tag:theconversation.com,2011:/us/topics/dragonflies-4506/articlesDragonflies – The Conversation2018-09-02T18:20:27Ztag:theconversation.com,2011:article/1023842018-09-02T18:20:27Z2018-09-02T18:20:27ZAre the Paleozoic era’s giant dragonflies still among us?<figure><img src="https://images.theconversation.com/files/234118/original/file-20180829-195319-1d4y13t.jpg?ixlib=rb-1.1.0&rect=0%2C7%2C1200%2C790&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">3D model of _Meganeura monyi_.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Don’t worry. This isn’t an announcement of a new invasion from elsewhere, but a leap into the past in the <a href="https://en.wikipedia.org/wiki/Paleozoic">Paleozoic</a>: the time of giant insects, 100 million years before the dinosaurs, during which insects also had their T-Rex: Carboniferous and Permian giant dragonflies that terrorised the skies of those times, sometimes call “griffenflies”). A short trip back in time to a kind of another Earth in search of insects that were already major actors of the ecosystems.</p>
<h2><em>Meganeura</em>, a star of the French Museum collection</h2>
<p>This unique specimen in the world is a giant dragonfly that lived 300 million years ago in the huge equatorial warm forests that at the time covered the center of France. It was almost 40 cm long and 70 cm wingspan. It is one of the largest known insects.</p>
<p>During the <a href="https://en.wikipedia.org/wiki/Carboniferous">Carboniferous</a> (from 360 to 299 million years ago), other insects were also very large, such as cockroaches (Dictyoptera) and Palaeodictyoptera. This gigantism has long been explained by the high percentage of oxygen in the air (twice the current level, i.e., nearly 40%) which would have favoured the physiology of flight during this period. Explanations based on ecological factors more related to the absence of flying predatory vertebrates at this time would explain these large insect sizes. A combination of both phenomena should be considered.</p>
<p>For many millions of years, during Carboniferous, large quantities of plant debris accumulated in shallow waters. Their burial, protected from the air by the sediments that contained them, contributed to the formation of very fossiliferous layers of coals.</p>
<p><em>Meganeura</em> was described and named by Charles Brongniart in 1885, shortly after its discovery. This dragonfly from the depths of time is the emblem of the city of Commentry in the Auvergne region, the former mining town where it was found. It was long emblematic of the giant insects of the Palaeozoic, remaining the largest known insect until the discovery of a Meganeuridae in the United States in the middle of the 20th century, which are a few centimeters larger.</p>
<h2>Were giant dragonflies the Paleozoic’s “hawks”?</h2>
<p>While re-examining one of the fossils of the French Museum’s collections, we have been able to go further in the interpretation of the morphology of these organisms.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/233674/original/file-20180827-75993-1esv3j8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/233674/original/file-20180827-75993-1esv3j8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=553&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233674/original/file-20180827-75993-1esv3j8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=553&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233674/original/file-20180827-75993-1esv3j8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=553&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233674/original/file-20180827-75993-1esv3j8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=695&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233674/original/file-20180827-75993-1esv3j8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=695&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233674/original/file-20180827-75993-1esv3j8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=695&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fossil of a <em>Meganeurites gracilipes</em>.</span>
<span class="attribution"><span class="source">MNHM</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Comparing them to the current dragonflies, whose hunting techniques split into two main types: those that hunt at post (perched) and those that hunt in flight (like hawks), we can attribute this fossil to the category of hunters in flight. Indeed, large and contiguous eyes, with a field of vision of nearly 360°, a vision upwards and downwards, solid legs with spikes to seize prey, are the characteristics of dragonfly “hawks”.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/233675/original/file-20180827-76003-198nvhb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/233675/original/file-20180827-76003-198nvhb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=533&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233675/original/file-20180827-76003-198nvhb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=533&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233675/original/file-20180827-76003-198nvhb.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=533&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233675/original/file-20180827-76003-198nvhb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=670&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233675/original/file-20180827-76003-198nvhb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=670&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233675/original/file-20180827-76003-198nvhb.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=670&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Head of the dragonfly <em>Gynacantha sp.</em> (Guyane), an example of a</span>
