tag:theconversation.com,2011:/us/topics/sundaland-44837/articlesSundaland – The Conversation2019-04-25T09:06:57Ztag:theconversation.com,2011:article/1156282019-04-25T09:06:57Z2019-04-25T09:06:57ZBat and bird poo can tell you a lot about ancient landscapes in Southeast Asia<figure><img src="https://images.theconversation.com/files/270651/original/file-20190424-19272-1559ueh.jpeg?ixlib=rb-1.1.0&rect=28%2C391%2C4716%2C2767&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A bat in a cave among the poo.</span> <span class="attribution"><span class="source">Christopher Wurster</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The islands of Sumatra, Borneo and Java were once part of a much larger landmass connected to Asia called <a href="https://www.worldatlas.com/articles/what-and-where-is-the-sundaland.html">Sundaland</a>. </p>
<p>But there are some species that are unique to each island today – such as the two species of orangutan – so in research, published today in <a href="http://www.nature.com/articles/s41598-019-42670-4" title="Savanna in equatorial Borneo during the late Pleistocene">Scientific Reports</a>, we looked at what could have kept them apart.</p>
<p>And that involves looking at ancient poo samples.</p>
<h2>Land exposed</h2>
<p>Sundaland was largest during times of lowest <a href="https://theconversation.com/sea-level-affected-tropics-in-ice-age-14478">sea level</a>, when it was bigger than all of today’s Europe combined. </p>
<p>Most recently, this was about 20,000 years ago at the peak of the last ice age. Glacial (ice age) periods are much longer than interglacials (warm – like today). </p>
<p>This means <a href="https://www.pnas.org/content/106/27/11188" title="The current refugial rainforests of Sundaland are unrepresentative of their biogeographic past and highly vulnerable to disturbance">Sundaland was exposed above sea level</a> for about 90% of the time over the last few million years, and looked like it does today about 10% of that time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/270360/original/file-20190423-15198-ruo5wj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sundaland when sea level was at its lowest 20,000 years ago. Study sites are shown that support savanna (orange) or rainforest (green) during that time. Also shown are the Molengraf rivers, on the now-submerged shelf, originally identified from early bathymetric surveys in 1921.</span>
</figcaption>
</figure>
<p>But what did the ancient landscapes look like across this vast – now largely underwater – continent? </p>
<h2>Drop what you eat</h2>
<p>To find this out we looked at thick accumulations of bat and bird poo in <a href="https://www.youtube.com/watch?v=0KY3cAmqJ2o">caves across the region</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=248&fit=crop&dpr=1 600w, https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=248&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=248&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=312&fit=crop&dpr=1 754w, https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=312&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/270363/original/file-20190423-15202-s362ws.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=312&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bats flying out of an Indonesian cave for a nightly feed.</span>
<span class="attribution"><span class="source">Chris Wurster</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Insect-feeding bats and birds live in caves. Every night, millions leave their roosts to feed, eating insects from the landscapes surrounding the cave.</p>
<p>After returning to sleep, the bats and birds “do their business”, defecating on the cave floor. The piles of excrement are mostly made up of insect skeletons. So the bats effectively act as mini-scientists, “sampling” the insects that were around the cave during each feed. </p>
<p>Over time, droppings accumulate in deposits several metres thick, which contain insect skeletons many thousands of years old.</p>
<p>Although we can’t identify the insects, as they are too broken up, we can look at <a href="https://www.pnas.org/content/107/36/15664" title="How to sample the carbon isotopes of tropical ecosystems without leaving your armchair">chemical fingerprints</a> to figure out what kind of plants the insects were feeding on. This is because insects that feed on tropical grasses leave a very different chemical imprint to those that feed on trees. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/270369/original/file-20190423-15224-1hujg3q.jpeg?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">Bats clumping on a cave wall: look out below.</span>
<span class="attribution"><span class="source">Chris Wurster</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>So these deposits tell us what type of vegetation was around the cave, and how this changed over time. This is lucky for us, because many other types of records of past environments simply don’t exist in the region, or are now under the sea.</p>
<h2>Rainforest refuges</h2>
<p>Because there aren’t many other sources of information, there is no agreement on what the landscapes were like across Sundaland in the past. </p>
