ASN RSS http://amnat.org/ Latest press releases and announcements from the ASN en-us Fri, 21 Jul 2017 05:00:00 GMT 60 “Using traits to assess nontransitivity of interactions among coral species” http://amnat.org/an/newpapers/SepPrecoda.html A&nbsp;longstanding puzzle is how a large number of species can coexist indefinitely when they’re all competing for a single, limited resource. Why doesn’t a single species crowd out all the others? A possible explanation is that as in the rock-paper-scissors game, no one species outcompetes all the rest. This paper presents evidence that, in the highly diverse world of coral reefs, competitions between coral species are generally not hierarchical, although few follow the rock-paper-scissors model exactly. More than a hundred coral species can coexist on a reef, using multiple strategies to compete with each other for sunlight and living space. Kristin Precoda, Andrew Allen, Liesl Grant, and Joshua Madin gathered a list of wins, losses, and ties between pairs of 111 coral species from 16 prior studies in regions including the Caribbean, the Great Barrier Reef, Taiwan, Hawai‘i, and the Red Sea. They linked each species to traits that could influence its competitive abilities. For example, the tentacles of coral species with larger polyps may have a longer “reach,” and corals that grow upward and outward may shade flatter species. They found that several traits helped predict which species was likely to win, especially for less closely related competitors. However, the outcome for any particular species pair was strongly influenced by as yet unexplained factors, and the same species in a given pair may not always win. The results suggest that the outcome of competition in these species-rich communities is quite nuanced. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">A</span>&nbsp;longstanding puzzle is how a large number of species can coexist indefinitely when they’re all competing for a single, limited resource. Why doesn’t a single species crowd out all the others? A possible explanation is that as in the rock-paper-scissors game, no one species outcompetes all the rest. This paper presents evidence that, in the highly diverse world of coral reefs, competitions between coral species are generally not hierarchical, although few follow the rock-paper-scissors model exactly. </p><p>More than a hundred coral species can coexist on a reef, using multiple strategies to compete with each other for sunlight and living space. Kristin Precoda, Andrew Allen, Liesl Grant, and Joshua Madin gathered a list of wins, losses, and ties between pairs of 111 coral species from 16 prior studies in regions including the Caribbean, the Great Barrier Reef, Taiwan, Hawai‘i, and the Red Sea. They linked each species to traits that could influence its competitive abilities. For example, the tentacles of coral species with larger polyps may have a longer “reach,” and corals that grow upward and outward may shade flatter species. They found that several traits helped predict which species was likely to win, especially for less closely related competitors. However, the outcome for any particular species pair was strongly influenced by as yet unexplained factors, and the same species in a given pair may not always win. The results suggest that the outcome of competition in these species-rich communities is quite nuanced. <a href="http://dx.doi.org/10.1086/692758">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Thu, 13 Jul 2017 05:00:00 GMT “Modeling adaptive and non-adaptive responses of populations to environmental change” http://amnat.org/an/newpapers/SepCoulson.html New theory is presented to predict how populations will respond to environmental change via adaptation and plasticity When the environment changes, populations of wild animals and plants can be affected in a number of ways. In the worst case, they are driven to extinction, while at the other extreme, the change in the environment may have no effect on them at all. A third option is that individuals change in ways that allows them to cope with the new environment. Such change can occur via evolution – a change in the genetic structure of the population – or via something called plasticity, where individuals are able to rapidly alter their phenotypes without any underlying genetic change. Biologists have long been interested in how evolution and plasticity contribute to the ways that populations react to environmental change, but this has been a difficult question to address because of a lack of theory that links plastic and evolutionary change in response to an altered environment. In the paper by Tim Coulson of Oxford University and colleagues in Denmark, France, Switzerland, and the United States, new theory is developed that allows biologists to examine how plasticity and evolution can help populations respond to environmental change. They show that plasticity provides a much faster way of responding to such change than evolution. Evolutionary responses do occur, but they will typically take a few tens of generation. Over this longer time period, plasticity and natural selection (the underpinning of adaptive evolution) can interact to alter the course of evolution. Coulson et al.’s theory offers significant potential to not only understand how populations respond to environmental change, but it also brings together two very disparate bits of existing theory from ecology and evolution: demography and quantitative genetics. Further application of this theory should help explain the intricate interactions between natural selection and plasticity on evolutionary change, providing better insights into the consequences of environmental change on the natural world. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>New theory is presented to predict how populations will respond to environmental change via adaptation and plasticity </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">W</span>hen the environment changes, populations of wild animals and plants can be affected in a number of ways. In the worst case, they are driven to extinction, while at the other extreme, the change in the environment may have no effect on them at all. A third option is that individuals change in ways that allows them to cope with the new environment. Such change can occur via evolution – a change in the genetic structure of the population – or via something called plasticity, where individuals are able to rapidly alter their phenotypes without any underlying genetic change. Biologists have long been interested in how evolution and plasticity contribute to the ways that populations react to environmental change, but this has been a difficult question to address because of a lack of theory that links plastic and evolutionary change in response to an altered environment. In the paper by Tim Coulson of Oxford University and colleagues in Denmark, France, Switzerland, and the United States, new theory is developed that allows biologists to examine how plasticity and evolution can help populations respond to environmental change. They show that plasticity provides a much faster way of responding to such change than evolution. Evolutionary responses do occur, but they will typically take a few tens of generation. Over this longer time period, plasticity and natural selection (the underpinning of adaptive evolution) can interact to alter the course of evolution. Coulson et al.’s theory offers significant potential to not only understand how populations respond to environmental change, but it also brings together two very disparate bits of