<span class="attribution"><span class="source">R. Garrouste</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These giant insects of more than 300 million years ago were formidable hunters in the Paleozoic sky where they were the greatest predators until the end of the Permian, when the first gliding reptiles appeared. This observation complements our vision of the ecosystems of this period during which the conquest of airspace allowed important evolutionary lineages to be established. The great Permian-Triassic crisis (circa 255 million years ago), a major one for all biodiversity, probably also caused the disappearance of these large dragonflies and other giant insects and arthropods that inhabited terrestrial and aquatic ecosystems during the Paleozoic.</p>
<p>This research is published in the journal <a href="https://www.nature.com/articles/s41598-018-30629-w"><em>Nature Scientific Reports</em></a> on August 14, 2018.</p>
<p>To better represent these emblematic fossils, the MNHN’s Paleontology Gallery will present a life-size 3D reconstruction of <em>Meganeura monyi</em>, associated with the unique fossil of this giant dragonfly.</p>
<p>But the question that remains is the possible existence of giant insects nowadays. Large insects still persist, all in the intertropical regions, with beetles more than 18 cm long, butterflies 20 cm wide, and stick insects (shaped like large twigs) 50 cm long. Despite these large sizes, including the body, none has a wingspan or a body size similar to the Paleozoic insects. The largest dragonfly today does not exceed 20 cm wingspan with a filiform body.</p>
<p>Moreover, this gigantism has long overshadowed the existence of smaller Carboniferous insects and perhaps even prevented from seeking them… It is only recently (<a href="https://www.nature.com/articles/nature12629">and by our team</a>) that the highlighting of these small insects, alongside the famous giants, modified the vision perhaps a little simplistic that we had of the ecosystems of this period.</p>
<p>So do not worry: giant insects are no longer among us. But does size matter when we consider the importance of insects in our current ecosystems?</p><img src="https://counter.theconversation.com/content/102384/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Romain Garrouste has received funding from MNHN, CNRS, Sorbonne Universities, LABEX BCDiv, National Geographic, and the Ministry of Foreign Affairs, </span></em></p><p class="fine-print"><em><span>André Nel ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>They hovered in the skies of the Earth 300 million years ago… The giant dragonflies will soon be the stars of the paleontology gallery of France’s Natural History Museum in Paris.Romain Garrouste, Chercheur à l’Institut de systématique, évolution, biodiversité (UMR 7205 MNHN-CNRS-UPMC-EPHE-Univ. Antilles), Muséum national d’histoire naturelle (MNHN)André Nel, Professeur au MNHN, Muséum national d’histoire naturelle (MNHN)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/819632017-08-02T15:44:45Z2017-08-02T15:44:45ZTrying to keep nature the same is a fool’s errand – we should embrace change<figure><img src="https://images.theconversation.com/files/180765/original/file-20170802-14599-1ez2tqj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Scottish beeches – the slowest invasion in history?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/29609591@N08/6197917500/in/photolist-arFWWy-TmZqUm-WSP2rB-pSwE8t-bnCCCP-jbvrQk-aWAG2H-jrSsZU-hnPEVb-jfZZvV-b4VfUa-Usr51g-Vi1129-UfBwBA-WmdCe3-95TtaL-TVjodL-qRUSdT-7y4w3b-5ARQA3-5PeC3W-UQGFR4-98qvtZ-h2xr2T-jDCKXM-itoV2n-7F8Fig-8Z5HJF-8MfePZ-S7qrFP-6UWMqy-Uu82Ai-U8VpBA-riaskM-VC1teo-V1dVdb-UQYmdw-U1R875-7eHNub-QZfzbD-jSeoPR-aDRJyw-gZAizA-gZUC53-5VMCdA-h7Eqps-aC8sHG-dsc8wz-rp5ZEV-oLzzmN">Angus Clyne</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>When it comes to deciding which plants and animals to protect and which to remove, our approach might make even the most forthright nationalist blush if it were ever applied to people. The central question in the UK and many other countries is whether a particular species is <a href="http://www.nonnativespecies.org/index.cfm?pageid=64">native or non-native</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=806&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=806&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=806&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1012&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1012&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180742/original/file-20170802-13549-1sdd42s.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1012&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 warbler.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/yeliseev/4557461548/in/photolist-qE7YQB-7WJbxf-7WJbxd-7WJbxb-7NnZsn-9WcWMK-9WfMuW-7NrYBy-9WfMrS-7NrYrG-9WcWL2-u8Dooh-unUNaN-a1V9Ex-sprWLH-bDSkSd-MiR1ns-a1Y2ay-a1Y25S-a1Y28b-sppYbg-fHNeFJ-9FyEmh-a1V9UZ-goVf6G-mjwPX9-mjvwee-djTXsa-Mfjt37-KV9ky5-ttorpP-u8DnYu-bSM438">Sergey Yeliseev</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Rarer natives are more likely to have government money spent on their protection. The UK has a <a href="http://jncc.defra.gov.uk/page-3408">long list</a> of them, including the likes of the spiny cockle, the moustached warbler and the sturgeon. <a href="http://www.nonnativespecies.org/factsheet/index.cfm">Non-natives</a>, on the other hand, may be rightly targeted for extermination if they threaten significant damage and are spreading fast – <a href="http://www.nonnativespecies.org/factsheet/factsheet.cfm?speciesId=1495">Japanese knotweed</a> and <a href="http://www.nonnativespecies.org/index.cfm?pageid=225">rhododendrons</a> being well known “<a href="https://www.cbd.int/invasive/WhatareIAS.shtml">invasive</a>” examples. </p>
