of these alleles is “dominant.” (Remember <a href="https://www.nature.com/scitable/topicpage/gregor-mendel-and-the-principles-of-inheritance-593">Gregor Mendel</a> and his wrinkled and smooth peas?) </p>
<p>In Klar’s model of hair and hands, the handedness gene has two alleles; if you have one or two copies of the dominant allele, you have a clockwise whorl and you’re a righty. But when you have two copies of the other form, chance comes into play — and that’s when things get interesting. </p>
<p>Klar’s interpretation is that these individuals always have the rare counterclockwise hair whorl and that they’re not right-handed about half the time. In other words, in these individuals, handedness is a genetic flip of the coin. </p>
<p>This kind of combination of genetics, the environment and simple random chance underlies most human biology, from height or weight to drug resistance or cancer susceptibility. Understanding the genetics of human handedness can, then, help us to understand human genetics in general.</p>
<h2>Other species?</h2>
<p>What about asymmetry and handedness in other species? </p>
<p>Like many “complex” behaviours (think language or tool use), we used to think of handedness as a uniquely human trait. Once we actually started looking, however, we’ve found “handedness” in many other species, from snails to kangaroos, even to our ancient evolutionary <a href="https://www.sciencedirect.com/science/article/pii/S0047248416300719">ancestors</a>. </p>
<p>Snails don’t have a dominant hand (or any hands, really), but their shells twist either right (almost all the time) or left (very rarely).</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/202904/original/file-20180122-182959-x9n0hs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202904/original/file-20180122-182959-x9n0hs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=547&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202904/original/file-20180122-182959-x9n0hs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=547&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202904/original/file-20180122-182959-x9n0hs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=547&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202904/original/file-20180122-182959-x9n0hs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=688&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202904/original/file-20180122-182959-x9n0hs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=688&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202904/original/file-20180122-182959-x9n0hs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=688&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Two different species of sea snail. One normally twists right, the other twists left.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Neptunea_-_links%26rechts_gewonden.jpg">(Wikimedia)</a></span>
</figcaption>
</figure>
<p>Cephalopods, octopus, cuttlefish and squid are a group of molluscs (like snails) that do have arms and, it turns out, are “handed.” When I briefly studied cephalopod behaviour in the 1980s, we didn’t think that octopus or cuttlefish could distinguish left from right, but <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5149545/">more recent work shows that they can</a> and that <a href="http://www.sciencedirect.com/science/article/pii/S0166432806002439">they have a preferred arm or side</a>. </p>
<p>Scale-eating cichlids, a sort of creepy fish that feeds exclusively on the scales of other, less fortunate, fish, <a href="https://academic.oup.com/gbe/article/9/11/3122/4563458">preferentially attack from the left or from the right</a>. </p>
<p>Your cat reaches for food with <a href="http://www.springer.com/us/book/9781461381419">its dominant paw</a>, but your leg-lifting dog is <a href="http://www.sciencedirect.com/science/article/pii/S0168159115001203">ambidextrous in its peeing preference</a>. </p>
<h2>Let’s experiment</h2>
<p>A central challenge in exploring the genetics of handedness in humans is our (completely justified) unwillingness to experiment on humans. I won’t genetically engineer my daughter to see if I can make her left-handed, but I’d be willing to try it on a snail. </p>
<p>Because handedness occurs in other species, we can study them to determine its genetic mechanism. This comparative approach underlies all model organisms; it is why, for example, we study the metabolism of <a href="https://theconversation.com/how-to-kill-fruit-flies-according-to-a-scientist-81740">fruit flies</a> to understand the <a href="https://video.vice.com/en_us/video/inside-the-dark-matter-lab-buried-over-a-mile-underground-11/5834aeb8d9f88aa65cd9ac80">biology of deep underground mining</a> and the <a href="http://www.g3journal.org/content/4/11/2175">genetics of chromosome cross-talk and cancer</a>.</p>
<p>One important point to keep in mind, though, is that similar systems aren’t necessarily controlled by the same genes. Klar, for example, found that organ asymmetry is determined by a genetic pathway that is distinct from the one for hair whorl and handedness. Handedness in cats or snails is likely genetic, but the genetics may not be identical to that in humans.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/202899/original/file-20180122-182941-1vx2v8h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/202899/original/file-20180122-182941-1vx2v8h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=277&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202899/original/file-20180122-182941-1vx2v8h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=277&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202899/original/file-20180122-182941-1vx2v8h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=277&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202899/original/file-20180122-182941-1vx2v8h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=347&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202899/original/file-20180122-182941-1vx2v8h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=347&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202899/original/file-20180122-182941-1vx2v8h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=347&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">American lobsters are just as likely to be right-clawed as left-clawed.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Animal handedness differs from us in another way, too. The extreme bias present in humans, that 90:10 ratio, doesn’t exist. Cats, for example, are just as likely to be right-pawed or left-pawed. American lobsters have a larger “crusher” claw and a sharper “cutter” claw, but <a href="http://www.lobsters.org/ldoc/ldocpage.php?did=443">the big, dominant claw is equally likely to be on the right or left</a>. <a href="http://www.sciencedirect.com/science/article/pii/S0960982215007307?via%3Dihub">Kangaroos tend to be lefties</a>, and <a href="http://www.lobsters.org/ldoc/ldocpage.php?did=443">chimps tend to be righties</a>, but in both the bias isn’t as strong as it is in humans. </p>
<h2>Why the bias in humans?</h2>
<p>Handedness is biologically complex and involves substantial co-ordination between the brain and hand. The brain is itself asymmetrical, with the left and right hemispheres playing different roles in co-ordinating activities such as <a href="https://www.ncbi.nlm.nih.gov/pubmed/3214588">pattern recognition</a> or <a href="https://academic.oup.com/brain/article/123/12/2512/325690">language</a>. </p>
<p>Interestingly, there seem to be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3975119/">subtle differences in the brain architecture</a> of righties and lefties. Does the bias, then, reflect some kind of wiring in the brain? Some studies have tied left-handedness to changes in brain function and <a href="http://www.huffingtonpost.ca/entry/left-handed-personality-psychology_us_58331757e4b058ce7aac163a">behaviour</a>. </p>
<p>There are also some groups in which lefties are over-represented, including <a href="http://journals.sagepub.com/doi/pdf/10.2466/pms.1977.45.3f.1216">artists and architects</a>. These numbers suggest that there is a creative benefit to being wired this way. </p>
<p>(The more observant, or pedantic, may be asking how this point fits with my initial observation that about 10 per cent of art students were lefties. The answer is likely sample size. I stood around in front of a lot of students — but still only couple of hundred. This may simply have not been big enough sample for me to see the jump to 20 per cent from 10 per cent. Sampling limitations are the bane of biologists.)</p>
<p>Possible creative, or cognitive, differences bring us back to my initial fascination, and envy, of that sinister minority.</p>
<p>If you need someone to cut along the dotted line with the first pair of scissors that come to hand, perhaps then any righty will do. But if you need someone to think outside the box, you might want to enlist a lefty. </p>
<p><em>Thanks to Jack Bateman, Jeff Arnold, Kim Fahner, and Jean Boal for their invaluable suggestions and for pointing me to some of the literature and ideas that support this piece. Any limitations in interpreting that literature is mine alone.</em></p><img src="https://counter.theconversation.com/content/90288/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Thomas Merritt receives funding from the Natural Science and Engineering Research Council and the Canada Research Chairs program. </span></em></p>Handedness is the tendency to prefer using one hand over the other to perform certain tasks. But how did we get this way?Thomas Merritt, Professor, Chemistry and Biochemistry, Laurentian UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/881982017-12-10T23:05:02Z2017-12-10T23:05:02ZYou’ve got your DNA kit: Now what can you do with it?<figure><img src="https://images.theconversation.com/files/198431/original/file-20171210-27674-unj6wl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A scientist works with DNA samples in a New Orleans laboratory in 2011.</span> <span class="attribution"><span class="source"> (AP Photo/Gerald Herbert)</span></span></figcaption></figure><p>Differences among people, such as eye colour or hair colour, come from slight variations in our genetic code. As technology advances, it’s getting easier to unlock the secrets in our DNA to gain new insights into who we are and to apply that knowledge to dramatically change our lives and society.</p>
<p>This has led many to get personal reports on their own genetic code in exchange for payment and saliva samples. Excitement over these reports recently jumped after <a href="http://www.oprah.com/gift/oprahs-favorite-things-2017-full-list-dna-test-ancestry-personal-genetic-service?editors_pick_id=71355">Oprah Winfrey recommended the DNA test by 23andMe on her annual favourite things list</a>.</p>
<p>But the applications of making DNA information more accessible stretch far beyond satisfying our curiosity about who we are and what our genes might say about us. </p>
<p>The availability of genetic data can potentially be tapped to treat medical conditions, leading to personalized health care and wellness regimens, with larger implications for personal, cultural, social and economic change. For example, companies such as Newtopia provide customers with <a href="http://www.goodhousekeeping.com/institute/a23581/newtopia-a-diet-based-on-your-dna/">weight-loss plans that are tailored to one’s own DNA</a>.</p>
<p>As researchers trained in economics, we study the impact of how genetic and environmental factors influence the development of human capital measures such as education and health. As we learn more about our DNA, the possibilities that arise for policy and the economy as a whole are as numerous as our individual genomes are varied. </p>
<h2>DNA data can pose public risk</h2>
<p>Beyond private companies, the rapidly declining costs of both gene-sequencing and the technology to store genomic data has the potential to soon transform health-care delivery and policy. </p>
<p><a href="https://wol.iza.org/articles/what-is-the-role-for-molecular-genetic-data-in-public-policy/long">Our recent research considers the potential value from incorporating genetic data in the design of public policy</a> and <a href="https://link.springer.com/epdf/10.1186/s40173-017-0080-6?author_access_token=tokabk3A5sGAY9DDBwhlcW_BpE1tBhCbnbw3BuzI2RPxRCGr4ipav-alb6J3IvVA4EO0ta2k5g7yH1LrAwVB8rGq4ZAzBAu2B3WRSAmD5FG5bfMZsrSFzsV5pE6ZvgEdT4-nvwMYMHxmgD48yrHGTA==">social science research</a>, as well as the risks. </p>
<p>Decisions about genetic policies involve complex issues about ethics, costs, benefits and individual and societal interests. </p>
<p>Legislation is needed to prevent insurance companies and employers from using the results from genetic tests when making decisions. Canada was the last member of the G7 to introduce protections with the <a href="http://www.parl.ca/DocumentViewer/en/42-1/bill/S-201/royal-assent">Act to Prohibit and Prevent Genetic Discrimination</a> (formerly Bill S-201) this year — nine years after the United States passed similar legislation.</p>
<p>Since genetic factors may explain individual differences in socioeconomic outcomes, a growing number of social science data sets now involve biological-specimen collection activities that permit measuring genetic factors. Analyses of this data can extend and expand our knowledge on virtually every health condition — and on socioeconomic traits that have a genetic basis.</p>
<h2>Environment also plays a role</h2>
<p>However, genetic factors are only part of the story and other variables that are well-studied by social scientists —such as environment and lifestyle — also come into play. For example, an emerging body of evidence now indicates that genetic associations with <a href="http://www.pnas.org/content/112/2/354">obesity may vary due to different prevailing environmental factors</a> like occupation and even urban design.</p>
<p>These differences in environments, lifestyles and genetic factors have important implications in areas ranging from health behaviours such as obesity and cigarette smoking to skill development and other socio-economic outcomes. Therefore the idea of a one-size-fits-all policy for any health, education or socioeconomic outcome is flawed. </p>
<p>Adopting one-size-fits-all policies assume that the same process can produce a health or socioeconomic outcome for all individuals. However, if and how substantial genetic variations change the way these outcomes develop, opportunities emerge to create more effective treatments and policies.</p>
<p>Within the health-care realm, understanding the genetic basis of specific medical conditions is valuable since it offers the potential to improve treatment decisions.</p>
<p>With this new knowledge, we could replace current health and medical practices and develop new ones to target personalized policies and treatments more efficiently for different individuals.</p>