<p>Some argue, and many <a href="https://theconversation.com/sea-level-affected-tropics-in-ice-age-14478">models</a> support this idea, that tropical rainforests always covered the whole region, similar to what exists on the islands today.</p>
<p>But there is another idea: that a savanna cut through Sundaland from north to south. This was flanked east and west by wet tropical rainforest, which served as a refuge for rainforest animals and plants during ice ages.</p>
<p>The whole Indonesian region is a <a href="https://enviroliteracy.org/ecosystems/hotspots-of-biodiversity/sundaland/">biodiversity hotspot</a> with lots of species found only on specific islands and nowhere else. Why? Think of the <a href="https://www.orangutan.org.au/about-orangutans/orangutan-facts/">two species of orangutan</a>, one found only in Sumatra and another only in Borneo. Why are there two subspecies of the <a href="https://animaldiversity.org/accounts/Neofelis_diardi/">Sunda clouded leopard</a>, each unique to Borneo and Sumatra? What about the <a href="https://animaldiversity.org/accounts/Viverricula_indica/">small Indian civet</a>, found on mainland Asia and Java, but mostly absent from Borneo and Sumatra?</p>
<p>This is curious considering that for most of the time these weren’t in fact islands. So how did these species evolve separately if, for most of the time, they should have been able to move freely from Borneo to Sumatra through rainforest?</p>
<p>The answer to this question has implications for the <a href="https://theconversation.com/tigers-confirmed-as-six-subspecies-and-that-is-a-big-deal-for-conservation-105592">conservation</a> of many species in the region.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/270367/original/file-20190423-15227-17jed9a.jpeg?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">Chris, in over his head in cave poo.</span>
<span class="attribution"><span class="source">Hamdi Rifai</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>We need more caves</h2>
<p>We scoured Malaysia and Indonesia for caves with deposits that can answer this question. So what does the cave poo say?</p>
<p>In our latest <a href="http://www.nature.com/articles/s41598-019-42670-4" title="Savanna in equatorial Borneo during the late Pleistocene">published study</a>, we present results from a 3-metre pile of ancient excrement covering almost 40,000 years.</p>
<p>Saleh Cave is on the southeastern end of Borneo and at the southern equatorial end of a savanna corridor, if one existed. Today, lush tropical rainforest covers the region.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/270353/original/file-20190423-15202-gnf9ze.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Being guided to Saleh Cave.</span>
<span class="attribution"><span class="source">Chris Wurster</span></span>
</figcaption>
</figure>
<p>The chemical fingerprint in the cave poo is clear. Tropical grasses were a dominant part of the landscape during the ice age until recently – geologically speaking.</p>
<p>Putting this in the context of our <a href="https://www.pnas.org/content/107/35/15508">earlier work in Malaysia</a>, we conclude that a savanna corridor north of the equator was likely. Or, to put it another way, tropical forests did retreat to refuges on Sumatra and Borneo and did not cover Sundaland during the ice age.</p>
<p>Other ocean records also show that <a href="https://www.nature.com/articles/ngeo2182" title="Indonesian vegetation response to changes in rainfall seasonality over the past 25,000 years">tropical grasses</a> expanded, but these records are well to the south and east, and not in the heart of the proposed savanna corridor. </p>
<h2>A barrier landscape</h2>
<p>The savanna corridor acted as a barrier for rainforest specialists that wanted to move across Sundaland. On the other hand, the savanna corridor served as a bridge for species adapted to the open non-forest environments north and south of the equator.</p>
<p>This <a href="https://sp.lyellcollection.org/content/411/1/235.abstract" title="Barriers and bridges: early human dispersals in equatorial SE Asia">neatly explains</a> many of the odd patterns of animal, insect and bird distributions we see across a region of major significance as a biodiversity hotspot.</p>
<p>It might also partly explain how people managed to move through the region so <a href="https://theconversation.com/how-to-get-to-australia-more-than-50-000-years-ago-96118">rapidly</a> and on into <a href="https://theconversation.com/australias-epic-story-a-tale-of-amazing-people-amazing-creatures-and-rising-seas-115701">Sahul (Australia and New Guinea)</a> – the companion ice age continent to Sundaland – more than 50,000 years ago.</p><img src="https://counter.theconversation.com/content/115628/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher Wurster receives funding from National Geographic Society. </span></em></p><p class="fine-print"><em><span>Michael Bird receives funding from the Australian Research Council. </span></em></p>Ancient poo from bats and birds can tell you what type of vegetation they were feeding on at that time.Christopher Wurster, Senior Research Associate of Stable Isotope Geochemistry, James Cook UniversityMichael Bird, ARC Laureate Fellow, JCU Distinguished Professor, ARC Centre of Excellence for Australian Biodiversity and Heritage, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/858272017-10-17T10:37:08Z2017-10-17T10:37:08ZTracing the origin of Indonesian people through genetics<p><em>To mark <a href="https://www.eventbrite.sg/e/wallace-wallacea-indonesia-wallacea-week-2017-public-lecture-tickets-37719657511">Wallacea Week</a>, a series of public lectures and exhibition on the Wallacea region of Indonesia, The Conversation presents a series of analysis on biodiversity and history of science in Indonesia. This is the third and last article of the series.</em> </p>