<p>On the <a href="http://ukeconet.org/wp-content/uploads/2009/10/Ian-D.-Rotherham-2005-Invasive-plants-in-woods-forests-and-other-wild-places-some-issues-of-ecology-history-and-perception.-FWAG-Scotland.-June-2005.-12-17.pdf">face of it</a>, native is good and non-native is bad. Not only do we make this distinction at UK level, we do it for species in Scotland, England, Wales and Northern Ireland. It may seem simple, but the very definition is less clear cut than it first appears. </p>
<h2>Unidentified alien beeches</h2>
<p>Take the beech tree. This tree has long been considered <a href="http://www.gov.scot/Publications/2002/06/14891/5529">non-native</a> to Scotland and, in <a href="https://www.pressreader.com/uk/sunday-herald/20160529/282402693632139">some cases</a>, has been treated as an invader. It has been the subject of many back and forth arguments about whether it should be encouraged or removed. </p>
<p>Beeches colonised the south of England after the last Ice Age. They began spreading north but failed initially to establish themselves. This was due to competition with other trees and the subsequent rampant deforestation of the UK by our ancestors. </p>
<p>Nowadays, beeches are found throughout the UK, but considered non-native to Scotland for two reasons. The first relates to the <a href="http://www.snh.org.uk/publications/on-line/advisorynotes/112/112.htm">arbitrary cut-off point</a> that decides these things in the UK: about 7,000 years ago, the time of the post-Ice Age expansion of human agriculture. (Other countries take a different view of time for native/non-native purposes – the US <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/ct/technical/ecoscience/invasive/?cid=nrcs142p2_011124">dates it</a> to 1492, the time of European settlement, for example.) </p>
<p>The second indicator is that beeches are considered to have been introduced to Scotland by people rather than spreading of their own accord. In reality, it has been easier to say this than to prove it. The <a href="https://www.brc.ac.uk/plantatlas/plant/fagus-sylvatica">most recent update</a> to species maps for the UK mapped beeches as native “regardless of status” because it was so hard to figure out which had been introduced by people and which had made it themselves. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=639&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=639&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=639&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=803&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=803&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180739/original/file-20170802-20062-asqmhu.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=803&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Make like a tree.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/beech-tree-643005892?src=_rNZ8kue4z3U99FdpoTb6w-1-64">Pelle Zoltan</a></span>
</figcaption>
</figure>
<p>I recently co-published <a href="http://onlinelibrary.wiley.com/doi/10.1111/jbi.13053/full">a paper</a> which removed this uncertainty. By combining DNA evidence with historic information, we were able to identify the origin of populations of beech in Scotland and in northern England. </p>
<p>It is well known that beech grows and reproduces without problems in the Scottish lowlands. So while humans might have speeded its spread, beeches would have taken root in Scotland anyway. This led us to the conclusion that there is no justifiable reason to maintain its status as non-native, and we should just embrace it as another natural occupant of the Scottish landscape. </p>
<h2>Dragonflies and bumblebees</h2>
<p>This beech controversy is strongly linked to our tendency to be resistant to change in the natural world. We think in terms of communities of plants, animals, fungi and bacteria that live together in the same place at the same time, and tend to view these as fixed and unchanging – something we can describe, quantify and map. </p>
<p>In truth, such communities change constantly as species move in accordance with changes in their environment – little different to how humans shift in response to things like war or economic hardship. With plants and animals, we pick a point in time 7,000 years ago and say the community that existed at that time is native and the species stops here. </p>
<p>The tree bumblebee is another interesting example. It is <a href="http://www.bwars.com/content/bombus-hypnorum-mapping-project">believed to have</a> arrived from the continent under its own steam in about 2001 and spread rapidly up the country. Like beech, its spread was made easier by humans – in this case by providing bird boxes and roof spaces that these bees <a href="https://www.buglife.org.uk/bugs-and-habitats/tree-bumblebee">are adept</a> at colonising. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180733/original/file-20170802-21522-1jd0xzr.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">Bee here now.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tree-bumblebees-bombus-hypnorum-using-old-642490990?src=MNZFyX4XyBXn5fyi5I60fg-1-2">Howard Marsh</a></span>