<h2>Heredity expands impact</h2>
<p>The intersection of genetics and public policy stretches beyond the health-care sector. <a href="http://psych.colorado.edu/%7Ecarey/hgss/hgssapplets/heritability/heritability.intro.html">Heritability</a> plays a role in nearly every socio-economic and education outcome. Heredity ensures policies that consider the role of genetics will have immediate and long-term implications.</p>
<p>The quality of evidence on the role of genetic factors on socioeconomic traits has increased sharply over the last decade.</p>
<p>With newer molecular DNA data available to empirical researchers, the flood of research findings linking specific genetic factors with individual health and socioeconomic outcomes will only continue to grow. </p>
<p>Yet it remains essential to ensure that these findings are interpreted correctly. Much of the evidence reflects only simple associations between individual genetic factors and socioeconomic outcomes — not causal relationships. And the impact of most genetic factors are often very small in magnitude.</p>
<h2>Small effects, big outcomes</h2>
<p>Nonetheless, there is often value from these findings. For example, <a href="http://brcatool.stanford.edu/">a calculator developed by the Stanford Cancer Institute</a> provides individuals with information on how their chances of survival change in response to different preventive measures taken at different ages.</p>
<p>The calculation is based on several specific differences in genetic markers, and helps educate individuals on the trade-offs they face when choosing among possible treatments.</p>
<p>More generally, the speed at which molecular genetic data can be effectively integrated within policy design is directly tied to improving our understanding how genetic markers operate. </p>
<p>For example, if genetic screening can reliably predict complex learning disorders, the advantages would be huge. Even if a disorder is a function of many genes — each with very small effects — researchers can calculate a single aggregate summary score.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/198433/original/file-20171210-27686-jmn12s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/198433/original/file-20171210-27686-jmn12s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198433/original/file-20171210-27686-jmn12s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198433/original/file-20171210-27686-jmn12s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198433/original/file-20171210-27686-jmn12s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198433/original/file-20171210-27686-jmn12s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198433/original/file-20171210-27686-jmn12s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Using genetic testing to determine your child has a learning disorder could help parents make the right decisions for their children.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>The summary score would measure an individual’s risk for a specific disorder or trait, which, in many situations, may take psychologists years to diagnose.</p>
<p>Armed with knowledge of whether their child is at an elevated risk for a learning disorder or other conditions, for example, parents will be able to make different investments in their child years before receiving a formal diagnosis. </p>
<h2>Change the conversation fast</h2>
<p>These investments may additionally affect how the underlying genes manifest themselves and therefore reduce the risk for future poor outcomes. As knowledge advances, the predictive accuracy of these summary scores will increase.</p>
<p>All of this reinforces the need for policies that consider not only the benefits, but the potential costs, of this newly available genetic data source. </p>
<p>Whether Canadians will fully realize the significant potential benefits from incorporating genetic data in health and social policy design will depend on how fast policies that ensure appropriate safeguards are developed.</p>
<p>If Canada hopes to capitalize on the great potential of DNA data to improve the lives of Canadians, policymakers and stakeholders must determine how to maximize the benefits while minimizing the harm.</p>
<p>Just as it should have regarding the genetic discrimination law, Canada must take quicker action in the future to ensure its citizens benefit from the explosion of DNA data.</p><img src="https://counter.theconversation.com/content/88198/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steven Lehrer receives funding from SSHRC. </span></em></p><p class="fine-print"><em><span>Weili Ding does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The rapid growth of genetic testing and data-gathering could revolutionize health and medicine if governments work to protect people against privacy and societal risks.Steven Lehrer, Associate Professor of Economics, Queen's University, OntarioWeili Ding, Associate professor, Queen's University, OntarioLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/824192017-08-22T01:59:38Z2017-08-22T01:59:38ZScared of CRISPR? 40 years on, IVF shows how fears of new medical technology can fade<figure><img src="https://images.theconversation.com/files/182872/original/file-20170822-8916-y977a5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">With all these 'test-tube babies' grown up, how have our reactions to the technology evolved?</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Associated-Press-International-News-United-King-/5d990e8aa9e4da11af9f0014c2589dfb/2/0">AP Photo/Alastair Grant</a></span></figcaption></figure><p>The first “test-tube baby” made headlines around the world in 1978, setting off intense debate on the ethics of researching human embryos and reproductive technologies. Every breakthrough since then has raised the same questions about “<a href="https://www.scientificamerican.com/article/regulate-designer-babies/">designer babies</a>” and “<a href="https://www.washingtonpost.com/opinions/if-were-going-to-play-god-with-gene-editing-weve-got-to-ask-some-moral-questions/2017/02/20/e4e0c396-f787-11e6-be05-1a3817ac21a5_story.html">playing God</a>” – but public response has grown more subdued rather than more engaged as assisted reproductive technologies have become <a href="https://doi.org/10.7916/D8FB5CQC">increasingly sophisticated and powerful</a>.</p>
<p>As the science has advanced, doctors are able to perform more complex procedures with <a href="https://doi.org/10.1111/ajo.12356">better-than-ever success rates</a>. This progress has made in vitro fertilization and associated assisted reproductive technologies relatively commonplace. <a href="http://www.sart.org/news-and-publications/news-and-research/press-releases-and-bulletins/SART_Data_Release_2015_Preliminary_and_2014_Final/">Over one million babies</a> have been born in the U.S. using IVF since 1985.</p>
<p>And Americans’ acceptance of these technologies has evolved alongside their increased usage, as we’ve gotten used to the idea of physicians manipulating embryos. </p>
<p>But the ethical challenges posed by these procedures remain – and in fact are increasing along with our capabilities. While still a long way from clinical use, the recent news that scientists in Oregon had <a href="https://doi.org/10.1038/nature23305">successfully edited genes in a human embryo</a> brings us one step closer to changing the DNA that we pass along to our descendants. As the state of the science continues to advance, ethical issues need to be addressed before the next big breakthrough.</p>
<h2>Birth of the test-tube baby era</h2>
<p>Louise Brown was born in the U.K. on July 25, 1978. Known as the first “test-tube baby,” <a href="http://www.bbc.com/news/health-33599353">she was a product of IVF</a>, a process where an egg is fertilized by sperm outside of the body before being implanted into the womb. IVF opened up the possibility for infertile parents to have their own biologically related children. But Brown’s family was also subjected to <a href="http://www.telegraph.co.uk/news/health/11760004/Louise-Brown-the-first-IVF-baby-reveals-family-was-bombarded-with-hate-mail.html">vicious hate mail</a>, and groups opposed to IVF warned it would be used for <a href="http://yalebooks.yale.edu/book/9780300137156/new-eugenics">eugenic experiments</a> leading to a dystopian future where all babies would be genetically engineered. </p>
<p>The reaction in the U.S. had another layer to it when compared to other developed countries. Here, research on embryos has <a href="https://doi.org/10.1038/sj.gt.3301744">historically been linked to the debate on abortion</a>. The 1973 Supreme Court decision to make abortion legal in Roe v. Wade fueled anti-abortion groups, <a href="http://www.lifenews.com/2011/09/06/pro-life-concerns-about-ivf-include-abortion-exploitation/">who also oppose research on human embryos</a>.</p>
<p>Embryonic research and procedures offer the hope of eliminating devastating diseases, but scientists also destroy embryos in the process. Under pressure from these groups over the ethical implications of embryo creation and destruction, <a href="https://doi.org/10.1038/sj.gt.3301744">Congress issued a moratorium in 1974</a> on federally funded clinical research on embryos and embryonic tissue, including on IVF, infertility and prenatal diagnosis. To this day, federal funds are still not available for this type of work.</p>
<p>In hindsight, the sharp media attention and negative response from anti-abortion groups to IVF didn’t accurately represent overall public opinion. The majority of Americans (60 percent) were in favor of IVF <a href="http://www.gallup.com/poll/8983/gallup-brain-birth-vitro-fertilization.aspx">when polled in August 1978</a>, and 53 percent of those polled said they would be willing to try IVF if they were unable to have a child.</p>
<p>So while the intense media coverage at the time helped inform the public of this new development, the insensitive labeling of Louise Brown as a “test-tube baby” and warnings about dystopian results didn’t stop Americans from forming positive opinions of IVF.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=409&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=409&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=409&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=514&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=514&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182873/original/file-20170822-5029-tvzs8c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=514&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Opinions evolved over the years as we got to know more ‘test-tube babies’ like Louise Brown.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Watchf-Associated-Press-Domestic-News-Illinois-/c13743ff67f24383a37c047f7684e157/1/0">AP Photo/FHJ</a></span>
</figcaption>
</figure>
<h2>Is embryonic research a moral issue?</h2>
<p>In the 40 years since IVF was introduced for use in humans, scientists have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3799275/">developed several new technologies</a> – from freezing eggs to genetically testing embryos before implantation – that have improved patient experience as well as the chances that IVF will result in the birth of a baby. The announcement of each of these breakthroughs has resulted in flurries of media attention to the ethical challenges raised by this type of research, but there has been no consensus – social, political or scientific – on how to proceed.</p>
<p>Americans’ general opinion of assisted reproductive technologies has remained positive. Despite opposition groups’ efforts, surveys show that Americans have separated out the issue of abortion from embryonic research. <a href="http://www.pewforum.org/2013/08/15/abortion-viewed-in-moral-terms/">A Pew Research Center poll from 2013</a> revealed that only 12 percent of Americans say they personally consider using IVF to be morally wrong. That’s a significant decrease from the <a href="http://www.gallup.com/poll/8983/Gallup-Brain-Birth-Vitro-Fertilization.aspx">28 percent of respondents in 1978</a> who replied that they opposed the procedure for being “not natural.” In addition, the 2013 poll showed that twice as many Americans (46 percent) said they <a href="http://www.pewforum.org/2013/08/15/abortion-viewed-in-moral-terms/">do not personally consider using IVF to be a moral issue</a> compared to the number of Americans (23 percent) who said they personally do not consider having an abortion to be a moral issue.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=383&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=383&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=383&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=482&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=482&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182874/original/file-20170822-28104-152rqaw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=482&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">We’re still a little hazy on the specifics of technologies that use human embryos.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Ballot-Stem-Cell-Research/9267ae5cd8e344b9ba3fd318bcd614ad/41/0">AP Photo/Paul Sancya</a></span>
</figcaption>
</figure>
<h2>Why we need to pay attention</h2>
<p>Although most Americans don’t think of embryonic research and procedures like IVF as a moral issue or morally wrong, the introduction of new technologies is outpacing Americans’ understanding of what they actually do.</p>
<p><a href="http://www.thenewatlantis.com/publications/public-opinion-and-the-embryo-debates">Polls from 2007-2008</a> showed that only 17 percent of respondents reported that they were “very familiar” with stem cell research, and that there was a “relative absence of knowledge about even the most prominent of the embryo-research issues.” When Americans are asked more specific questions that explain IVF, they show less support for certain procedures, like freezing and storing eggs or using embryos for scientific research.</p>
<p>In light of recent developments, surveys show that <a href="https://doi.org/10.1056/NEJMp1602010">nearly 69 percent of Americans</a> have not heard or read much or know nothing at all about gene editing. Additionally, support for gene editing depends on how the technology will be used. A majority of Americans generally accept gene editing if the purpose is to improve the health of a person, or if it will prevent a child from inheriting certain diseases. The scientists in Oregon <a href="https://doi.org/10.1038/nature23305">used a gene-editing technique</a> that allowed them to <a href="https://www.statnews.com/2017/07/26/human-embryos-edited/">correct a genetic defect in human embryos</a> that causes heart disease. This type of progress falls into the category that most Americans would support.</p>