<hr>
<p>In Indonesian society, people often use a dichotomy between “pribumi” or native and “pendatang” or migrants. “Pribumi” means the original settlers while “pendatang” are foreigners. This dichotomy often creates racism and tension between groups in the society.</p>
<p>However, a research on human genome found all Indonesians are migrants. Indonesian people are a mix of different genetic groups of <em>Homo sapiens</em> who travelled from Africa in waves spanning tens of thousands years via different routes to the archipelago.</p>
<p>I study the diversity of genetics of Indonesian people. I work with anthropologists, archaeologists, linguists, and computer scientists to reconstruct the history of settlement in the archipelago. In short, I try to learn who are the ancestors of Indonesian people through genetics. </p>
<h2>Tracing migration through genetics</h2>
<p>Before our research, there was no available data about the genetics of humans in Indonesia within the world’s human genome research. Scientists have data about human migration through mainland Asia and Australia, but the data from the Indonesian archipelago were missing because they had never been investigated. </p>
<p>There are three genetic markers that can be used to study human migration.</p>
<p><em>First</em>, the Y chromosome, a protein structure consisting of nucleid acid in sperm cells. Y chromosome inherits DNA from father to children.</p>
<p><em>Second</em>, genetic materials in mitochondria, also called mitochondrial DNA, inherited by mothers to the children. Mitochondria is a structure in cells that transforms food intake into energy in the body.</p>
<p>Human genome researchers categorise humans into genetic populations called haplogroups by looking at the similarities in their Y chromosome or mitochondrial DNA, which are the specific motifs of both DNAs. </p>
<p>The <em>third</em> genetic marker is autosomal DNA, inherited from both parents. </p>
<p>My research colleagues and I in Eijkman Institute collected and analysed around 6,000 samples of DNA from different locations in Indonesia to look at the haplogroups of Indonesian people. We tested more than 3,700 people from 35 ethnic groups for their mitochondrial DNA, and almost 3,000 of them for their chromosome Y. </p>
<h2>The diverse genetic population of Indonesian people</h2>
<p>Using mitocondrial DNA, we found haplogroups M, F, Y2 and B in the western part of Indonesia. The people of these haplogroups are mostly speakers of Austronesia languages, spoken in Southeast Asia, Madagascar and Pacific Islands.</p>
<p>Meanwhile in <a href="https://academic.oup.com/mbe/article/26/8/1865/980671/Genetic-Admixture-History-of-Eastern-Indonesia-as">the eastern part of Indonesia</a> we found haplogroups Q and P. These two haplogroups are unique to people of Papua and Nusa Tenggara. People of haplogroup Q and P are non-Austronesian speakers. </p>
<p>What’s more interesting is Mentawai and Nias, the haplogroup of the people in those islands are grouped with the native people of Formosa, Austronesian speakers who travelled to the south around 5,000 years ago. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/183778/original/file-20170829-10431-g734fu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/183778/original/file-20170829-10431-g734fu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/183778/original/file-20170829-10431-g734fu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/183778/original/file-20170829-10431-g734fu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/183778/original/file-20170829-10431-g734fu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/183778/original/file-20170829-10431-g734fu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/183778/original/file-20170829-10431-g734fu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Mentawai man.</span>
<span class="attribution"><span class="source">www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Came in waves</h2>
<p>Through multidisciplinary research combining genetics research with archaeology and linguistics, we can discover that the ancestors of Indonesian people came in waves. </p>
<p>The history of ancestral migration started 72,000 years ago when a group of <em>Homo sapiens</em> or modern humans travelled south from the African continent to the Arabian peninsula towards India. </p>