</figcaption>
</figure>
<p>The tree bumblebee is a clear-cut non-native according to our established definitions. Yet its colonisation of the UK is believed to have been a natural event that would have occurred (more slowly) without human intervention. </p>
<p>It’s also part of a much bigger trend. A wide variety of species including <a href="https://www.bto.org/science/latest-research/species%E2%80%99-ranges-are-shifting-which-direction">birds</a>, <a href="http://butterfly-conservation.org/48-4912/climate-change-sees-butterflies-move-north.html">butterflies</a> and other insects are on the move as our climate warms. Since 1995, some 11 species of dragonflies <a href="https://british-dragonflies.org.uk/node/7137">have returned</a> to or newly arrived in the UK – one in five of all dragonfly species in the country. </p>
<p>We are likely to see many more of these developments as the climate keeps warming, sometimes with <a href="http://science.sciencemag.org/content/355/6332/eaai9214">serious negative effects</a>. It all challenges one of the fundamental principles of conservation, that of keeping things the same. How, then, do we overcome our resistance to change without abandoning efforts to stop the spread of invasive species altogether? </p>
<p>Certainly where an area is of particular biological, historical or cultural significance, we might continue to spend money trying to keep it that way. But more broadly, it makes sense to think in terms of harm and benefits. </p>
<p>With beech, we might say that while its expansion across Scotland is <a href="https://www.plantlife.org.uk/application/files/9914/8233/6415/24216_PL_Bryophites.pdf">undoubtedly a threat</a> to some woodlands, it represents a great opportunity when species like ash and oak are at <a href="http://www.woodlandtrust.org.uk/mediafile/100263370/pg-wt-2014-woodwise-2013-summer.pdf?cb=113e4ffea9f44458b037aa43af664708">significant risk</a> from new pests and diseases. As for the tree bumblebee, rather than damaging ecosystems, it performs vital pollination services while other pollinators <a href="http://www.euractiv.com/section/agriculture-food/news/les-maux-des-abeilles-menacent-lagriculture/">suffer</a> unprecedented declines. </p>
<p>We should continue to use our limited conservation funds to fight invasive species that cause the most damage, while striving to stop human introductions of new species to ever more areas of the globe. But trying to turn back the clock to an arbitrary time in the past is a fool’s errand. Change is the new norm and will be for the foreseeable future. Perhaps the arguments around native and non-native need to stop forever looking back, and start looking forward, too.</p><img src="https://counter.theconversation.com/content/81963/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alistair Jump received funding from the Natural Environment Research Council as part of an ERA-Net BiodivERsA consortium.</span></em></p>Beeches are ‘non-native’ to Scotland because they got there less than 7,000 years ago. No, really.Alistair Jump, Professor of Plant Ecology, University of StirlingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/625192016-07-19T18:37:53Z2016-07-19T18:37:53ZDragonflies as sentinels for freshwater conservation<figure><img src="https://images.theconversation.com/files/131102/original/image-20160719-7877-6zji86.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>Viewed from space, our planet is a blue speck of mostly water in a seemingly endless expanse of darkness. It is this water that is vital for life as we know it. This wonderful life is amazingly complex, yet very fragile. Away from the sea, it is fresh water on which life depends, especially free running water and precious wetlands, all of which are teeming with life. </p>
<p>Yet fresh water is the most threatened habitat on <a href="https://www.theguardian.com/environment/2009/oct/11/freshwater-species-under-threat">Earth</a>. </p>
<p>Several thousand species worldwide live in freshwater habitats, from the smallest ponds to the largest rivers. Some are highly sensitive to any human impact while others are real opportunists. They will inhabit the most artificial of habitats, like cattle troughs and even bird baths. It is this range of sensitivities that make them very useful as measures for the quality of fresh water. </p>
<p>When a water system becomes degraded through human impact like pollution or damming, there is a change in the species profile away from sensitive specialists towards insensitive generalists. We can quantify this and relate it to whether a fresh water system is deteriorating or improving.</p>
<p>A prominent group of species associated with water and that can tell us something about the state of our water resources is dragonflies – the collective term for true dragonflies and damselflies. When they are young they live in the water as larvae, then later emerge as flying adults that grace fresh waters throughout the world, except the ice caps. Both life stages are predatory. </p>
<p>So these beautiful insects are near the top of the food chain and have few natural enemies other than birds. These are occasionally frogs, spiders and robber flies. At times humans enjoy the larvae as a tasty addition to a side dish. For example, in Bali, larvae may be fried in coconut oil and served with vegetables. Indeed, dragonflies and humans are much more intimately linked than normally <a href="https://www.researchgate.net/publication/265306344_Valuing_dragonflies_as_service_providers">thought</a>. </p>