<p>But the technique that’s used to make this correction, known as CRISPR-Cas9, can potentially be used for editing genes in other ways, not just to eliminate diseases. The success of the Oregon team opens the door to many possibilities in gene editing, including ones unrelated to health, such as changes to appearance or other physical characteristics.</p>
<p>Advancements in assisted reproductive technologies have happened rapidly over the last few decades, leading to <a href="https://www.cbsnews.com/news/report-5-million-babies-born-thanks-to-assisted-reproductive-technologies/">over five million births worldwide</a>. But as common as these procedures have become, scientists are not yet in agreement over how to integrate CRISPR and gene editing to the IVF toolkit. There are concerns about changing the genomes of human embryos destined to be babies, particularly since any modifications would be passed on to future generations. <a href="https://www.theguardian.com/science/2015/dec/03/gene-editing-summit-rules-out-ban-on-embryos-destined-to-become-people-dna-human">Scientific committees have noted</a> that decisions on whether and how to use gene editing should be revisited on a regular basis. The newest breakthrough with CRISPR is providing us with one of those opportunities.</p>
<p>We should focus our attention on answering the ethical questions that have long gone unanswered: What are the boundaries to this type of research? Who decides what is an ethical use of CRISPR? What responsibility do we have to people affected by genetic conditions? Who pays for these medical procedures? How will this research and potential clinical use be regulated? </p>
<p>The successful use of assisted reproductive technologies has skyrocketed in the last decade, making Americans complacent about some of the ethical concerns that these procedures raise. It’s important that we engage with these issues now, before gene editing becomes as familiar to us as IVF.</p><img src="https://counter.theconversation.com/content/82419/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Patricia Stapleton does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Americans have moved on from worrying about ‘test-tube babies’ – but there are still ethical challenges to resolve as reproductive technologies continue to advance.Patricia Stapleton, Assistant Professor of Political Science, Worcester Polytechnic InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/817322017-07-28T15:40:07Z2017-07-28T15:40:07ZEditing human embryos with CRISPR is moving ahead – now’s the time to work out the ethics<figure><img src="https://images.theconversation.com/files/180229/original/file-20170728-15340-1460v93.jpg?ixlib=rb-1.1.0&rect=35%2C73%2C1173%2C805&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There's still a way to go from editing single-cell embryos to a full-term 'designer baby.'</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/zeissmicro/27771482282">ZEISS Microscopy</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The announcement by researchers in Portland, Oregon that they’ve successfully modified the genetic material <a href="https://www.technologyreview.com/s/608350/first-human-embryos-edited-in-us/">of a human embryo</a> took some people by surprise.</p>
<p>With headlines referring to “<a href="https://www.businesslive.co.za/bd/world/americas/2017-07-27-us-university-edits-embryo-genes-in-experiment-hailed-as-groundbreaking/">groundbreaking</a>” research and “<a href="http://www.dailymail.co.uk/sciencetech/article-4734364/First-editing-human-embryos-carried-United-States.html">designer babies</a>,” you might wonder what the scientists actually accomplished. This was a big step forward, but hardly unexpected. As this kind of work proceeds, it continues to raise questions about ethical issues and how we should we react.</p>
<h2>What did researchers actually do?</h2>
<p>For a number of years now we have had the ability to alter genetic material in a cell, using a technique called CRISPR.</p>
<p>The DNA that makes up our genome comprises long sequences of base pairs, each base indicated by one of four letters. These letters form a genetic alphabet, and the “words” or “sentences” created from a particular order of letters are the genes that determine our characteristics.</p>
<p>Sometimes words can be “misspelled” or sentences slightly garbled, resulting in a disease or disorder. Genetic engineering is designed to correct those mistakes. CRISPR is a tool that enables scientists to target a specific area of a gene, working like the search-and-replace function in Microsoft Word, to remove a section and insert the “correct” sequence. </p>
<p>In the last decade, CRISPR has been the primary tool for those seeking to modify genes – human and otherwise. Among other things, it has been used in experiments to make <a href="https://doi.org/10.1038/nbt.3439">mosquitoes resistant to malaria</a>, genetically <a href="http://www.genengnews.com/gen-exclusives/crispr-applications-in-plants/77900846">modify plants to be resistant to disease</a>, explore the possibility of <a href="https://doi.org/10.1038/nature.2015.18448">engineered pets</a> and <a href="https://www.sciencenews.org/blog/science-ticker/crispr-used-cows-help-fight-tuberculosis">livestock</a>, and potentially treat some human diseases (including <a href="http://sites.tufts.edu/crispr/applications/hiv-treatment/">HIV</a>, <a href="https://doi.org/10.15252/emmm.201606325">hemophilia</a> and <a href="https://doi.org/10.1016/j.omtn.2016.12.012">leukemia</a>).</p>
<p>Up until recently, the focus in humans has been on changing the cells of a single individual, and not changing eggs, sperm and early embryos – what are called the “germline” cells that pass traits along to offspring. The theory is that focusing on non-germline cells would limit any unexpected long-term impact of genetic changes on descendants. At the same time, this limitation means that we would have to use the technique in every generation, which affects its potential therapeutic benefit.</p>
<p>Earlier this year, an international committee convened by the National Academy of Sciences <a href="https://doi.org/10.17226/24623">issued a report</a> that, while highlighting the concerns with human germline genetic engineering, laid out a series of <a href="http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=24623">safeguards and recommended oversight</a>. The report was widely regarded as opening the door to embryo-editing research.</p>
<p>That is exactly what happened in Oregon. Although this is the first study reported in the United States, similar research has been <a href="https://doi.org/10.1007/s13238-015-0153-5">conducted in China</a>. This new study, however, apparently avoided previous errors we’ve seen with CRISPR – such as changes in other, untargeted parts of the genome, or the desired change not occurring in all cells. Both of these problems had made scientists wary of using CRISPR to make changes in embryos that might eventually be used in a human pregnancy. Evidence of more successful (and thus safer) CRISPR use may lead to additional studies involving human embryos.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180203/original/file-20170728-5295-1tgc36j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">We have a ways to go before ordering up desired traits in a future baby. Researchers at Oregon Health and Science University say they worked with single-cell embryos, inserting CRISPR chemicals at the time of fertilization.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/lunarcaustic/3233482244">lunar caustic</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>What didn’t happen in Oregon?</h2>
<p>First, this study did not entail the creation of “designer babies,” despite some news headlines. The research involved only early stage embryos, outside the womb, none of which was allowed to develop beyond a few days.</p>
<p>In fact, there are a number of existing limits – both policy-based and scientific – that will create barriers to implanting an edited embryo to achieve the birth of a child. There is a <a href="https://www.nih.gov/about-nih/who-we-are/nih-director/statements/statement-nih-funding-research-using-gene-editing-technologies-human-embryos">federal ban on funding</a> gene editing research in embryos; in some states, there are also <a href="https://nyscf.org/scmapus">total bans on embryo research</a>, regardless of how funded. In addition, the implantation of an edited human embryos would be regulated under the <a href="https://humansubjects.nih.gov/pregnant-women-human-fetuses-neonates">federal human research regulations</a>, the <a href="https://www.fda.gov/biologicsbloodvaccines/cellulargenetherapyproducts/">Food, Drug and Cosmetic Act</a> and potentially the federal rules regarding <a href="https://wwwn.cdc.gov/CLIA/Regulatory/default.aspx">clinical laboratory testing</a>.</p>
<p>Beyond the regulatory barriers, we are a long way from having the scientific knowledge necessary to design our children. While the Oregon experiment focused on a single gene correction to inherited diseases, there are few human traits that are controlled by one gene. Anything that involves multiple genes or a gene/environment interaction will be less amenable to this type of engineering. Most characteristics we might be interested in designing – such as intelligence, personality, athletic or artistic or musical ability – are much more complex.</p>
<p>Second, while this is a significant step forward in the science regarding the use of the CRISPR technique, it is only one step. There is a long way to go between this and a cure for various disease and disorders. This is not to say that there aren’t concerns. But we have some time to consider the issues before the use of the technique becomes a mainstream medical practice.</p>
<h2>So what should we be concerned about?</h2>
<p>Taking into account the cautions above, we do need to decide when and how we should use this technique.</p>
<p>Should there be limits on the types of things you can edit in an embryo? If so, what should they entail? These questions also involve deciding who gets to set the limits and control access to the technology.</p>
<p>We may also be concerned about who gets to control the subsequent research using this technology. Should there be state or federal oversight? Keep in mind that we cannot control what happens in other countries. Even in this country it can be difficult to craft guidelines that restrict only the research someone finds objectionable, while allowing other important research to continue. Additionally, the use of assisted reproductive technologies (IVF, for example) is <a href="http://www.rockinst.org/pdf/health_care/2009-07-States_Regulation_ART.pdf">largely unregulated in the U.S.</a>, and the decision to put in place restrictions will certainly raise objections from both potential parents and IVF providers.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180211/original/file-20170728-18243-1g5vqx3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Who should be able to use this technology? And who should decide?</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/j2dread/5595599661">Johnathan D. Anderson</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Moreover, there are important questions about cost and access. Right now most assisted reproductive technologies are available only to higher-income individuals. A handful of <a href="http://www.ncsl.org/research/health/insurance-coverage-for-infertility-laws.aspx">states mandate infertility treatment coverage</a>, but it is very limited. How should we regulate access to embryo editing for serious diseases? We are in the midst of a <a href="https://theconversation.com/us/topics/us-health-care-reform-40185">widespread debate</a> about health care, access and cost. If it becomes established and safe, should this technique be part of a basic package of health care services when used to help create a child who does not suffer from a specific genetic problem? What about editing for nonhealth issues or less serious problems – are there fairness concerns if only people with sufficient wealth can access?</p>
<p>So far the promise of genetic engineering for disease eradication has not lived up to its hype. Nor have many other milestones, like the 1996 <a href="https://theconversation.com/20-years-after-dolly-everything-you-always-wanted-to-know-about-the-cloned-sheep-and-what-came-next-72655">cloning of Dolly the sheep</a>, resulted in the feared apocalypse. The announcement of the Oregon study is only the next step in a long line of research. Nonetheless, it is sure to bring many of the issues about embryos, stem cell research, genetic engineering and reproductive technologies back into the spotlight. Now is the time to figure out how we want to see this gene-editing path unfold.</p><img src="https://counter.theconversation.com/content/81732/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jessica Berg does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The news may have come as a surprise, but it probably shouldn’t have. A bioethics expert walks through how big a deal this announcement is – and what we should be considering now.Jessica Berg, Law Dean; Professor of Law; and Professor of Bioethics & Public Health, Case Western Reserve UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/656062017-04-07T01:35:28Z2017-04-07T01:35:28ZDNA dating: How molecular clocks are refining human evolution’s timeline<figure><img src="https://images.theconversation.com/files/164196/original/image-20170405-14615-pgkdmv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Our cells have a built-in genetic clock, tracking time... but how accurately?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hand-holding-retro-stopwatch-black-white-256422460">Stopwatch image via www.shutterstock.com.</a></span></figcaption></figure><p>DNA holds the story of our ancestry – how we’re related to the familiar faces at family reunions as well as more ancient affairs: how we’re related to our closest nonhuman relatives, chimpanzees; how <em>Homo sapiens</em> mated with Neanderthals; and how people migrated out of Africa, adapting to new environments and lifestyles along the way. And our DNA also holds clues about the timing of these key events in human evolution.</p>
<p>When scientists say that <a href="http://doi.org/10.1038/nature18964">modern humans emerged</a> in Africa about 200,000 years ago and began their global spread about 60,000 years ago, how do they come up with those dates? Traditionally researchers built timelines of human prehistory based on fossils and artifacts, which can be directly dated with methods such as <a href="https://theconversation.com/explainer-what-is-radiocarbon-dating-and-how-does-it-work-9690">radiocarbon dating</a> and Potassium-argon dating. However, these methods require ancient remains to have certain elements or preservation conditions, and that is not always the case. Moreover, relevant fossils or artifacts have not been discovered for all milestones in human evolution.</p>
