tag:theconversation.com,2011:/ca/topics/prehistoric-civilisations-4440/articlesprehistoric civilisations – The Conversation2018-03-01T16:47:39Ztag:theconversation.com,2011:article/925462018-03-01T16:47:39Z2018-03-01T16:47:39ZHuman ancestors had the same dental problems as us – even without fizzy drinks and sweets<figure><img src="https://images.theconversation.com/files/208468/original/file-20180301-152552-1m1hj72.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Teeth fossils with evidence of dental lesions from _Australopithecus africanus_.</span> <span class="attribution"><span class="source">Ian Towle</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Dental erosion is one of the most common tooth problems in the world today. Fizzy drinks, fruit juice, wine, and other <a href="http://www.bbc.co.uk/news/health-43141587">acidic food and drink</a> are usually to blame, although perhaps surprisingly the way we <a href="https://www.karger.com/Article/Abstract/359936">clean our teeth also plays a role</a>. This all makes it sound like a rather modern issue. But research suggests actually humans have been suffering dental erosion for millions of years. </p>
<p>My colleagues and I have discovered dental lesions remarkably similar to those caused by modern erosion on two 2.5m year-old front teeth from one of our <a href="http://humanorigins.si.edu/evidence/human-fossils/species/australopithecus-africanus">extinct ancestors</a>. This adds to the evidence that prehistoric humans and their predecessors suffered surprisingly similar dental problems to ourselves, despite our very different diets.</p>
<p>Dental erosion can affect all dental tissue and typically leaves shallow, shiny, lesions in the enamel and root surface. If you brush your teeth too vigorously you can weaken dental tissue, which over time allows acidic foods and drinks to create deep holes known as non-carious cervical lesions (NCCLs).</p>
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<img alt="" src="https://images.theconversation.com/files/208469/original/file-20180301-152564-17d89g0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208469/original/file-20180301-152564-17d89g0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208469/original/file-20180301-152564-17d89g0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208469/original/file-20180301-152564-17d89g0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208469/original/file-20180301-152564-17d89g0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=400&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208469/original/file-20180301-152564-17d89g0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=400&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208469/original/file-20180301-152564-17d89g0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=400&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"><em>Australopithecus africanus</em> teeth with lesions.</span>
<span class="attribution"><span class="source">Ian Towle</span>, <span class="license">Author provided</span></span>
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<p><a href="https://www.sciencedirect.com/science/article/pii/S1879981717301766">We found such lesions</a> on the fossilised teeth from a human ancestor species <em>Australopithecus africanus</em>. Given the lesions’ size and position, this individual would likely have had toothache or sensitivity. So why did this prehistoric hominin have tooth problems that look indistinguishable from that caused by drinking large volumes of fizzy drinks today?</p>
<p>The answer may come back to another unlikely parallel. Erosive wear today is often also associated with aggressive tooth brushing. <em>Australopithecus africanus</em> probably experienced similar dental abrasion from eating tough and fibrous foods. For lesions to form, they would still have needed a diet high in acidic foods. Instead of fizzy drinks, this probably came in the form of citrus fruits and acidic vegetables. For example, tubers (potatoes and the like) are tough to eat and some can be surprisingly acidic, so they could have been a cause of the lesions.</p>
<p>Dental erosion is extremely rare in the fossil record, although this might be because researchers haven’t thought to look for evidence of it until now. But another type of problem, carious lesions or cavities, has been found more often in fossilised teeth.</p>
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<figcaption>
<span class="caption">Carious lesions on the mandibular right second premolar and first molar. Homo naledi (UW 101-001).</span>
<span class="attribution"><span class="source">Ian Towle</span></span>
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<p>Cavities are the most common cause of toothache today and are caused by consuming starchy or sugary food and drink including grains. They are <a href="https://askthedentist.com/paleo-diet-oral-health/">often considered</a> a relatively modern problem linked to the fact that the invention of farming introduced large amounts of carbohydrates, and more recently refined sugar, to our diets. </p>