<h2>Tracking dragonflies</h2>
<p>In South Africa, a water-scarce country, we have been conducting <a href="http://www.cons-ent.com/">research</a> on new ways for assessing the quality and ecological health of fresh water systems using dragonflies. There are 162 species of dragonfly in South Africa alone. Some are sensitive specialists, while others are hardy generalists. This and their two-staged lifestyle, with dependencies on both the water and land, make them excellent candidates for freshwater assessment. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=609&fit=crop&dpr=1 600w, https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=609&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=609&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=765&fit=crop&dpr=1 754w, https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=765&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/131097/original/image-20160719-8011-1gig311.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=765&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dragonflies like the white malachite are excellent candidates for water assessment.</span>
<span class="attribution"><span class="source">Michael Samways</span></span>
</figcaption>
</figure>
<p>We have developed an index that is based on three main features of each species in turn. </p>
<ol>
<li><p>The general distribution of a species;</p></li>
<li><p>Its threat status (its rating on the International Union for Conservation of Nature and Natural Resources’ Red List); and</p></li>
<li><p>Its sensitivity to human modifications of the water system.</p></li>
</ol>
<p>When a system deteriorates there is a shift in the total scores of all the species present from high to low. When systems are restored there is a shift in the other direction from low to high. Using dragonflies it is possible to determine whether there should be concern about a system that is going downhill or whether a system is improving, and how well it’s doing. </p>
<p>Using dragonflies to this end is incredibly simple. All you need is a good guide, a pair of close-focus binoculars and a sunny day. </p>
<p>Recently all our research has been synthesised into a <a href="http://biodiversityadvisor.sanbi.org/literature/4327-2/suricata/">user-friendly manual</a> showing how to undertake fresh water assessments. As this index operates at the level of species, it is highly sensitive. And as dragonflies are relatively easy to identify, it is easy to use.</p>
<h2>Next steps</h2>
<p>Dragonflies are pushed away from their normal habitats when invasive alien trees like eucalyptus, wattles and pines shade the water and bank. This can lead them to become locally extinct. This means that the removal of alien trees from the banks of rivers, in particular, is an important nature conservation exercise. It has been one of the great contributions to South Africa’s nature conservation through the governmental <a href="https://www.environment.gov.za/projectsprogrammes/wfw">Working for Water Programme</a>.</p>
<p>But not all human activities are harmful to dragonflies and other water, fauna and flora. Farm dams can encourage many species that would otherwise be very scarce in the area. Good nature conservation dams are those with constant water levels, much water weed and marginal vegetation, and no pollutants, especially fertilisers and pesticides used in agriculture. </p>
<p>Successful management of fresh water biodiversity depends on the quality of data on the species that these ecosystems support. Projects monitoring the health of fresh waters are a vital component of this. The process of fresh water assessment is very pleasant, like going bird watching. This new approach makes freshwater assessment so much easier than in the past and makes a major contribution to nature conservation.</p><img src="https://counter.theconversation.com/content/62519/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Samways receives funding from National Research Foundation and from Mondi. </span></em></p><p class="fine-print"><em><span>John P. Simaika 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>Freshwater is one of the most threatened resources on Earth. Dragonflies can tell us what we need to know about the state of this precious resource.Michael Samways, Professor, Conservation Ecology & Entomology, Stellenbosch UniversityJohn P. Simaika, Department of Conservation Ecology and Entomology, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/602152016-06-01T15:00:39Z2016-06-01T15:00:39ZWhat dragonflies say about our ignorance of the natural world<figure><img src="https://images.theconversation.com/files/124491/original/image-20160530-7700-w1bb54.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This massive dragonfly, the Swordbearer Emperor _Anax gladiator_, is named for the blade-like spike at its tail tip.</span> <span class="attribution"><span class="source">Copyright Jens Kipping</span></span></figcaption></figure><p>Of the 8.7 million species of animals, plants and fungi thought to live on Earth, we have only named <a href="http://www.ncbi.nlm.nih.gov/pubmed/21886479">1.2 million</a>: 86% of the natural world is uncharted. </p>