<p>Analyzing DNA from present-day and ancient genomes provides a complementary approach for dating evolutionary events. Because certain genetic changes occur at a steady rate per generation, they provide an estimate of the time elapsed. These changes accrue like the ticks on a stopwatch, providing a “molecular clock.” By comparing DNA sequences, geneticists can not only reconstruct relationships between different populations or species but also infer evolutionary history over deep timescales.</p>
<p>Molecular clocks are becoming more sophisticated, thanks to improved DNA sequencing, analytical tools and a better understanding of the biological processes behind genetic changes. By applying these methods to the ever-growing database of DNA from diverse populations (both present-day and ancient), geneticists are helping to build a more refined timeline of human evolution.</p>
<h2>How DNA accumulates changes</h2>
<p>Molecular clocks are based on two key biological processes that are the source of all heritable variation: mutation and recombination. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164195/original/image-20170405-14612-1cas5ot.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mutations are changes to the DNA code, such as when one nucleotide base (A, T, G or C) is incorrectly subbed for another.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/vector-illustration-dna-structure-303407264">DNA image via www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>Mutations are changes to the letters of DNA’s genetic code – for instance, a nucleotide Guanine (G) becomes a Thymine (T). These changes will be inherited by future generations if they occur in eggs, sperm or their cellular precursors (the germline). Most result from mistakes when DNA copies itself during cell division, although other <a href="https://doi.org/10.1146/annurev-genom-031714-125740">types of mutations</a> occur spontaneously or from exposure to hazards like radiation and chemicals.</p>
<p>In a single human genome, there are about <a href="https://doi.org/10.1038/nature11396">70 nucleotide changes per generation</a> – minuscule in a genome made up of six billion letters. But in aggregate, over many generations, these changes lead to substantial evolutionary variation.</p>
<p>Scientists can use mutations to estimate the timing of branches in our evolutionary tree. First they compare the DNA sequences of two individuals or species, counting the neutral differences that don’t alter one’s chances of survival and reproduction. Then, knowing the rate of these changes, they can calculate the time needed to accumulate that many differences. This tells them how long it’s been since the individuals shared ancestors.</p>
<p>Comparison of DNA between you and your sibling would show relatively few mutational differences because you share ancestors – mom and dad – just one generation ago. However, there are millions of differences between <a href="https://doi.org/10.1038/nature04072">humans and chimpanzees</a>; our last common ancestor lived over six million years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=237&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=237&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=237&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=298&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=298&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164351/original/image-20170406-16660-iq0fym.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=298&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bits of the chromosomes from your mom and your dad recombine as your DNA prepares to be passed on.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/phases-meiosis-1-172528943">Chromosomes image via www.shutterstock.com.</a></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.1038/nrg1947">Recombination</a>, also known as crossing-over, is the other main way DNA accumulates changes over time. It leads to shuffling of the two copies of the genome (one from each parent), which are bundled into chromosomes. During recombination, the corresponding (homologous) chromosomes line up and exchange segments, so the genome you pass on to your children is a mosaic of your parents’ DNA.</p>
<p>In humans, <a href="https://doi.org/10.1038/nature09525">about 36 recombination events</a> occur per generation, one or two per chromosome. As this happens every generation, segments inherited from a particular individual get broken into smaller and smaller chunks. Based on the size of these chunks and frequency of crossovers, geneticists can estimate how long ago that individual was your ancestor.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=699&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=699&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=699&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=879&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=879&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164352/original/image-20170406-16665-1ykda9r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=879&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Gene flow between divergent populations leads to chromosomes with mosaic ancestry. As recombination occurs in each generation, the bits of Neanderthal ancestry in modern human genomes becomes smaller and smaller over time.</span>
<span class="attribution"><span class="source">Bridget Alex</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Building timelines based on changes</h2>
<p>Genetic changes from mutation and recombination provide two distinct clocks, each suited for dating different evolutionary events and timescales.</p>
<p>Because mutations accumulate so slowly, this clock works better for very ancient events, like evolutionary splits between species. The recombination clock, on the other hand, ticks at a rate appropriate for dates within the last 100,000 years. These “recent” events (in evolutionary time) include gene flow between distinct human populations, the rise of beneficial adaptations or the emergence of genetic diseases.</p>
<p>The case of Neanderthals illustrates how the mutation and recombination clocks can be used together to help us untangle complicated ancestral relationships. Geneticists estimate that there are 1.5-2 million mutational differences between Neanderthals and modern humans. Applying the mutation clock to this count suggests the groups initially split between <a href="https://doi.org/10.1038/nature12886">750,000 and 550,000 years ago</a>.</p>
<p>At that time, a population – the common ancestors of both human groups – separated geographically and genetically. Some individuals of the group migrated to Eurasia and over time evolved into Neanderthals. Those who stayed in Africa became anatomically modern humans. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164194/original/image-20170405-14620-3re7gz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An evolutionary tree displays the divergence and interbreeding dates that researchers estimated with molecular clock methods for these groups.</span>
<span class="attribution"><span class="source">Bridget Alex</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>However, their interactions were not over: Modern humans eventually spread to Eurasia and mated with Neanderthals. Applying the recombination clock to Neanderthal DNA retained in present-day humans, researchers estimate that the <a href="http://doi.org/10.1073/pnas.1514696113">groups interbred between 54,000 and 40,000 years ago</a>. When scientists analyzed a <em>Homo sapiens</em> fossil, known as Oase 1, who lived around 40,000 years ago, they found large regions of Neanderthal ancestry embedded in the Oase genome, suggesting that Oase had a <a href="http://doi.org/10.1038/nature14558">Neanderthal ancestor just four to six generations ago</a>. In other words, Oase’s great-great-grandparent was a Neanderthal. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=235&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=235&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=235&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=295&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=295&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164193/original/image-20170405-14626-lvvz51.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=295&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Comparing chromosome 6 from the 40,000-year-old Oase fossil to a present-day human. The blue bands represent segments of Neanderthal DNA from past interbreeding. Oase’s segments are longer because he had a Neanderthal ancestor just 4–6 generations before he lived, based on estimates using the recombination clock.</span>
<span class="attribution"><span class="source">Bridget Alex</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>The challenges of unsteady clocks</h2>
<p>Molecular clocks are a mainstay of evolutionary calculations, not just for humans but for all forms of living organisms. But there are some complicating factors.</p>
<p>The main challenge arises from the fact that mutation and recombination rates have not remained constant over human evolution. The rates themselves are evolving, so they vary over time and may differ between species and even across human populations, albeit fairly slowly. It’s like trying to measure time with a clock that ticks at different speeds under different conditions.</p>
<p>One issue relates to a gene called <em>Prdm9</em>, which determines the location of those DNA crossover events. Variation in this gene in humans, chimpanzees and mice has been shown <a href="https://doi.org/10.1126/science.1183439">to alter recombination hotspots</a> – short regions of high recombination rates. Due to the evolution of <em>Prdm9</em> and hotspots, the fine-scale recombination rates <a href="https://doi.org/10.1126/science.1216872">differ between humans and chimps</a>, and <a href="https://doi.org/10.1038/nature10336">possibly also between Africans and Europeans</a>. This implies that over different timescales and across populations, the recombination clock ticks at <a href="http://www.nature.com/nrg/journal/v8/n1/execsumm/nrg1947.html">slightly different rates</a> as hotspots evolve.</p>
<p>Another issue is that mutation rates vary by sex and age. As fathers get older, they transmit <a href="https://doi.org/10.1038/ng.3597">a couple extra mutations to their offspring per year</a>. The sperm of older fathers has undergone more rounds of cell division, so more opportunities for mutations. Mothers, on the other hand, <a href="https://doi.org/10.1038/ng.3597">transmit fewer mutations</a> (about 0.25 per year) as a female’s eggs are mostly formed all at the same time, before her own birth. Mutation rates also <a href="https://doi.org/10.1073/pnas.1600374113">depend on factors like</a> onset of puberty, age at reproduction and rate of sperm production. These life history traits vary across living primates and probably also differed between extinct species of human ancestors.</p>
<p>Consequently, over the course of human evolution, the <a href="https://doi.org/10.1038/nrg3295">average mutation rate seems to have slowed</a> significantly. The average rate over millions of years since the split of humans and chimpanzees has been estimated as <a href="https://doi.org/10.1038/nature04072">about 1x10⁻⁹ mutations per site per year</a> – or roughly six altered DNA letters per year. This rate is determined by dividing the number of nucleotide differences between humans and other apes by the date of their evolutionary splits, as inferred from fossils. It’s like calculating your driving speed by dividing distance traveled by time passed. But when geneticists directly measure nucleotide differences between living parents and children (using human pedigrees), the mutation rate is half the other estimate: <a href="https://doi.org/10.1038/nature11396">about 0.5x10⁻⁹ per site per year</a>, or only about three mutations per year. </p>
<p>For the divergence between Neanderthals and modern humans, the slower rate provides an estimate between 765,000-550,000 years ago. The faster rate, however, would suggest half that age, or 380,000-275,000 years ago: a big difference.</p>
<p>To resolve the question of which rates to use when and on whom, researchers have been developing new molecular clock methods, which address the challenges of evolving mutation and recombination rates.</p>
<h2>New approaches for better dating</h2>
<p>One approach is to focus on mutations that arise at a steady rate regardless of sex, age and species. This may be the case for a special type of mutation that geneticists call <a href="http://www.nature.com/nature/journal/v287/n5782/abs/287560a0.html">CpG transitions</a> by which the C nucelotides spontaneously become T’s. Because CpG transitions mostly do not result from DNA copying errors during cell division, their rates should be mainly independent of life history variables – and presumably more uniform over time. </p>
<p>Focusing on CpG transitions, geneticists recently estimated the split between humans and chimps to have occurred <a href="https://doi.org/10.1073/pnas.1600374113">between 9.3 and 6.5 million years ago</a>, which agrees with the age expected from fossils. While in comparisons across species, these mutations seem to happen more like clockwork than other types, they are still not completely steady.</p>
<p>Another approach is to develop models that adjust molecular clock rates based on sex and other life history traits. Using this method, researchers <a href="https://doi.org/10.1073/pnas.1515798113">calculated a chimp-human divergence</a> consistent with the CpG estimate and fossil dates. The drawback here is that, when it comes to ancestral species, we can’t be sure of life history traits, like age at puberty or generation length, leading to some uncertainty in the estimates.</p>
<p>The most direct solution comes from analyses of ancient DNA recovered from fossils. Because the fossil specimens are independently dated by geologic methods, geneticists can use them to calibrate the molecular clocks for a given time period or population.</p>
<p>This strategy recently resolved the debate over the timing of our divergence with Neanderthals. In 2016, geneticists extracted ancient DNA from <a href="https://doi.org/10.1038/nature17405">430,000-year-old fossils that were Neanderthal ancestors</a>, after their lineage split from <em>Homo sapiens</em>. Knowing where these fossils belong in the evolutionary tree, geneticists could confirm that for this period of human evolution, the slower molecular clock rate of 0.5x10⁻⁹ provides accurate dates. That puts the Neanderthal-modern human split between 765,000 to 550,000 years ago.</p>