<p>The descendants of this first wave of people arrived to what is now the Indonesian archipelago around 50,000 ago. At the time the Malay peninsula, Borneo and Java were still connected as one landmass called Sundaland. Descendants of this group continued to wander to Australia. </p>
<p>Signs that the Indonesian archipelago has been inhabited by modern humans can be seen through archaeological findings. In Sarawak, Malaysia’s territory of Borneo, scientists found <a href="https://theconversation.com/ancient-deep-skull-still-holds-big-surprises-60-years-after-it-was-unearthed-61572">a skull that’s around 34,000 to 46,000 years old</a>. </p>
<p>And in the caves of Maros, South Sulawesi, <a href="https://theconversation.com/40-000-year-old-rock-art-found-in-indonesia-32674">there are 40,000-year-old pre-historic rock arts</a>. </p>
<p>The second migration, around 30,000 years ago, came from the area that is now Vietnam. The third migration is the arrival of Austronesian speakers from Formosa around 5,000 to 6,000 years ago. </p>
<p>Lastly, the spread of Hindu and the rise of the Indian empire between the 3rd to 13th century created a variety of haplogroups found in small frequencies in Bali, Java, Borneo, and Sumatra. There was also the spread of Islam from Arabia and the findings of haplogrup O-M7 which is a marker for people from China. </p>
<h2>Why trace our ancestors?</h2>
<p>By collecting and analysing the genetics data of Indonesians, we can fill the gap of data about human migration between the Asian mainland and the Pacific Islands. </p>
<p>The genetics of Indonesian people are a mix between different groups of humans. Our genetics data shows that the Indonesian archipelago was once a centre of civilisation. </p>
<p>Our research also has provided us with basic information about mutations of specific diseases such as the inherited blood disease <a href="https://id.wikipedia.org/wiki/Talasemia">thalasemia</a>. Thalasemia is the main genetic disease in Indonesia.</p>
<p>By having the data about the mutations, diagnosis can be targeted to ethnic groups where the mutations are most present. This will help doctors and patients deal with diseases and improve health care. </p>
<p>These investigations into genetics that reveal the population structure of Indonesian people, match with the research that found the clustering of human pathogens such as Hepatitis B or C as well as dengue. So, having genetic data can help us fight diseases more effectively. </p>
<p>How about autosomal DNA? This helps us predict the chances of someone to contract certain diseases. It’s always better to prevent than to cure.</p><img src="https://counter.theconversation.com/content/85827/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Herawati Sudoyo tidak bekerja, menjadi konsultan, memiliki saham, atau menerima dana dari perusahaan atau organisasi mana pun yang akan mengambil untung dari artikel ini, dan telah mengungkapkan bahwa ia tidak memiliki afiliasi di luar afiliasi akademis yang telah disebut di atas.</span></em></p>I try to learn who are the ancestors of Indonesian people through genetics. The genetics of Indonesian people are a mix between different groups of humans.Herawati Sudoyo, Deputy for Fundamental Research of Eijkman Institute., Eijkman Institute for Molecular BiologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/856022017-10-15T16:15:51Z2017-10-15T16:15:51ZWallacea: a living laboratory of evolution<figure><img src="https://images.theconversation.com/files/190257/original/file-20171015-3532-1ls3sq5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sulawesi, part of the biogeographical region of Wallacea, is home to tarsiers -- tiny, goggle-eyed creatures look more like mammalian tree frogs than monkeys. </span> <span class="attribution"><span class="source">Ondrej Prosicky/www.shutterstock.com</span></span></figcaption></figure><p><em>To mark <a href="https://www.eventbrite.sg/e/wallace-wallacea-indonesia-wallacea-week-2017-public-lecture-tickets-37719657511">Wallacea Week</a>, a series of public lectures and exhibition on the Wallacea region of Indonesia, The Conversation presents a series of analysis on biodiversity and history of science in Indonesia. This is the first article of the series.</em> </p>
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<p>The central islands of Indonesia - between Java, Bali and Kalimantan (also known as Borneo) on the west and Papua at the eastern end of the country - is a place of wonder, a living laboratory for the study of evolution. </p>
<p>It’s called Wallacea, named after Alfred Russel Wallace, the 19th century English explorer and naturalist. On his exploration in the Indonesian archipelago (then known as the Malay archipelago) Wallace developed his <a href="http://evolution.berkeley.edu/evolibrary/article/history_14">theory of natural selection</a>. </p>