<p>For most people, both this incredible richness and our ignorance are hard to fathom. Imagine that each of the 6.5 million species thought to live on land – the rest is marine – had an equal share of it. Each species’ plot – also that of the human species – would cover an area only one-quarter the size of Manhattan. Expressed this way, we as humans have not just far overstepped our bounds, but mapped only the equivalent of Europe, India and China, which make up about 14% of global land surface. </p>
<p>What’s worse, the habits and status of only 80,000 species are known well enough to really assess our impact on them. Of those, <a href="http://www.iucnredlist.org/">29% risk extinction</a>. So, returning to the metaphor, the species that we’re actually familiar with equal only the combined area of Spain, France and Turkey. And if 29% of all species died out, that would equate to the entire New World voided of life. </p>
<p>In other words: while we’ve had an apocalyptic impact on the biosphere already, it has been charted as well today as the globe was in Columbus’s day. This matters because knowing other species can provide a moral counterweight to life’s runaway exploitation: intact biodiversity is the undeniable proof that humans can inhabit Earth without destroying it. </p>
<p>That’s why naming species is important. Names harness the power of recognition. They acknowledge the other exists. They introduce familiarity. As someone once exclaimed to me, “you don’t notice species until you know they can have a name!” </p>
<p>In an era of extinction, there are no greater priorities than to <a href="https://www.youtube.com/watch?v=Arr2k7dwzSU">uncover our millions of cohabitants</a> and to <a href="http://jrsbiodiversity.org/grant/stellenbosch_dragonflies/">share our knowledge</a> of these species. This can be done through research, <a href="https://freshwaterblog.net/2015/06/01/discovering-the-dragonflies-and-damselflies-of-eastern-africa/">books</a>, websites, Red Lists of threatened species, <a href="https://www.facebook.com/africanfreshwater">field courses</a>, teaching materials and other media. But while every human relies on this knowledge, even if only by reaping the benefits of agriculture and medicine, few see its advance as their primary responsibility.</p>
<p>Few animals can raise that moral awareness of biodiversity better than dragonflies, literally rising from healthy freshwaters in colour and splendour.</p>
<h2>Breaking the anonymity trap</h2>
<p>Most of what is unknown is not just unseen, but not even being looked for.</p>
<p>There are 6,000 named dragonfly and damselfly species worldwide. These charismatic aquatic insects are regarded as well-known. But last December we published <a href="https://science.naturalis.nl/media/medialibrary/2015/12/60NewDragonflies_fullsize2.pdf">60 new species</a> in one article. This added one species to every 12 known ones in Africa. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/124481/original/image-20160530-7722-39d5bo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124481/original/image-20160530-7722-39d5bo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124481/original/image-20160530-7722-39d5bo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124481/original/image-20160530-7722-39d5bo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124481/original/image-20160530-7722-39d5bo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124481/original/image-20160530-7722-39d5bo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124481/original/image-20160530-7722-39d5bo.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">Known from only one site near Cape Town, the endangered damselfly <em>Spesbona angusta</em> needs all the ‘Good Hope’ (<em>Spes Bona</em> in Latin) it can get.</span>
<span class="attribution"><span class="source">Copyright Jens Kipping</span></span>
</figcaption>
</figure>
<p>Of course these species existed already, but were not noticed and documented before. Most unknown species may seem indistinct or concealed, requiring meticulous lab-work to uncover, but the 60 were found in accessible places all over Africa and are often recognisable even from a photo.</p>
<p>This May, English nature broadcaster Sir David Attenborough was given a <a href="https://www.youtube.com/watch?v=FMDnPUXTcdc&feature=youtu.be">new dragonfly species</a> from Madagascar for his 90th birthday. In the <a href="http://www.nature.com/polopoly_fs/1.19870!/menu/main/topColumns/topLeftColumn/pdf/533172a.pdf">scientific journal <em>Nature</em></a> I explain that both the dragonfly and Attenborough’s legacy stand for a selfless and unconditional love of nature.</p>
<p>I am often asked what the “use” of dragonflies is. They are not studied because they are not proxies of human psyche and society like ants and apes. They are not feared and persecuted like mosquitoes and snakes. They do not feed people like fish, nor pollinate crops like bees.</p>
<p>Rather, the beauty and sensitivity of these creatures – and so many others – stand for the state and needs of nature before our own. Like the instant sense of insignificance when counting stars, biodiversity stretches our perspective on life. Each species is a world parallel to our own, evoking a sense of being among equals.</p>
<h2>What’s in a name</h2>
<p>If species embody sustainability and names give them faces, those tags best be memorable. The sparklewing damselfly <em>Umma gumma</em>, named for the rock band Pink Floyd’s album “<a href="http://www.allmusic.com/album/ummagumma-mw0000191310">Ummagumma</a>” (slang for making love), is <a href="http://www.esf.edu/top10/">a special favourite.</a> The longleg dragonflies <em>Notogomphus kimpavita</em> and <em>N. gorilla</em> were named for the patron saint and conservation flagship of their Angolan and Ugandan regions respectively.</p>