<p>As geneticists sort out the intricacies of molecular clocks and sequence more genomes, we’re poised to learn more than ever about human evolution, directly from our DNA.</p><img src="https://counter.theconversation.com/content/65606/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bridget Alex has received research funding from the National Science Foundation (NSF).</span></em></p><p class="fine-print"><em><span>Priya Moorjani is supported by the NIH Ruth L. Kirschstein National Research Service Postdoctoral fellowship (grant number F32 GM115006-02).</span></em></p>How do scientists figure out when evolutionary events – like species splitting away from a common ancestor – happened? It turns out our DNA is a kind of molecular clock, keeping time via genetic changes.Bridget Alex, Postdoctoral College Fellow, Department of Human Evolutionary Biology, Harvard UniversityPriya Moorjani, Postdoctoral Research Fellow in Biological Sciences, Columbia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/625862016-08-12T10:12:51Z2016-08-12T10:12:51ZCan genetics explain the success of East African distance runners?<p>More than 10,000 athletes from 206 different nations will compete for glory in this year’s Olympic Games in Rio. But when it comes to distance running it’s likely that, <a href="http://www.runnersworld.com/rt-web-exclusive/the-ethiopiakenya-running-phenomenon">as in previous years</a>, the finals will be dominated by athletes from East African countries or those of East African heritage.</p>
<p>Why do athletes from this one region of the world tend to have such extraordinary success in one sport? It’s <a href="http://www.theatlantic.com/international/archive/2012/04/why-kenyans-make-such-great-runners-a-story-of-genes-and-cultures/256015/">often suggested</a> that it must be down to genetic factors. This would seem a logical assumption, based on the number of Olympic medals won by athletes from a relatively localised geographical area with relatively limited resources to spend on training.</p>
<p>As a result, it’s not surprising that <a href="http://bjsm.bmj.com/content/34/5/391.full">a number</a> of <a href="http://link.springer.com/article/10.2165/00007256-200737040-00039">scientific studies</a>
over the past 15 years have attempted to answer <a href="https://www.researchgate.net/profile/Yannis_Pitsiladis/publication/225064362_Kenyan_and_Ethiopian_Distance_Runners_What_Makes_Them_So_Good/links/54abb5f90cf2bce6aa1d9b69.pdf">this question</a>. There is some evidence that the typical body type of East African distance runners – with long, slender legs – may contribute to an increased efficiency in these athletes, particularly at race pace. Yet the overall findings of these research studies have not identified genetic traits that could conclusively explain the success of East African distance runners. </p>
<p>As elite sports performance is a complicated phenomenon, it is unlikely that athletic success will be the result of a single genetic factor. But it is possible that the success of these athletes could be down to a combination of interacting genes, which the <a href="http://vuir.vu.edu.au/23821/1/Pitsiladis%20et%20al%20BJSM%20final%20VUIR%20.pdf">latest genetic research</a> is trying to discover.</p>
<p>If genetic research alone cannot explain the dominance of East African distance runners, then what other factors might be behind their success? One factor often suggested is the extensive walking and running these athletes undertake from an <a href="http://europepmc.org/abstract/med/14523311">early age</a> – a total distance run to and from school is often cited at between <a href="http://etd-library.ku.ac.ke/bitstream/handle/123456789/5551/Demographic%20characteristics%20of%20elite%20Kenyan.pdf?sequence=4&isAllowed=y">5km and 20km</a>. However, this early introduction to endurance training does not appear to result in a higher maximal aerobic capacity (a key determinant of endurance performance) than that seen in elite <a href="https://www.researchgate.net/profile/Jan_Svedenhag/publication/15645883_Aerobic_exercise_capacity_at_sea_level_and_at_altitude_in_Kenyan_boys_junior_and_senior_runners_compared_with_Scandinavian_runners/links/552bed140cf2e089a3aac353.pdf">European distance runners</a>.</p>
<h2>Such great heights</h2>
<p>What about altitude? Many of the elite Kenyan and Ethiopian distance runners were born and raised at altitudes of around 2,000-2,500 metres. This may lead to superior levels of haemoglobin (a protein in red blood cells that carries oxygen throughout the body) and haematocrit (the volume of red blood cells in the blood). In turn, this leads to an increased ability to <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3824146/">transport oxygen</a> to the working muscles.</p>
<p>While just living at such altitudes may not alone explain the success, it appears that East African athletes also have the ability to train at high-intensity while at altitude. This is something that athletes without continual altitude exposure would find difficult to replicate. Iten and Addis Ababa – key training sites for Kenyan and Ethiopian distance runners respectively – both sit at around 2,400 metres above sea level. So it seems logical to assume that prolonged altitude exposure and the ability to train at a high-intensity while at altitude, may contribute in part to the success of East African distance runners.</p>
<p>A final reason often suggested for the East African dominance of distance running is the motivation to achieve economic success. In relatively poor countries, success in lucrative distance running events can considerably advance an athlete’s position in society.</p>
<p>We still can’t say conclusively what is behind the phenomenal success of the East African distance runners. But research suggests it is unlikely that there is a single genetic factor that can explain their success. But an optimal body type leading to excellent biomechanical efficiency may well play a part alongside the runners’ prolonged exposure to altitude and psychological motivation to succeed.</p><img src="https://counter.theconversation.com/content/62586/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andy Galbraith does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Unravelling the common assumption that runners from Kenya, Ethiopia and Somalia have a natural advantage.Andy Galbraith, Senior Lecturer in Exercise Physiology, University of East LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/598772016-05-25T04:21:37Z2016-05-25T04:21:37ZDNA Nation raises tough questions for Indigenous Australians<figure><img src="https://images.theconversation.com/files/123859/original/image-20160525-25213-rlqt7n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">DNA Nation raises questions of genetics, identity and race. </span> <span class="attribution"><span class="source">DNA Nation/SBS</span></span></figcaption></figure><p>The first episode of the long awaited SBS series <a href="http://www.sbs.com.au/topics/article/dna-nation-about-show">DNA Nation</a> screened on Sunday night. In between ads enticing the viewer to part with cash for the chance to be told they descend from a Viking or a Polynesian princess (free shipping if you order now!), we watched Ian Thorpe, Julia Zemiro and Ernie Dingo have their DNA sampled by a geneticist in a white coat and embark on an epic journey across the globe in the steps of their distant ancestors.</p>
<p>The premise is fantastic, and judging by the first episode, production company Blackfella Films has struck the right balance between sweeping landscapes, laboratory shots, Colin Friels’ authoritative narration of the science and Julia Zemiro’s facial expressions. </p>
<p>Tanzania is the backdrop of much of the episode, with the three stars mingling with the Hadza people who, we are told, are the direct descendants of the first Homo sapiens to evolve.</p>
<p>As the first episode closed we watched our intrepid travellers walk out of Africa, just like their ancestors some 50 000-100 000 years ago. From there, we are told, the three will part ways, each on their individual genetic journey. The suspense will entice many viewers back to see episode two, but others will be left with unanswered and uneasy questions.</p>
<h2>How African is Ernie?</h2>
<p>First things first. The focus on the Hadza as living-ancient-people that can reveal our inner nature was low-hanging fruit for critics of popular science, or for that matter, anyone with an Arts degree. </p>
<p>The whole point of flying three famous Australians to Tanzania is that we are all descended from Africans, not just the Hadza. Over the last 200,000 years, the humans that became the Hadza have changed and evolved, just as much as people who now identify as Slovenian, Japanese or Indigenous Australian. </p>
<p>I’m sure the Tanzanian tourism board and the Hadza appreciate the attention, but it is not good anthropology or good science.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123860/original/image-20160525-25213-1yejbb6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ernie Dingo with a Tanzanian boy.</span>
<span class="attribution"><span class="source">DNA Nation/SBS</span></span>
</figcaption>
</figure>
<p>We glimpsed the even bigger questions that DNA Nation glosses over when our man-in-a-white-coat skyped into Africa to reveal how much African DNA each of our three protagonists carried in their cells.</p>
<p>Ernie, Julia and Ian are all descendants of the humans that left Africa between 50 000 and 100 000 years ago to populate the rest of the world. So, unsurprisingly, each of them is the same amount of African – not very much.</p>
<p>Julia was visibly shocked that Ernie was not more African than she or Ian, since he has brown skin and effortlessly bonded with Hadza children, telling them the names of body parts in his Aboriginal language.</p>
<p>It is great to see Julia, and hopefully many viewers, replace their assumptions that “all brown people must be genetically similar” with a better understanding of science. </p>
<p>In fact, because all humans with recent ancestry outside Africa descend from a relatively small number of pioneers who left the continent, non-Africans have much less genetic diversity than Africans. </p>
<p>Julia and Ernie are likely to share more genetic code than two Africans would. But beyond correcting misconceptions, a-ha moments like these raise tougher questions about potential conflicts between western and Indigenous approaches to knowledge. </p>
<h2>Genetics and Indigenous identity</h2>
<p>Viewers had to switch channels to Stan Grant’s NITV talk show <a href="http://www.sbs.com.au/nitv/the-point-with-stan-grant/article/2016/02/25/how-watch-point-stan-grant">The Point</a> directly after DNA Nation for an airing of the tricky issues.</p>
<p>For instance, does the idea that everyone comes from Africa undermine the land rights of Indigenous Australians? The panel didn’t provide a clear answer, but we can: it doesn’t.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123891/original/image-20160525-25205-155ekfr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Stan Grant.</span>
<span class="attribution"><span class="source">DNA Nation/SBS</span></span>
</figcaption>
</figure>
<p>There is no sign that evolutionary science is eroding Indigenous rights in this country. In fact, genetic research into human origins is pushing the date of Indigenous occupation of Australia back <a href="http://www.australasianscience.com.au/article/issue-november-2011/aboriginal-genome-reveals-new-insights-early-humans.html">further and further</a>. </p>
<p>Could genetic ancestry testing ever be used by Aboriginal organisations, governments or courts to prove or disprove Aboriginality? </p>
<p>Indigenous ancestry is part of Indigenous identity, but other aspects – far beyond the reach of genetics – are just as crucial to Indigenous people, including cultural knowledge, community acceptance and connection to country. </p>
<p>The role of genetics in identity will now be a hot topic of debate, with a diversity of views among Indigenous people. Palawa elder Rodney Dillon, for example, argues that genetics could potentially resolve long running and damaging <a href="http://www.tasmaniantimes.com.au/index.php/article/brawl-over-wannabe-and-tick-a-box-aborigines">disputes about Aboriginality</a> within his own Tasmanian community.</p>
<p>In working through the issue, we should keep in mind that Australia has so far avoided the divisive politics of inclusion and exclusion that mar so many Indigenous groups in the United States (and more recently, in Canada), and we shouldn’t let anything change that. </p>
<p>Forget the can – genetics is a barrelful of worms. Indigenous people have known this for a long time, at least since the 1990s. </p>
<p>It was then that the Human Genome Diversity Project, widely known as the “Vampire Project”, sought to sample genetic diversity from Indigenous people around the world. It was a public relations disaster, with little or no consultation with Indigenous groups before it started. </p>
<p>The <a href="https://www.greenleft.org.au/node/7328">Central Australian Aboriginal Congress</a> called the project “legalised theft” of Indigenous genetic material. The reputation of genetic research among Indigenous groups went from bad to worse for the coming generation.</p>
<h2>Genomics is everywhere</h2>
<p>Fast forward two decades, and genomics seems to be everywhere. The massive acceleration in sequencing technology means that your genome will soon be an indispensable part of diagnosing and treating a wide range of diseases (and is <a href="https://www.genome.gov/27527652/genomic-medicine-and-health-care/">already used for some conditions</a>).</p>
<p>We are moving to an era of personalised medicine which may have real health benefits for Indigenous peoples. Getting “your DNA done” through a direct-to-consumer genetic testing company is increasingly common, and Indigenous Australians are among those paying up to learn about their genetic ancestry and possible health risks. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123874/original/image-20160525-25231-104dj9g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Julia Zemiro and Ian Thorpe on DNA Nation.</span>
<span class="attribution"><span class="source">DNA Nation/SBS</span></span>
</figcaption>
</figure>
<p>Aside from the political and ethical problems we have touched on here, there are also technical concerns with the genetic testing industry for Indigenous Australians.</p>
<p>For Indigenous viewers of DNA Nation who are inspired to trace their own genetic ancestry, the single company that offers Australian Aboriginal testing is the US based DNA Tribes.</p>
<p>Rather than the conventional method of maternal (mitochondrial DNA) and paternal (Y chromosome) testing used on DNA Nation, they use sections of DNA called single tandem repeats (STRs) that vary in the number of copies each person has. </p>