<p>But recent research suggests this is not the case. In fact, cavities <a href="https://www.sciencedirect.com/science/article/pii/000399699090185D">have now been found</a> in tooth fossils from nearly every prehistoric hominin species studied. They were probably caused by eating certain fruits and vegetation as well as honey. These lesions were often severe, as in the case of cavities found on the teeth of the <a href="https://theconversation.com/homo-naledi-fossil-discovery-a-triumph-for-open-access-and-education-47726">newly discovered species</a>, <em>Homo naledi</em>. In fact, these cavities <a href="https://www.researchgate.net/publication/320042869_Dental_pathology_wear_and_developmental_defects_in_fossil_hominins_and_extant_primates">were so deep</a> they probably took years to form and would almost certainly have caused serious toothache.</p>
<h2>Dental abrasion</h2>
<p>Another striking type of dental wear is also more common in the fossil record, and again we can guess how and why it was created by looking at the teeth of people alive today. This process, called dental abrasion, is caused by repeatedly rubbing or holding a hard item against a tooth. It could come from biting your nails, smoking a pipe or holding a sewing needle between your teeth. These activities usually take years to form noticeable notches and grooves, so when we find such holes in fossilised teeth they offer fascinating insights into behaviour and culture.</p>
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<figcaption>
<span class="caption">Example of a notch from a clay pipe (17th century set of teeth).</span>
<span class="attribution"><a class="source" href="https://newsdesk.si.edu/photos/wear-and-tear-clay-pipe">Chip Clark, Smithsonian Institute</a></span>
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<p>The best examples of this type of prehistoric dental wear are “toothpick grooves”, thought to be caused by repeatedly placing an object in the mouth, <a href="https://www.smithsonianmag.com/smart-news/neanderthals-used-toothpicks-treat-aching-teeth-180963883/">usually in the gaps between the back teeth</a>. The presence of <a href="http://onlinelibrary.wiley.com/doi/10.1002/ajpa.23166/full">microscopic scratches around these grooves</a> suggests they are examples of prehistoric dental hygiene, where the individual has used stick or other implements used to dislodge food. Some of these grooves are found on the same teeth as cavities and other dental problems, suggesting they may also be evidence of people trying to relieve their toothache.</p>
<p>These lesions have been found in a <a href="https://www.sciencedirect.com/science/article/pii/S1040618214001451">variety of hominin species</a>, including prehistoric humans and Neanderthals, but only in the species most closely related to us, not our older ancestors. This might mean this tooth wear is the result of more complex behaviour from species with larger brains. But more likely it’s a consequence of different diets and cultural habits.</p>
<p>What we do know for sure is that the complex and severe dental problems we often associate with a modern diet of processed foods and refined sugars actually existed far back into our ancestry, although less frequently. Further research will likely show that lesions were more common than previously thought in our ancestors, and ultimately will provide more information into the diet and cultural practices of our distant fossil relatives.</p><img src="https://counter.theconversation.com/content/92546/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Towle 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>Prehistoric humans and their predecessors may have had a very different diet but their teeth suffered in similar ways to ours.Ian Towle, Sessional Lecturer in Anthropology, Liverpool John Moores UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/519622015-12-11T12:09:23Z2015-12-11T12:09:23ZStonehenge isn’t the only prehistoric monument that’s been moved – but it’s still unique<figure><img src="https://images.theconversation.com/files/104843/original/image-20151208-32398-1aam1dr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Stonehenge</span> </figcaption></figure><p>I led the team of researchers that <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10057091&fulltextType=RA&fileId=S0003598X15001775">discovered</a> that Stonehenge was most likely to have been originally built in Pembrokeshire, Wales, before it was taken apart and transported some 180 miles to Wiltshire, England. It may sound like an impossible task without modern technology, but it wouldn’t have been the first time prehistoric Europeans managed to move a monument.</p>
<p>Archaeologists are increasingly discovering megaliths across the continent – albeit a small number so far – that were previously put up in earlier monuments. </p>