<p>But who is out discovering species and introducing them to mankind? Nature is held hostage by humanity’s growing demands and so conservationists barely have time to find out who they really work for. Environmental consultancy is captive to the market. Many biologists have retreated into the lab. Without funds for discovery and disclosure, even natural history museums are giving up.</p>
<p>Only nine of our 60 new dragonflies were found while one of us worked for a university or museum. The other 33 were found while doing consultancy and 18 were found by a teacher. Much of the best biodiversity research and outreach now comes from devoted amateurs and academics working in their free time, showing how close biodiversity is to the human heart.</p>
<p>In a society governed by money, charity is what we do for others for free. But just as we cannot expect volunteers to protect the environment or eradicate poverty alone, we cannot continue life’s elementary and enlightening exploration without support. Nature needs more explorers.</p><img src="https://counter.theconversation.com/content/60215/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Klaas-Douwe B. Dijkstra receives funding from the JRS Biodiversity Foundation, USA.</span></em></p>There are 6,000 named dragonfly species worldwide but recently 60 new species were found showing how much more we can learn.Klaas-Douwe B. Dijkstra, Honorary research associate Naturalis Biodiversity Center and, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/114392012-12-20T19:42:36Z2012-12-20T19:42:36ZEnter the dragonfly: insect shows human-like visual attention<figure><img src="https://images.theconversation.com/files/18979/original/4f8kk9rm-1355975014.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Despite having "simple" brains, dragonflies appear to be capable of more complex tasks than was first thought.</span> <span class="attribution"><span class="source">Henry McLin</span></span></figcaption></figure><p>Being able to focus on an important object or task while surrounded by distractions is a valuable skill.</p>
<p>It’s an ability that’s probably widespread in the animal kingdom, but is best known in large mammals such as predatory carnivores and primates.</p>
<p>When a lion is hunting a pack of zebras she needs to be able to focus on her target when the herd scatters in all directions at the start of the chase. A successful pursuit depends on being able to fixate on just one target and avoid distractions. (And zebras have evolved disruptive colouration to make this process harder than it might otherwise be.)</p>
<p>Some neuroscientists consider this “selective attention” to be too complex for the simple brains of insects such as the dragonfly.</p>
<p>But new research from our Centre for Neuroscience Research at the University of Adelaide suggests otherwise. </p>
<h2>Catch!</h2>
<p>Another familiar example of selective attention is a cricketer deftly catching a ball as it flies through the air at high speed. The cricketer detects the ball’s motion and trajectory and computes a precise intercept path for their outstretched hands.</p>
<p>This is usually done while running or diving, all the while keeping their gaze fixed on the ball while trying to ignore a complex backdrop of coloured hats and banners bobbing up and down.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/18980/original/kqy9hzxb-1355975317.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/18980/original/kqy9hzxb-1355975317.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18980/original/kqy9hzxb-1355975317.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18980/original/kqy9hzxb-1355975317.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18980/original/kqy9hzxb-1355975317.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18980/original/kqy9hzxb-1355975317.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18980/original/kqy9hzxb-1355975317.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"></span>
<span class="attribution"><span class="source">AAP Image/NZPA Wayne Drought</span></span>
</figcaption>
</figure>
<p>That any animal can manage such feats demonstrates that the brain solves a set of highly complex visual problems. If we can understand how it does so, we can build better robots that could do similar tasks reliably.</p>
<p>But precisely how selective attention works in nature has been a hot topic in neuroscience in recent years. Scientific observations, interpretations and even terminology have generated robust debate. </p>
<h2>Pay attention</h2>
<p><a href="http://www.annualreviews.org/doi/pdf/10.1146/annurev.ne.18.030195.001205">One prominent theory</a> is that selective visual attention is a top-down process – the end result of “endogenous” cognitive processing (i.e. an internally generated “thought” process that directs attention towards a goal) that enhances the relative salience of a feature the subject chooses.</p>