<p>DNA Tribes compare customers’ 23 pairs of chromosomes with databases from around the world, including Australia. The problem is that these are forensic databases appropriate for forensic casework and paternity testing, but not genetic genealogy.</p>
<p>We don’t know what “reference samples” DNA Tribes are using for Indigenous Australians or whether informed consent was given for the use of this data for commercial purposes. </p>
<p>While it is clear that there is not, and never will be, a genetic test for Aboriginality, advances in genomics will have flow on effects for identity and culture that need wide discussion.</p>
<h2>Flow on effects for identity</h2>
<p>Indigenous Australians should be able to access the potential benefits of ancestry testing, such as it helping with <a href="http://www.sbs.com.au/nitv/article/2016/05/10/thousands-dna-samples-may-reconnect-families-torn-apart-assimilation-policies">family reconnection</a>, and shouldn’t miss out on the potential health benefits of genomics. That’s why we need to face the tough questions raised by genetics for Indigenous people, however thorny they may be. </p>
<p>The only certainty here is the importance of full Indigenous engagement in every aspect of genomic science, from the start to the finish. </p>
<p>That’s the approach we take at the <a href="http://ncig.anu.edu.au/">National Centre for Indigenous Genomics</a>. The <a href="http://www.sbs.com.au/nitv/article/2016/05/17/will-indigenous-australia-lead-way-ethical-genetic-research">first Indigenous-governed genome facility in the world</a>, NCIG began when the Australian National University developed a management strategy for 7,000 blood samples collected from Indigenous communities, mostly in the 1960s and 70s. </p>
<p>At our centre, we will be listening carefully to the difficult conversations that DNA Nation will stimulate.</p><img src="https://counter.theconversation.com/content/59877/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emma Kowal is Deputy Director of the National Centre for Indigenous Genomics. She receives funding from the Australian Research Council, the National Health and Medical Research Council and the Lowitja Institute. </span></em></p><p class="fine-print"><em><span>Misty Jenkins is affiliated with The National Centre for Indigenous Genomics.</span></em></p>The SBS documentary DNA Nation tracks three people on their ‘individual genetic journey’. But for Indigenous Australians in particular, genetic testing is a can of worms - politically, ethically and technically.Emma Kowal, Professor of Anthropology, Deakin UniversityMisty Jenkins, Laboratory Head, Immunology, Walter and Eliza Hall InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/596502016-05-25T01:01:22Z2016-05-25T01:01:22ZWhat does it mean for researchers, journalists and the public when secrecy surrounds science?<figure><img src="https://images.theconversation.com/files/123803/original/image-20160524-25213-q3h9yn.jpg?ixlib=rb-1.1.0&rect=8%2C369%2C2968%2C2090&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People get suspicious when ethically fraught science is discussed behind closed doors.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic.mhtml?id=133184528&src=id">DNA image via www.shutterstock.com.</a></span></figcaption></figure><p>Did you hear about the secret meeting earlier this month at Harvard Medical School? The one where scientists schemed to create a parentless human being from scratch? Maybe you read one of the skeptical <a href="http://www.nytimes.com/2016/05/14/science/synthetic-human-genome.html">news</a> <a href="http://www.mercurynews.com/science/ci_29890402/critics-attack-harvards-secret-meeting-human-genome-synthesis">articles</a>, or the stories illustrated with images from the dystopian sci-fi classic “<a href="http://gizmodo.com/experts-held-a-secret-meeting-to-consider-building-a-hu-1776538323">Blade Runner</a>” or of a <a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2016/05/13/secret-harvard-meeting-on-synthetic-human-genomes-incites-ethics-debate/">robot Frankenstein</a>. One blogger compared the meeting to a gathering of “<a href="http://www.valuewalk.com/2016/05/secret-dna-meeting-held-at-harvard-screams-bond-villains/">Bond villains</a>.”</p>
<p>The press coverage was suspicious and critical. Why would a bunch of scientists need to exclude the media and the public from a meeting about something as ethically fraught as synthesizing a human genome?</p>
<p>Three weeks later, the exact details of what happened are still being contested. I’m a researcher in synthetic biology, and I learned of the project from reading the newspaper. I reached out to the meeting’s organizers, who – for reasons I’ll explain – declined to comment for this article. But in conversations with meeting invitees, as well as some critics, I’ve found that much of the press coverage was misleading, and says more about the relationship between journalists and scientists than the meeting itself.</p>
<p>What really happened behind closed doors when over 130 scientists, industry leaders and ethicists convened to talk about synthesizing a human genome? How did these sessions end up so widely misunderstood by the media and the public?</p>
<h2>Open doors versus science publishing protocols</h2>
<p>The May 10 meeting was <a href="http://www.nytimes.com/2016/05/14/science/synthetic-human-genome.html">titled</a> “HGP-Write: Testing Large Synthetic Genomes in Cells.” HGP refers to the <a href="https://www.genome.gov/11006943/human-genome-project-completion-frequently-asked-questions/">Human Genome Project</a>, the world’s largest collaborative biological effort that resulted in the sequencing of the full human genome in 2003.</p>
<p>Those invited say the organizers hoped to inspire scientists and the public with a new grand challenge project: to advance from <em>reading</em> genomes to <em>writing</em> them, by manufacturing them from individual DNA building blocks. In an invitation dated March 30, the hosts proposed a bold collaborative effort to “synthesize a complete human genome within a cell line.” Panels tackled whether such an effort is worthwhile, as well as the ethical, technological and economic challenges.</p>
<p>The conversation was not intended to be restricted. The meeting organizers – Harvard geneticist <a href="http://arep.med.harvard.edu/gmc/">George Church</a>; New York University systems geneticist <a href="http://www.med.nyu.edu/research/boeke-lab">Jef Boeke</a>; <a href="http://andrewhessel.com/">Andrew Hessel</a>, of the Bio/Nano research group at <a href="http://www.autodesk.com/">Autodesk, Inc.</a>; and <a href="http://nancyjkelley.com/nancy/">Nancy J. Kelley</a>, a lawyer specializing in biotechnology consulting – had plans to engage the broader scientific community, as well as industry, policy makers and the public. They made a video recording of the entire meeting, originally intended to be live-streamed over the Internet. They planned to apply for federal funding, which would invite regulatory oversight. And they submitted a white paper to a major peer-reviewed journal explaining the scientific, technological and ethical aspects of the project.</p>
<p>But the publication of the paper was delayed – editors commonly ask for revisions as part of the peer review process and Dr. Church told STAT News they wanted “more information about the <a href="https://www.statnews.com/2016/05/13/harvard-meeting-synthetic-genome/">ethical, social, and legal components</a> of synthesizing genomes” included. (As of this writing, the paper has not yet come out.) The organizers are prohibited from discussing the paper in public until it is published – a common <a href="http://www.sciencemag.org/authors/science-editorial-policies">journal</a> <a href="http://www.nature.com/nature/authors/policy/embargo.html">policy</a> known as an embargo. In deference to the embargo, they declined to comment in detail for this article.</p>
<p>News of the delay came just days before the meeting, and, with dozens of attendees en route, the hosts made a fateful decision. They chose to proceed, but to close the doors to most journalists and ask attendees to delay public discussion until the embargo lifts. (At least one journalist was there – Simone Ross, co-founder of <a href="http://techonomy.com">Techonomy Media</a>, confirmed her attendance to me.) “<a href="https://www.statnews.com/2016/05/13/harvard-meeting-synthetic-genome/">I’m not sure that was the best idea</a>,” Dr. Church told STAT News of the decision to proceed out of the public eye.</p>
<p>The secrecy bred suspicion. “Would it be OK to <a href="https://dspace.mit.edu/bitstream/handle/1721.1/102449/ShouldWeGenome.pdf?sequence=1">sequence and then synthesize Einstein’s genome?</a>” asked Stanford bioengineer Drew Endy and Northwestern bioethicist Laurie Zoloth in a joint essay. In theory, an artificial human genome could be used to generate a living human without biological parents. “This idea is an enormous step for the human species, and it shouldn’t be discussed <a href="https://www.statnews.com/2016/05/13/harvard-meeting-synthetic-genome/">only behind closed doors</a>,” STAT News quoted Dr. Zoloth.</p>
<p>Beyond qualms about the science itself, some observers were concerned that the organizers’ decisions - which included seeking industry partners and private funding - were quiet moves towards “<a href="http://www.geneticsandsociety.org/article.php?id=9374">privatiz[ing] the current conversation about heritable genetic modification</a>.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123821/original/image-20160524-25202-1vcfg0q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Like stringing together letters in a printing press, DNA synthesis involves building genes base-by-DNA base.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic.mhtml?id=297675230">Letters via www.shutterstock.com.</a></span>
</figcaption>
</figure>
<h2>The mundane truth about synthetic DNA</h2>
<p>But whether or not the meeting was truly secret is a distraction from its declared main purpose – to discuss the future of DNA synthesis.</p>
<p>The process of making artificial DNA is similar to letterpress printing – each character is painstakingly assembled in the correct order. The result is chemically identical to naturally-occurring DNA. The <a href="http://www.synthesis.cc/2016/05/synthesizing-secret-genomes.html">global market for synthetic DNA</a> is estimated at nearly US$1 billion annually, and does not typically draw much ethical scrutiny. Indeed, both Drs. Church and Endy are co-founders of a DNA synthesis company called <a href="https://www.gen9bio.com/about-us/our-founders">Gen9</a>. </p>
<p>Synthetic DNA is behind promising treatments for <a href="http://www.the-scientist.com/?articles.view/articleNo/42462/title/The-CAR-T-Cell-Race/">cancer</a>, <a href="http://www.health.harvard.edu/blog/pcsk9-inhibitors-a-major-advance-in-cholesterol-lowering-drug-therapy-201503157801">heart disease</a>, <a href="http://doi.org/10.1038/528S8a">HIV</a> and <a href="http://www.theverge.com/2016/4/20/11450262/crispr-base-editing-single-nucleotides-dna-gene-liu-harvard">Alzheimer’s disease</a>. In their invitation, meeting organizers expressed hope that the project would enable “the development of safer, less costly and more effective therapeutics.” Customized cells could be designed to produce biofuels, clean up pollution, or halt the spread of pandemics. Additionally, scientists know that small changes to one’s DNA can majorly influence health, but they have a limited set of tools to study these changes in detail.</p>
<p>The press has largely cheered recent advances in synthesizing DNA. In 2010, J. Craig Venter and his team <a href="http://www.nytimes.com/2010/05/21/science/21cell.html?_r=0">fabricated</a> all 1 million bases of a bacterial genome and transplanted it into a cell. In 2014, meeting organizer Dr. Boeke accomplished the same with <a href="http://doi.org/10.1038/nature.2014.14941">one of the 16 yeast chromosomes</a>; he currently leads a consortium <a href="http://syntheticyeast.org/">trying to synthesize the rest</a>. And the goal of synthesizing a human genome is not new - Mr. Hessel, another organizer, stated <a href="http://www.nytimes.com/2016/05/14/science/synthetic-human-genome.html">his interest in doing so</a> as early as 2012. </p>
<p>And while undoubtedly controversial, meeting conveners say the proposal to make a human genome was intended to inspire a unified vision for the future of synthetic biology, and a plan for addressing the current barriers.</p>
<p>For example, even the genome of a tiny microbe proved to be a steep and costly challenge for Dr. Venter and his team. Creating the synthetic bacterium <a href="http://www.nytimes.com/2010/05/21/science/21cell.html?_r=0">cost over $40 million</a> and required years of work. At current prices, a single human genome would <a href="http://www.nytimes.com/2016/05/14/science/synthetic-human-genome.html">cost $90 million to manufacture</a> – though Dr. Endy predicts that as costs continue to decline, the price tag could drop to $100,000 by 2036.</p>
<p>There is also the issue of manufacturing capacity. Currently, the <a href="http://www.synthesis.cc/2016/03/on-dna-and-transistors.html">entire yearly global production</a> of synthetic DNA would not be enough to print a single human genome.</p>
<p>A major focus of the meeting, say numerous attendees, was to begin to address these technical shortcomings.</p>
<h2>Ethical debate in advance</h2>
<p>Much of the suspicion around the meeting focused on the idea that researchers were hatching clandestine plans to clone human beings via synthetic DNA. And chemically manufacturing the human genome - the set of genetic instructions found in every cell - would truly give new meaning to the term “test-tube baby.” If such a technology existed, any individual’s genome could be decoded and then synthesized on demand by anyone with the know-how.</p>
<p>Ethicists and the news media blew the whistle on what looked to them like scientific hubris.</p>
<p>In their essay, Drs. Endy and Zoloth argue that synthesizing life is “<a href="https://dspace.mit.edu/bitstream/handle/1721.1/102449/ShouldWeGenome.pdf?sequence=1">an enormous moral gesture</a>” which should not be undertaken lightly. And they worry that linking the future of synthetic biology to such a controversial stated goal could jeopardize the entire endeavor. </p>
<p>It makes sense to wrestle with ethical questions well in advance of being confronted with immediate, real-world applications. But at the moment, I’d argue human cloning remains a distant dream.</p>