<h2>Other ‘second-hand’ monuments</h2>
<p>The best example of such a structure outside the UK is La Table des Marchand, a Neolithic tomb in Brittany, France, built around 4000BC. The enormous, 65-ton capstone on top of its chamber is a broken fragment of a menhir, a standing stone, brought from 10km away. The original menhir may be 300 years (or more) older than the tomb. Another fragment of this same menhir was incorporated into a tomb at Gavrinis, 5km away. This menhir, originally weighing over 100 tons, is actually one of the largest blocks of stone that we know of to have been moved and set up by Neolithic people. </p>
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<img alt="" src="https://images.theconversation.com/files/104847/original/image-20151208-32378-ldiy9w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/104847/original/image-20151208-32378-ldiy9w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/104847/original/image-20151208-32378-ldiy9w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/104847/original/image-20151208-32378-ldiy9w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/104847/original/image-20151208-32378-ldiy9w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/104847/original/image-20151208-32378-ldiy9w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/104847/original/image-20151208-32378-ldiy9w.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">La Table des Marchand.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Cairn_Table_des_Marchand_Locmariaquer.jpg">Myrabella/wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Another example of a standing stone reused in a megalithic monument is an anthropomorphic menhir – a standing stone carved in the form of a human figure - incorporated as the capstone of <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10037964&fulltextType=RA&fileId=S0079497X15000031">another tomb</a> at Déhus on Guernsey. Another megalithic tomb, La Motte de la Jacquille in western France, is built of dressed stones that have been rearranged into a new tomb but it is not known if they came from a different location or were an earlier version of the tomb rebuilt on the same spot.</p>
<p>Archaeologists have known for many years that some of Stonehenge’s bluestones (the shorter stones in the monument) <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10037955&fulltextType=RA&fileId=S0079497X1500002X">were reused</a>. Two are lintels reused as standing stones, and two others have vertical grooves that show they were part of a wall of interlocking standing stones. Until now it was thought that these were evidence of reuse just within Stonehenge which was first built around 2900BC and rebuilt circa 2500BC (at this point, large local sandstones known as “sarsen” were erected). It was then rebuilt again in around 2400BC and 2200BC.</p>
<p>However, we identified the actual quarries in Pembrokeshire, Wales (around 3400BC and 3200BC) that the bluestones came from. This is a period before prehistoric people were building stone circles (normally dating from 3000BC onwards) so we also think it is very likely that the bluestones originally formed a rather different type of monument from a stone circle. </p>
<p>People in western Britain and Ireland at this time were building Neolithic stone tombs known as passage tombs – <a href="http://www.newgrange.com/">Newgrange in Ireland</a> is the best known example. So it is just possible that there is a dismantled passage tomb somewhere near the bluestone quarries. That’s what we will be looking for in 2016.</p>
<h2>Stonehenge – an unusual distance</h2>
<p>An interesting outcome from a recent conference in Redondo, Portugal, on prehistoric megaliths and “second-hand monuments” is that – while some megalithic stones for monuments in Portugal and elsewhere were brought <a href="http://adsabs.harvard.edu/abs/2012EGUGA..1413128B">as far as 8km from their sources</a> – the vast majority of Neolithic stone monuments throughout Western Europe were built less than 2km to 3km away from their stone quarries. So Stonehenge is a major exception to this rule, as its bluestones were dragged around 290km. This makes it unique for prehistoric Europe.</p>
<p>How the stones were moved from Wales to Stonehenge is something of a mystery but our excavations at one of the Welsh quarries reveals that the trackway leading from the outcrop was too narrow for rollers to have been used. Instead, we think that monoliths were loaded onto wooden sledges and dragged over logs and branches laid rail-like in front of the sledge. </p>
<p>Some archaeologists have speculated that Stonehenge’s bluestones must have been thought to have had special properties – as <a href="http://www.theguardian.com/culture/shortcuts/2014/mar/05/stonehenge-built-rock-music-bluestones-acoustic">musical “gongs”</a> or <a href="http://www.bbc.co.uk/history/ancient/british_prehistory/healing_stones.shtml">healing stones</a> – for them to have been sought out from so far away. </p>