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<img alt="" src="https://images.theconversation.com/files/190258/original/file-20171015-3542-1fak7j5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/190258/original/file-20171015-3542-1fak7j5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=980&fit=crop&dpr=1 600w, https://images.theconversation.com/files/190258/original/file-20171015-3542-1fak7j5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=980&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/190258/original/file-20171015-3542-1fak7j5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=980&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/190258/original/file-20171015-3542-1fak7j5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1231&fit=crop&dpr=1 754w, https://images.theconversation.com/files/190258/original/file-20171015-3542-1fak7j5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1231&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/190258/original/file-20171015-3542-1fak7j5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1231&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">Alfred Russel Wallace.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
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<p>He noticed that the islands of Kalimantan and Sulawesi as well as Bali and Lombok have very distinct animals even though the islands are next to each other. He proposed an invisible line runs between Kalimantan and Sulawesi and Bali and Lombok separating the faunas. </p>
<p>In Kalimantan and Bali live animals such as tiger, rhinos and elephants, which now, due to human population expansion, are endangered. In Sulawesi and Lombok to the east of the small Mollucas islands, we find marsupials, a variety of peculiar looking monkeys, and interesting endemic animals. Endemic animals means they are native or restricted to an area. </p>
<p>The invisible line is now known as Wallace’s Line and the region between it and the island of New Guinea has come to be called Wallacea. </p>
<p>Scientists today know that Kalimantan and Bali were connected as part of <a href="https://www.newscientist.com/article/mg16021657-200-where-it-all-began/">Sundaland</a>, a large landmass that includes the Malay Peninsula on the Asian mainland as well as Java and Sumatra. This landmass was exposed for 2.6 million years until ice caps started to melt around 14,000 years ago, submerging part of the landmass and creating the Indonesian archipelago.</p>
<h2>Creatures of Wallacea</h2>
<p>Wallacea includes the large island of Sulawesi, the Mollucas - the various small to medium-sized islands to the east of Sulawesi and the “Banda Arc” islands - and the Lesser Sundas or Nusa Tenggara, south of Sulawesi and the Moluccas. </p>
<p>Wallacea is a transition zone between the great Indo-Malayan and Australasian biogeographical realms. Millions of years of relative geographical isolation have allowed fascinating and highly endemic fauna to evolve here. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/190261/original/file-20171015-3545-8w6sus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/190261/original/file-20171015-3545-8w6sus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=583&fit=crop&dpr=1 600w, https://images.theconversation.com/files/190261/original/file-20171015-3545-8w6sus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=583&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/190261/original/file-20171015-3545-8w6sus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=583&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/190261/original/file-20171015-3545-8w6sus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=733&fit=crop&dpr=1 754w, https://images.theconversation.com/files/190261/original/file-20171015-3545-8w6sus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=733&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/190261/original/file-20171015-3545-8w6sus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=733&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Wallacea.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Wallacea_Hotspot_2005_Print.tif">Conservation International/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Wallacea is home to <a href="http://www.bird-stamps.org/books/77.htm">697 bird species</a>, of which 249 (36%) are endemic. The rate of endemism rises to a more impressive 44% if only the resident birds, or those that don’t migrate, are considered. </p>
<p>On Sulawesi and its satellite islands, there are 328 bird species, 230 of them resident and 97 species are endemic, among them the maleo bird. </p>
<p>Wallacea has a total of 201 native mammal species (excluding whales and dolphins), 123 of which are endemic. If we exclude the 81 bat species with their greater capacity for dispersion, the rate of endemism increases to a very high 93%.</p>
<p>Sulawesi, the largest island in Wallacea, has the highest number of mammals, with 132 species, of which 83 (63%) are endemic. </p>
<p>It holds important flagship species such as the anoas (<em>Bubalus depressicornis</em>), diminutive buffaloes that live in the forests of Sulawesi, and the babirusa (<em>Babyrousa babyrussa</em>), an unusual, enigmatic pig with long, recurved upper tusks that penetrate through the skin of the upper lip. </p>