<p>Importantly, there’s currently no way to transplant an artificial genome into human cells, and even the most impressive achievements - like Dr. Boeke’s yeast project - are hundreds of times smaller in scale than the proposed challenge. It’s not even clear that making a synthetic human cell is worth it. Fabricating the genome of a fruit fly or nematode - <a href="http://www.biology-pages.info/G/GenomeSizes.html">30 times smaller</a> and less ethically fraught than that of a person - could answer many of the same questions. </p>
<p>Scientists could also study human genetics by analyzing people whose DNA already <a href="https://www.washingtonpost.com/national/health-science/genome-news-flash-were-all-a-little-bit-broken/2012/02/15/gIQAyacKIR_story.html?tid=pm_national_pop">contains the desired features</a>, or by using tools to <a href="http://theconversation.com/crispr-cas-gene-editing-technique-holds-great-promise-but-research-moratorium-makes-sense-pending-further-study-43371">edit existing DNA</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/123820/original/image-20160524-25239-1l82yt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Content from scientific meetings is as likely fodder for social media as journal papers.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-344818604/stock-photo-audience-at-a-business-conference-person-taking-photo-with-smart-phone.html">Meeting image via www.shutterstock.com.</a></span>
</figcaption>
</figure>
<h2>Science/journalism symbiosis</h2>
<p>Apart from the scientific questions, the episode highlights the complicated relationship between scientists and the journalists who cover their work. It’s a necessary partnership but one with more than a hint of distrust in both directions.</p>
<p>In a lemons-out-of-lemonade email sent to invitees after the embargo prompted them to close the event to journalists and the public, conference organizers wrote they hoped the decision would allow attendees to “speak freely and candidly without concerns about being misquoted or misinterpreted” – though apparently that wasn’t enough of a concern for them to bar media from the get-go. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"729777013213401088"}"></div></p>
<p>The organizers of the meeting are surely not blameless for the public reception. The decision to respect the embargo was interpreted by the press as suspicious. If one goal of the meeting was to provoke, can the media be blamed for taking notice? And if the meeting was held in private, then isn’t it natural to ask what those in attendance have to hide?</p>
<p>The episode also points to an emerging conflict between social media and traditional science publishing. Research journals move at a glacial pace; nearly all of my colleagues have at at one point waited six months or more to publish. Will the long publication cycle and the <a href="https://theconversation.com/the-logic-of-journal-embargoes-why-we-have-to-wait-for-scientific-news-53677">normally obscure embargo policy</a> be able to adjust to an era when scientific discussions happen at the speed of Twitter?</p>
<p>Researchers must rely on journalists for their communication skills and the audience they reach. And journalists will play a crucial role in facilitating the ethical discussion around synthetic biology – one whose stakeholders include scientists as well as ethicists, policy makers and the broader public – and what the goals and action items of such a debate will be. Critically, a balance must be struck between the watchdog role of the press and the legitimate needs of any profession to carry out some of their discussions in private.</p>
<hr>
<p><em>This article was updated to include the reason why the research journal postponed publication of the HGP-Write group’s paper.</em></p><img src="https://counter.theconversation.com/content/59650/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeff Bessen receives funding from the NIH and HHMI. </span></em></p>A recent closed meeting about building synthetic genomes raised suspicions about just what scientists were planning, away from the public eye.Jeff Bessen, PhD Candidate in Chemical Biology, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/580042016-04-18T15:48:19Z2016-04-18T15:48:19ZLosing your virginity: how we discovered that genes could play a part<figure><img src="https://images.theconversation.com/files/119152/original/image-20160418-1263-1tgrwyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source"> Alex Brylov/Shutterstock</span></span></figcaption></figure><p>As far as big life decisions go, choosing when to lose your virginity or the best time start a family are probably right up there for most people. It may seem that such decisions are mostly driven by social factors, such as whether you’ve met the right partner, social pressure or even your financial situation. But scientists are increasingly realising that such sexual milestones are also influenced by our genes.</p>
<p>In a new study of more than 125,000 people, <a href="http://nature.com/articles/doi:10.1038/ng.3551">published in Nature Genetics</a>, we identified gene variants that affect when we start puberty, lose our virginity and have our first child. This is hugely important as the timing of these events affect educational achievements as well as physical and mental health.</p>
<p>Children can start puberty at <a href="http://www.nhs.uk/Livewell/puberty/Pages/puberty-signs.aspx">any time between eight and 14-years-old</a>. Yet it is only in recent years that we have begun to understand the biological reasons for this. Through studies of both animals and humans, we now know that there’s a complex molecular machinery in the brain that silences <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495948/">puberty hormones</a> until the right time. At this point, chemical messengers secreted from the brain begin a cascade of events, leading to the production of sex hormones and reproductive maturity.</p>
<p>Human genetics studies have identified many genes that are linked to <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=25231870">individual differences in the onset of puberty</a>. There are broadly two approaches used to map such genes – studies of patients affected by rare disorders that affect puberty and large-scale population studies. The former is helpful because it can investigate gene variants that cause extremely early or delayed/absent puberty. </p>
<p>In previous research, we used population studies to survey a large number of individuals using questionnaires and then genome-wide association studies to scan these same participants for common genetic differences. We could then assess whether the participants’ reported age at puberty was related to particular gene variants. In this way, we have in a number of studies identified <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=25231870">more than 100 such variants</a>, each modifying puberty timing by just a few weeks. However, together they contribute substantially. </p>
<p>We now understand that both nature and nurture play a roughly equal role in regulating the timing of puberty. For example, studies have consistently shown that obesity and excessive nutrition in children <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931339/">can cause an early onset of puberty</a>.</p>
<h2>Genetic factors</h2>
<p>However, we know far less about the biological and genetic factors behind the ages that we first have sexual intercourse or have a first child. This is because previous research has focused more on <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=20358457">environmental and family factors</a> than genetics. But the launch of <a href="http://www.ukbiobank.ac.uk/">UK Biobank</a>, a study with over half a million participants, has greatly helped to fill this lack of knowledge. </p>
<p>In our new study, we used this data to survey some 125,000 people in the same way as in the puberty studies. We found 38 gene variants associated with the age of first sexual intercourse. The genes that we identified fall broadly into two groups. One category is genes with known roles in other aspects of reproductive biology and pubertal development, such as the oestrogen receptors, a group of proteins found on cells in the reproductive tract and also in behaviour control centres of the brain.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/119144/original/image-20160418-1238-18hs5mi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119144/original/image-20160418-1238-18hs5mi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119144/original/image-20160418-1238-18hs5mi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119144/original/image-20160418-1238-18hs5mi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119144/original/image-20160418-1238-18hs5mi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119144/original/image-20160418-1238-18hs5mi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119144/original/image-20160418-1238-18hs5mi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">If you went through puberty early you are more likely to have many children in life.</span>
<span class="attribution"><span class="source">Tom Adriaenssen/wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The other group includes genes which play roles in brain development and personality. For example, the gene <a href="http://www.genecards.org/cgi-bin/carddisp.pl?gene=CADM2">CADM2</a>, which controls brain activity and also has strong effects on whether we regard ourselves to be risk-takers. We discovered that this gene was also associated with losing your virginity early and having a higher number of children throughout life. Similarly, the gene <a href="http://www.genecards.org/cgi-bin/carddisp.pl?gene=MSRA">MSRA</a>, linked to how irritable we are, was also associated with age at first sexual intercourse. Specifically, people who are more irritable typically have a later encounter. However, more research is needed to show exactly how these genes help regulate the timing of the reproductive milestones.</p>
<p>We were also able to quantify that around 25% of the variation in these milestones was due to genetic differences rather than other factors.</p>
<h2>Implications for public health</h2>
<p>An important reason why we study reproductive ageing is that these milestones impact reproductive outcomes and also broader health risks. Epidemiological studies show that individuals who go through puberty at younger ages have higher risks of many diseases of old age, such as <a href="https://www.ncbi.nlm.nih.gov/pubmed/26084728">diabetes, heart disease and breast cancer</a>. Similarly, first sexual intercourse at an earlier age is linked to a number of <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=20358457">adverse behavioural, educational and health outcomes</a>. </p>
<p>Using a statistical genetics approach called <a href="http://www.mendelianrandomization.com/index.php">Mendelian Randomisation</a>, a technique that helps clarify the causal relationship between human characteristics, these studies can tell us whether such epidemiological associations are likely to be causal rather than just random associations. We managed to show that early puberty actually contributes to a higher likelihood of risk-taking behaviours, such as sexual intercourse at an earlier age. It was also linked to having children earlier, and having more children throughout life.</p>
<p>These findings, along with previous studies linking early puberty and loss of virginity to social and health risks, back the idea that future public health interventions should aim to help children avoid early puberty, for example by diet and physical activity and avoiding excess weight gain. Our findings predict that this would have benefits both on improving adolescent health and educational outcomes and also for future health at older ages.</p><img src="https://counter.theconversation.com/content/58004/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Perry receives funding from the Medical Research Council (UK)</span></em></p><p class="fine-print"><em><span>Ken Ong receives funding from the Medical Research Council (Unit Programme numbers MC_UU_12015/2). </span></em></p>Study finds that gene linked to risk-taking is associated with losing your virginity early.John Perry, Senior Investigator Scientist, University of CambridgeKen Ong, Group Leader of the Development Programme at the MRC Epidemiology Unit, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/532612016-01-22T15:08:46Z2016-01-22T15:08:46ZCan you turbo-charge your genes to produce ‘designer babies’?<figure><img src="https://images.theconversation.com/files/109007/original/image-20160122-447-1oqoq9b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>If you have bad skin or are losing your hair you might jokingly blame your parents for passing on the genes that cause these problems. Of course, most traits that you’ve inherited probably developed many generations ago. But research is increasingly revealing another level of inheritance at work that really could be down to your parents. </p>
<p><a href="https://theconversation.com/what-a-man-eats-can-affect-his-sperm-and-future-generations-51416">Epigenetics is</a> the study of how our genes can be read differently or turned on or off depending on external factors. It explains why identical twins are not completely identical. With time and age they begin to differ epigenetically, leaving them susceptible to different looks, different diseases and ultimately different causes of death (not including accidents).</p>
<p>Our environment, diet – and even the people we interact with – can alter the epigenetics of the way our genes are expressed. The molecules of our DNA sequence remain the same in each type of cell, but the various epigenetic marks that tell cell proteins how to process certain parts of the DNA can do so in different ways. For example, through one of these mechanisms known as <a href="http://www.news-medical.net/life-sciences/What-is-DNA-Methylation.aspx">DNA methylation</a>, tiny molecules bind to one element of DNA and can potentially shut neighbouring genes down, affecting the cell’s identity. This means that the interpretation of genes is not “fixed” and can be influenced by the environment through epigenetic traits. </p>
<h2>Fitter, happier?</h2>
<p><a href="https://theconversation.com/what-a-man-eats-can-affect-his-sperm-and-future-generations-51416">Some research</a> has even shown that epigenetic changes can be passed on to our children. This raises the question of whether our genes could be improved for the next generations? Could we have taller, fitter and more intelligent children by making changes to our own lives? The simple answer is we don’t yet know. But tantalising studies indicate that the potential is there. Certainly evidence suggests that individuals with unhealthy lifestyles can produce unhealthy children.</p>