<p>But we think it is far more likely that the bluestones were derived from quarries in close proximity to each other – within 2km to 3km – and brought together to build a local monument in Pembrokeshire. Scientific analysis of <a href="http://education.jlab.org/itselemental/ele038.html">strontium</a> isotopes in the teeth of people buried in the Stonehenge area reveals that many of them have values consistent with growing up in western Britain. So the stones may have been brought by people migrating from Wales, bringing their ancestral monument as a symbol of their history and identity. Strontium isotope analysis is currently being carried out on the people actually buried at Stonehenge when the bluestones were erected, and we await the results to see if they show a similar picture.</p>
<p>It’s also possible that the bluestones were put up somewhere on Salisbury Plain before they arrived at Stonehenge. For example, one of the bluestones never quite made it to Stonehenge and was dug out in 1801 from the top layer of a Neolithic burial mound called <a href="http://www.themodernantiquarian.com/site/1980/boles_barrow.html">Boles Barrow, near Warminster</a>, also in Wiltshire. </p>
<p>Although this tomb was first built around 3700BC, it seems to have gone through modifications, of which adding a layer of large stones (mostly local sarsen stones and this one bluestone) happened at the end of its use. So we don’t know precisely when it got there but it may have been set up as a burial marker before the rest of the bluestones were erected at Stonehenge.</p>
<p>Rebuilding tombs and other megalithic structures as second-hand monuments is only now turning out to be recognised in various parts of western Europe as archaeologists start to look more closely at the detailed aspects of construction. Simple expediency of finding suitable stone does not explain sites such as Stonehenge and the Table des Marchand – they were most likely incorporating aspects of the past which had rich historical resonance for them.</p><img src="https://counter.theconversation.com/content/51962/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Parker Pearson receives funding from National Geographic Society</span></em></p>Piecing together how Stonehenge came to be reveals similarities and differences with other monuments of the time.Mike Parker Pearson, Professor of Archaeology, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/282322014-06-20T05:05:32Z2014-06-20T05:05:32ZPrehistoric parasite egg suggests early disease spread through human technology<figure><img src="https://images.theconversation.com/files/51677/original/wfkn9zp3-1403189497.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Unless you're a schistosomiasis parasite.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/dcmetroblogger/3072981794/sizes/l/in/photolist-5FxQqJ-bMX6Gr-bvpXKQ-ifrREz-bvpXzQ-8X2S4t-hftWMq-3mcFz1-6mT3hk-9beWar-9beW5v-i5Kxzw-agQij-bpcjje-5WsyUB-BwZF8-9beW1g-4qXiex-bWeBJu-8e99yj-Syj4p-bvpXx7-7GSFSH-7GSFUn-7GSFRH-7GWBYW-7PWNqR-emEnvU-bqiKcw-bnLSsY-emqGTP-ajpw6P-emqHLc-mjp6xU-bAFJbP-6HTbT8-6JMd2f-6HXhYy-8zoyqG-6HTbAH-9phzuH-bvpXN7-4Wjjbp-3mcFtS-ifpAuR-ifsdQR-6VUvax-6VUvag-63pvB4-mKiqNF-bs82Hg/">Wayan Vota</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>We are used to the idea that modern technological inventions can have unforeseen consequences on health. Infamous examples include the anti-nausea drug thalidomide, which caused <a href="http://toxsci.oxfordjournals.org/content/122/1/1.full">limb defects in unborn babies</a>, and the pesticide DDT, which led to poorly formed egg shells in birds of prey <a href="http://www.stanford.edu/group/stanfordbirds/text/essays/DDT_and_Birds.html">and a crash in the population</a>. Another example in recent history is Marie Curie and her colleagues who developed bone marrow failure or cancer after discovering radiation and developing X-ray imaging. However, much less is known about the earliest time periods and the impact of new man-made technologies. </p>
<p>In new research <a href="http://bit.ly/UQtT84">published in The Lancet Infectious Diseases</a>, we investigated the parasites present in 26 prehistoric burials of people living <a href="http://www.nytimes.com/2010/04/06/science/06archeo.html?pagewanted=all&_r=0">at the site of Tell Zeidan</a>, an early farming settlement located on the confluence of the Balikh and Euphrates rivers in northern Syria, which dates from between 7,800 to 6,000 years ago. The burials studied date from about 6,200 years ago.</p>
<p>In one individual, we found the egg of a terminal spined schistosome, which is a flatworm parasite <a href="http://www.cdc.gov/parasites/schistosomiasis/">that causes schistosomiasis</a>, also called bilharzia.</p>
<p>We analysed soil samples from the pelvic area in front of the sacrum bone, where the abdominal organs would have been as they decomposed. Control samples were also taken from the head and feet of these burials, where no abdominal parasites would have been during life and these showed negative for parasite eggs, showing that the soil had not been contaminated by the later use of the area as a toilet.</p>