<p>This leads to the suppression of the underlying sensory pathways that would otherwise respond to “distractors”.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/18981/original/59dkhjqf-1355976928.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/18981/original/59dkhjqf-1355976928.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=840&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18981/original/59dkhjqf-1355976928.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=840&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18981/original/59dkhjqf-1355976928.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=840&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18981/original/59dkhjqf-1355976928.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1056&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18981/original/59dkhjqf-1355976928.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1056&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18981/original/59dkhjqf-1355976928.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1056&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">c dbf b b.</span>
<span class="attribution"><span class="source">Nedster78</span></span>
</figcaption>
</figure>
<p>Some of <a href="http://www.jneurosci.org/content/30/8/3058.short">the best evidence</a> for this comes from the brain of monkeys – where we might expect it.</p>
<p>Certain monkey brain cells tend to respond in a manner that resembles the response to a single stimulus, even if a second distractor is presented … so long as the monkey is first trained to direct its attention to one of the stimuli.</p>
<h2>Dragonflies</h2>
<p>But our latest research article – published in the journal Current Biology – provides a provocative new insight: the “simple” dragonfly brain also possesses neurons that lock on and selectively attend to one target. </p>
<p>We found this out by inserting a tiny probe into a part of the dragonfly brain that contains a neuron that tracks small moving targets.</p>
<p>We then recorded from these single brain cells while the dragonfly viewed small moving targets on a videogame screen. We compared responses to single moving targets with those when two targets moved at the same time.</p>
<p>Every time we presented the paired stimuli, the neuron fired with a pattern identical to that for one or other of the single targets.</p>
<p>The target selected differed from trial to trial and very rarely it even switched from one to the other halfway through. But at any one time, these neurons are fully locked on to one of the targets and completely ignore the other.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/oh3YccmQwps?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>A model organism?</h2>
<p>The insect brain is relatively simple and very accessible for physiological recordings. There is also an explosion of <a href="http://www.sciencedirect.com/science/article/pii/S0896627311007860">new research</a> arising from genetic manipulation of neural circuits in fruit flies that provides another powerful tool to establish how the insect brain works.</p>
<p>Insect research is also free of many of the ethical issues involved in invasive research on higher mammals, so our discovery provides a promising new model system for studying neural mechanisms involved in visual attention. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/18977/original/j2hxmdkp-1355974788.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/18977/original/j2hxmdkp-1355974788.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/18977/original/j2hxmdkp-1355974788.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/18977/original/j2hxmdkp-1355974788.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/18977/original/j2hxmdkp-1355974788.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/18977/original/j2hxmdkp-1355974788.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/18977/original/j2hxmdkp-1355974788.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">
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<span class="attribution"><span class="source">Tom Soper Photography</span></span>
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<p>But perhaps the most exciting aspect of our work is that this is the first convincing evidence at the single neuron level from any invertebrate animal for a mechanism akin to selective attention in higher mammals.</p>
<p>To find this in a lowly insect – one apparently similar to dragonflies that flew around 300 million years ago (and long before the first mammals or even dinosaurs appeared on earth) - is rather astonishing.</p>
<p>Indeed it challenges the very basis of our understanding of selective attention itself.</p>
<p>Surely this can’t be the result of top-down cognitive processing on a par with that seen in mammals? Or can it?</p>
<p>One need only to spend a few minutes watching dragonflies hunting on a pond to see that they cruise and hover near swarms of small flies and deftly dart up to capture one after another at high speed.</p>
<p>Some 97% of such attacks lead to successful capture – a statistic that even champion cricketers could only dream of.</p><img src="https://counter.theconversation.com/content/11439/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David O'Carroll receives funding from the Australian Research Council and the US Air Force Office of Scientific Research</span></em></p><p class="fine-print"><em><span>Steven Wiederman 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>Being able to focus on an important object or task while surrounded by distractions is a valuable skill. It’s an ability that’s probably widespread in the animal kingdom, but is best known in large mammals…David O'Carroll, Associate Professor, Centre for Neuroscience Research, University of AdelaideSteven Wiederman, Postdoctoral Researcher, Centre for Neuroscience Research, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.