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<img alt="" src="https://images.theconversation.com/files/190264/original/file-20171015-3520-le1zbm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/190264/original/file-20171015-3520-le1zbm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/190264/original/file-20171015-3520-le1zbm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/190264/original/file-20171015-3520-le1zbm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/190264/original/file-20171015-3520-le1zbm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/190264/original/file-20171015-3520-le1zbm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/190264/original/file-20171015-3520-le1zbm.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 enigmatic pig of Sulawesi, babirusa.</span>
<span class="attribution"><span class="source">Artush/www.shutterstock.com</span></span>
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</figure>
<p>Sulawesi’s primates are also special. At least seven species of macaques are unique to the island. Sulawesi also has several species of tarsiers - tiny, goggle-eyed creatures that look more like mammalian tree frogs than monkeys. </p>
<p>Reptile diversity is also quite high, with 188 species, of which 122 (65%) are endemic. The best known reptile in Wallacea, and one of Indonesia’s most famous species, is the Komodo dragon (<em>Varanus komodoensis</em>) or “<em>ora</em>” in local language. </p>
<p>Komodo is the heaviest lizard in the world (males can reach about 2.8 m in length and weigh about 50 kg). They live only in the tiny island of Komodo, the neighbouring islands of Padar and Rinca to the west, and the western end and north coast of Flores. </p>
<p>Most of the 210 freshwater fish species recorded from the rivers and lakes in Wallacea are tolerant of both fresh and salt water to some extent. </p>
<p>We still need more research in fish species. In the Moluccas and Lesser Sundas, the fish fauna is poorly known. But there appear to be around six island endemics. On Sulawesi, there are 69 known species, of which 53 (77%) are endemic. </p>
<p>At the northeastern corner of South Sulawesi lies the Malili Lakes, a complex of deep lakes, rapids and rivers. Here, at least 15 endemic beautiful <a href="https://en.wikipedia.org/wiki/Telmatherinidae">telmatherinid</a> fishes have evolved. </p>
<p>The plants of Wallacea is not as well known as that of its neighbours. Fewer botanical specimens per-unit-area are collected than on any other major islands in Indonesia. </p>
<p>We also don’t know much of the invertebrate fauna of Wallacea. However, some groups, such as the enormous birdwing butterflies are better known. </p>
<p>Wallacea also has the world’s largest bee (<em>Chalocodoma pluto</em>) in the northern Moluccas. The females can grow to 4 cm in length. They are also remarkable because they nest communally in inhabited termite nests in lowland forest trees.</p>
<h2>Human impact</h2>
<p>As elsewhere, things have changed dramatically in Wallacea during the course of the past century. The human population has nearly quadrupled. Development has grown tremendously in Indonesia in general. </p>
<p>The first commercial logging operation in Wallacea began in the early part of the century, and forests have been cleared for agricultural programs, for industrial timber plantations, and for land settlement schemes that resettled hundreds of thousands of people from densely populated Java to other less inhabited (but much less productive) corners of Indonesia. </p>
<p>This has greatly reduced the amount of forest habitat, particularly in the lowlands, and has caused dramatic and severe declines in the populations of many forest species (many as much as 90%). </p>
<p>Much of the remaining forest is now given out in timber concessions of various kinds. </p>
<p>Furthermore, forest and land fires continues to be a problem. It is now greatly exacerbated by increased drying because of logging and plantation agriculture, and sometimes by intentional burning as well.</p>
<p>Overall, about 45% of Wallacea still has some forest cover; however, if one considers forest that is still in more or less pristine condition, the percentage drops to only 15%, or about 50,774 square kilometer.</p>
<p>At this point in time, forest protection in Wallacea is moderate at best. Protected area coverage is around 24,387 square kilometer, or 7% of original extent. </p>
<p>Of course, establishment of protected areas is only a beginning. Once created, they need management and the cooperation of local people, the government, and the private sector in order to be successful in conserving biodiversity. For millions of years, fascinating creatures have managed to diversify and evolve over millions of years. We have a moral obligation to protect this wonder.</p><img src="https://counter.theconversation.com/content/85602/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jatna Supriatna is a member of the Indonesian Academy of Sciences (AIPI) and sits in the governing board of Yayasan The Conversation Indonesia. </span></em></p>The central islands of Indonesia, also known as Wallacea, is a place of wonder, a living laboratory for the study of evolution.Jatna Supriatna, Professor of Conservation Biology, Universitas IndonesiaLicensed as Creative Commons – attribution, no derivatives.