<p>The disease is spread by people wading or swimming in warm, slow moving, fresh water. These sources of water are colonised by water snails that can then act as an intermediate host for the parasite. When people are in the water, the parasites leave the snails and burrow through the human skin. They then migrate to the blood vessels in the abdomen where they grow, mate and produce eggs. </p>
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<a href="https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/51680/original/vxy6kgvw-1403191485.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&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">Schistosoma parasite worm.</span>
<span class="attribution"><a class="source" href="http://en.wikipedia.org/wiki/Schistosoma#mediaviewer/File:Schistosoma_20041-300.jpg">David Williams</a></span>
</figcaption>
</figure>
<p>There are different species of schistosomiasis parasites, with some choosing the blood vessels of the bladder, and others the blood vessels of the intestines. These parasites have severe consequences as blood loss into the bladder or intestines results in marked anaemia and so reduce the ability to undertake physical work. Long-term infection with <em>S. haematobium</em> can also trigger bladder cancer.</p>
<p>In modern times, the two species of schistosome whose eggs most closely match the shape of the prehistoric egg are <em>S. haematobium</em> and <em>S. intercalatum</em>. While the first of these is found in the Middle East today, <em>S. intercalatum</em> is only found in west Africa. That means either this parasite is an <em>S. haematobium</em>, or the region in which <em>S. intercalatum</em> was endemic in the past was once very much larger and included the Middle East.</p>
<h2>A role for man-made technology</h2>
<p>This discovery is also particularly fascinating as in modern times in regions such as Africa, schistosomiasis is commonly spread by man-made irrigation technology such as water channels and reservoirs used to irrigate crops. If a new dam is built, frequently schistosomiasis moves into the region within a few years. The snail eggs can be transmitted on the feet of birds, and the parasite spread by infected travellers going to the toilet in or near to water sources. More than 200m people in the world <a href="http://www.who.int/schistosomiasis/en/">are infected with schistosomiasis today</a>.</p>
<p>Water irrigation technology was first invented in the world about 7,500 years ago, in the region of the Middle East between the Euphrates and Tigris river systems known as Mesopotamia. Different techniques are thought to have been used, including facilitating the flooding of fields with river water, and moving water to the fields in man made channels. At Tell Zeidan, the archaeologists believe crop irrigation of some kind was in use as they have found evidence for crops such as wheat and barley that require more water to grow than could be obtained from rainfall alone at the time the settlement was in use. Research into prehistoric rainfall in the region suggests it was just too arid to grow these crops there without extra water.</p>
<p>We will never know if the prehistoric individual at Tell Zeidan caught the infection from wading or swimming in a natural water source, or if it was from wading in an agricultural irrigation system. But the presence of schistosomiasis at this early time, in the centuries following the invention of crop irrigation in the region, does show that it could easily have been spread that way, and that early irrigation could have facilitated the spread of the disease across the region.</p>
<p>The later Assyrian culture flourished in Mesopotamia from 4,500 years ago, and their medical texts include descriptions of red urine. Since <em>S. haematobium</em> causes blood loss in the urine, this early textual evidence provides further support for the identification of schistosomiasis in the region. People at the time would have seen the benefits of their crop irrigation on the amount of food they could grow, and also the types of plants they could cultivate. However, they would have had no idea that the new technology would lead to huge numbers of people across the world contracting schistosomiasis over the following 6,000 years.</p><img src="https://counter.theconversation.com/content/28232/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Piers Mitchell 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>We are used to the idea that modern technological inventions can have unforeseen consequences on health. Infamous examples include the anti-nausea drug thalidomide, which caused limb defects in unborn…Piers Mitchell, Affiliated Lecturer in Biological Anthropology, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.