<p>One <a href="http://www.fasebj.org/content/early/2013/07/10/fj.12-224048.abstract">2013 study</a>, for example, used two groups of male mice to investigate the effects of parent’s lifestyle on their children and grandchildren. One group of mice was given a high-fat “junk food” diet and the other was fed a controlled, nutritious diet for 10 weeks. All these male mice were then mated with control-fed female mice to produce offspring, who were again mated with control-fed mice to produce a second generation.</p>
<p>The study found the descendants of the “junk food” diet mice were more likely to be obese, even though their own diet was controlled. Studying the sperm of the mice indicated that the cause of this was not mutations in the DNA but epigenetics, the way the genes were expressed. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/109011/original/image-20160122-408-1yt7cv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/109011/original/image-20160122-408-1yt7cv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/109011/original/image-20160122-408-1yt7cv7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/109011/original/image-20160122-408-1yt7cv7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/109011/original/image-20160122-408-1yt7cv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/109011/original/image-20160122-408-1yt7cv7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/109011/original/image-20160122-408-1yt7cv7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Better diet, healthier children?</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>In <a href="http://science.sciencemag.org/content/sci/early/2015/12/29/science.aad7977.full.pdf">another similar study</a>, one group of male mice received a high-fat diet and the other received a normal, healthier diet. The results showed that the offspring of the parents who were fed the healthier diet had reduced glucose intolerance and insulin resistance, which are characteristics for developing diabetes.</p>
<p>These findings suggest that lifestyles and diet of parents can have vital effects on their children and grandchildren. Specifically they suggest poor diets lead to less healthy children, but they also raise the possibility that improving your lifestyle could give your genes the best possible chance of being expressed in a healthy way after they are passed on.</p>
<h2>Genetic remodelling</h2>
<p>Aside from epigenetics, there are other ways you can act that may give your children the best possible genetic headstart. Research shows that the more distantly related you are to your partner, the taller, smarter and more successful at school your children <a href="http://www.nature.com/nature/journal/v523/n7561/full/nature14618.html">are likely to be</a>. However, researchers haven’t yet proved that the greater genetic difference between the parents is the cause of the children’s improved scores or how much of this outcome is down to environmental or other factors.</p>
<p>In the future, we may even see methods emerge for redesigning your DNA to eliminate heritable diseases or make other changes to your genetic make-up. Recently, a powerful gene editing technique <a href="https://theconversation.com/explainer-crispr-technology-brings-precise-genetic-editing-and-raises-ethical-questions-39219">called CRISPR</a> has rapidly progressed. It uses the natural immune defences of bacteria to produce “molecular scissors” that can remove or even replace parts of a DNA sequence with tremendous accuracy. If changes were made to DNA in sperm or egg cells, they could be permanently sealed into the genetic line and passed on to future generations – although just what genes can be successfully altered <a href="https://theconversation.com/forget-about-designer-babies-gene-editing-wont-work-on-complex-traits-like-intelligence-51557">remains to be seen</a>.</p>
<p>However, the notion of editing human embryos (or sex cells) is a controversial region of science and research. There are <a href="https://theconversation.com/crispr-cas-gene-editing-technique-holds-great-promise-but-research-moratorium-makes-sense-pending-further-study-43371">constant debates and discussions</a> around this topic to try to answer the ethical and regulatory questions created by such procedures. While it would be immensely advantageous to treat inherited disorders, if such research were not properly regulated it could be exploited for non-therapeutic alterations and raise the spectre of “<a href="https://theconversation.com/why-the-case-against-designer-babies-falls-apart-45256">designer babies</a>”.</p><img src="https://counter.theconversation.com/content/53261/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ateequllah Hayat does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research on how our lifestyles affect our genes raises the possibility of giving your future kids a better start in life before they’re even born.Ateequllah Hayat, PhD candidate in epigenetics, Queen Mary University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/529182016-01-13T15:07:20Z2016-01-13T15:07:20ZHere’s how genetics helped crack the history of human migration<figure><img src="https://images.theconversation.com/files/108005/original/image-20160113-10444-1bviq6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A family migrating to western US in 1886.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/ooocha/2596003311"> Marion Doss/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Over the past 25 years, scientists have supported the view that modern humans left Africa around 50,000 years ago, spreading to different parts of the world by replacing resident human species like the Neanderthals. However, rapid advances in genetic sequencing have opened up a whole new window into the past, suggesting that human history is much more complicated.</p>
<p>In fact, genetic studies in the last few years have revealed that since our African exodus, humans have moved and mixed a lot more than previously thought – particularly over the last 10,000 years. </p>
<h2>The technology</h2>
<p>Our ability to sequence DNA has increased dramatically since the human genome was first sequenced <a href="http://www.nature.com/nature/journal/v409/n6822/full/409860a0.html">15 years ago</a>. In its most basic form, genetic analysis involves comparing DNA from different sets of people, whether between people with or without a particular type of cancer, or individuals from different regions of the world. </p>
<p>The human genome is 3 billion letters long, but as people differ at just one letter in every thousand, on average, we don’t have to look at them all. Instead, we can compare people where we know there are these differences, known as genetic markers. Millions of these markers have <a href="http://www.nature.com/nature/journal/v467/n7311/abs/nature09298.html">been discovered</a> and, together with a genetic sequencing technology that allows us to cheaply look at these markers in lots of people, there has been an explosion in the data available to geneticists.</p>
<p>But while these analyses have shed light on <a href="https://www.ebi.ac.uk/gwas/">different genetic associations</a>, they have been unable to fully explain the genetic architecture of disease. It is becoming increasingly clear that <a href="http://www.sciencemag.org/content/337/6090/100">rare genetic variants with small effects</a> are likely to play a key role in genetic susceptibility to disease. And, because they are rare, finding these variants requires a whole-genome’s worth of sequence. </p>
<p>For that reason, the last ten years has also seen huge innovation in the technology available to read every letter of a genome. Today’s genome sequencing technologies typically work by breaking up DNA into billions of little pieces and then sequencing each of them separately but simultaneously in order to combine them into a full genome. </p>
<h2>Out of Africa … and back</h2>
<p>In addition to their use in medical genetics, these data are providing us with an increasingly sophisticated view of human history. When living things die, their DNA doesn’t disappear immediately; it slowly degrades over time. This means that the DNA of long dead people can still be found in fossils and skeletons, but it will be have been broken down into small pieces, perfect for modern sequencing technologies.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/107932/original/image-20160112-6977-19qvr80.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/107932/original/image-20160112-6977-19qvr80.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=280&fit=crop&dpr=1 600w, https://images.theconversation.com/files/107932/original/image-20160112-6977-19qvr80.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=280&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/107932/original/image-20160112-6977-19qvr80.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=280&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/107932/original/image-20160112-6977-19qvr80.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=352&fit=crop&dpr=1 754w, https://images.theconversation.com/files/107932/original/image-20160112-6977-19qvr80.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=352&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/107932/original/image-20160112-6977-19qvr80.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=352&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Map of early human migrations. Homo sapiens (red), Neanderthals (yellow-green), early hominids (yellow).</span>
</figcaption>
</figure>
<p>Take the “out of Africa” theory as an example. Based on <a href="http://www.sciencemag.org/content/239/4845/1263">archaeology and limited genetics</a>, the established view was that humans left Africa at some point within the last 100,000 years, spreading out to eventually inhabit the rest of the world, replacing older resident species of humans. While more advanced genetics <a href="http://www.nature.com/nature/journal/v325/n6099/abs/325031a0.html">has confirmed</a> this to be roughly the case, it has also shown that it is not the full story.</p>
<p>Ancient DNA sequenced from fossils has taught us that, following the initial expansion out of Africa, the ancestors of non-Africans lived side-by-side and <a href="http://www.nature.com/nature/journal/v524/n7564/full/nature14558.html">interbred with</a> Neanderthals some 37,000 to 42,000 years ago, <a href="https://theconversation.com/our-fossil-find-suggests-humans-spread-to-asia-way-before-they-got-to-europe-49163">rather than just pushing them out</a>. We also know that the ancestors of some Asian groups interbred with a different group of archaic human – known only from their DNA – called the <a href="http://www.nature.com/nature/journal/v468/n7327/abs/nature09710.html">Denisovans</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/108006/original/image-20160113-10417-yovtrv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/108006/original/image-20160113-10417-yovtrv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=328&fit=crop&dpr=1 600w, https://images.theconversation.com/files/108006/original/image-20160113-10417-yovtrv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=328&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/108006/original/image-20160113-10417-yovtrv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=328&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/108006/original/image-20160113-10417-yovtrv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=412&fit=crop&dpr=1 754w, https://images.theconversation.com/files/108006/original/image-20160113-10417-yovtrv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=412&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/108006/original/image-20160113-10417-yovtrv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=412&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">‘Why you don’t look so bad yourself.’</span>
<span class="attribution"><span class="source">hairymuseummatt/wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Ancient DNA also allows us to directly view the genomes of past populations. For example, we now know that in Europe, the farming revolution some 8,000 years ago was accompanied by the <a href="http://www.nature.com/nature/journal/v513/n7518/full/nature13673.html">movement of people</a> and was not just the spread of a clever idea. There was a subsequent <a href="http://www.nature.com/nature/journal/v522/n7555/abs/nature14317.html">mass migration</a> of people into central Europe from the Russian Steppe which potentially brought Indo-European languages into the continent. A recent <a href="https://theconversation.com/ancient-dna-reveals-how-europeans-developed-light-skin-and-lactose-tolerance-43078">genetic study</a> found that the ability of modern Europeans to digest the lactose in milk into adulthood may be traced to these migrants from Russia. It also traced blue eyes in modern Europeans back to European hunter gatherers of the Mesolithic period (10,000-5,000BC), while light skin may have come from migrants from the Middle East.</p>
<p>Further ancient population mixing happened in Africa when a significant movement of Eurasian people spread back into the continent within the last 3,000 years. In fact, <a href="http://www.sciencemag.org/content/350/6262/820.abstract">one study</a> estimated that between 4-7% of most African genomes may have come from this gene flow.</p>
<p>Analyses of modern-day human populations have shown that a lot of mixing has happened within <a href="http://www.sciencemag.org/content/343/6172/747.full">the last 2,000 years</a>, with populations moving both within and between continents. For example, during their expansions in the 13th century, the Mongols left a trail of DNA across Asia and into <a href="http://www.cell.com/current-biology/abstract/S0960-9822(15)00949-5">Eastern Europe</a>, and towards the end of the first millennium AD, Arabs brought North and West African DNA into <a href="http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1001373">southern Europe</a>. In effect, this means that populations did not extend to the far reaches of the world and remained in isolation. Once settled, these groups continued to share their DNA.</p>
<p>What this tells us is that our history is messy: we are all the product of a tangled bush of genetic relationships between different ancient and modern human groups. Our genes demonstrate that none of us can claim to have ancestry from just a single region or place, as people have been on the move throughout history. Food for thought indeed when migration is so high on the political agenda.</p><img src="https://counter.theconversation.com/content/52918/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>George Busby does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Humans evolved in Africa, spread across the world, and then it gets messy. Luckily advances in genetic sequencing have helped us track the complex history of human migration.George Busby, Research Associate in Statistical Genomics, University of OxfordLicensed as Creative Commons – attribution, no derivatives.