existing theory from ecology and evolution: demography and quantitative genetics. Further application of this theory should help explain the intricate interactions between natural selection and plasticity on evolutionary change, providing better insights into the consequences of environmental change on the natural world. <a href="http://dx.doi.org/10.1086/692542">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 07 Jul 2017 05:00:00 GMT “Convergently evolved toxic secondary metabolites in plants drive the parallel molecular evolution of insect resistance” http://amnat.org/an/newpapers/VPPetschenka-A.html Plants have to defend themselves against a plethora of herbivorous insects. Over evolutionary times, reciprocal interactions between plants and insects resulted in convergence on all levels, reaching from toxic compounds on the plants’ side and behavioral countermeasures on the herbivores’, down to the molecular level causing specific mechanisms of resistance. Based on a molecular phylogeny of leaf mining flies (family Agromyzidae), the authors report five independent colonization events of cardiac glycoside containing host plants from four botanical families. These toxins owe their name to the therapeutic effect they exert – at very low concentration – in human patients with heart conditions. However, at the concentrations present in the host plants, cardiac glycosides block a ubiquitous animal ion carrier, the sodium pump or Na,K-ATPase. In all of the fly species that are specialized on cardiac glycoside–containing plants, the authors detected amino acid substitutions in the sodium pump that may render the enzyme less sensitive to the detrimental effect of the toxins. This five-fold convergent evolution of toxin resistance adds to the authors’ previous evidence that target site insensitivity of the sodium pump is a common response to the challenge presented by dietary cardiac glycosides and leads to highly predictable evolution at the level of amino acids. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><span style="line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-size: 40px; font-weight: bold; float: left;">P</span>lants have to defend themselves against a plethora of herbivorous insects. Over evolutionary times, reciprocal interactions between plants and insects resulted in convergence on all levels, reaching from toxic compounds on the plants&rsquo; side and behavioral countermeasures on the herbivores&rsquo;, down to the molecular level causing specific mechanisms of resistance. Based on a molecular phylogeny of leaf mining flies (family Agromyzidae), the authors report five independent colonization events of cardiac glycoside containing host plants from four botanical families. These toxins owe their name to the therapeutic effect they exert &ndash; at very low concentration &ndash; in human patients with heart conditions. However, at the concentrations present in the host plants, cardiac glycosides block a ubiquitous animal ion carrier, the sodium pump or Na,K-ATPase. In all of the fly species that are specialized on cardiac glycoside&ndash;containing plants, the authors detected amino acid substitutions in the sodium pump that may render the enzyme less sensitive to the detrimental effect of the toxins. This five-fold convergent evolution of toxin resistance adds to the authors&rsquo; previous evidence that target site insensitivity of the sodium pump is a common response to the challenge presented by dietary cardiac glycosides and leads to highly predictable evolution at the level of amino acids. <a href="http://dx.doi.org/10.1086/691711">Read&nbsp;the&nbsp;Article</a></p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"><span style="font-family: Georgia; font-size: large;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 07 Jul 2017 05:00:00 GMT “Bees without flowers: Before peak bloom, diverse native bees find insect-produced honeydew sugars” http://amnat.org/an/newpapers/AugMeiners.html What do bees do when they don't have flowers? Forty-two species of wild bees can find insect honeydew sugars on a stick! What do bees do when flowers are few? They find invisible honeydew. While studying bee biodiversity at California’s Pinnacles National Park, researchers from the University of Florida and the USDA at Utah State University discovered native, solitary bees foraging on sugars from insect-produced “honeydew” during the low-bloom early spring. Honeydew sugars, which are excreted by plant-feeding insects like aphids and scales, are similar in content and concentration to floral nectar but have no inherent scent or visual signal. Mutualistic relationships between honeydew producers and ants are well known. Use of honeydew across a native bee community, however, had never been evaluated despite its potential as an emergency food to tide over bees facing degraded habitats or delayed bloom. Bees foraging on honeydew is particularly interesting given that decades of research have focused on bee responses to the colors, scents, shapes, humidity, temperature, and even the electric fields of flowers, and their influence on floral evolution. How solitary bees find scentless, invisible sugars on flowerless plants, however, is a mystery. Meiners and colleagues set up a field experiment to determine how many bee species use honeydew and how they find it on non-flowering shrubs. They used artificial honeydew, color signals, infrared thermometers, and scale insecticide to determine that forty-two species of mostly solitary bees can quickly find unadvertised sugars without relying on cues from the scale insects or host plants. To explain this ability, the team analyzed the visitation response curve and hypothesized that foraging strategies for native bees may include “interspecific eavesdropping,” or noticing the activity of other bee species that have stumbled upon a novel resource. This is important because, while honeybees communicate about resources via the waggle dance, solitary bees were assumed to forage independently and to focus on floral cues. Results of this study suggest that native bee foraging may be more opportunistic, dynamic, and interconnected across a diverse community than was previously understood. At a perilous time for bee populations, the use of nontraditional resources and interspecific cues may influence how diverse native bees cope with floral unpredictability and increasing environmental change. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>What do bees do when they don't have flowers? Forty-two species of wild bees can find insect honeydew sugars on a stick! </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">W</span>hat do bees do when flowers are few? They find invisible honeydew. While studying bee biodiversity at California’s Pinnacles National Park, researchers from the University of Florida and the USDA at Utah State University discovered native, solitary bees foraging on sugars from insect-produced “honeydew” during the low-bloom early spring. Honeydew sugars, which are excreted by plant-feeding insects like aphids and scales, are similar in content and concentration to floral nectar but have no inherent scent or visual signal. Mutualistic relationships between honeydew producers and ants are well known. Use of honeydew across a native bee community, however, had never been evaluated despite its potential as an emergency food to tide over bees facing degraded habitats or delayed bloom. </p><p>Bees foraging on honeydew is particularly interesting given that decades of research have focused on bee responses to the colors, scents, shapes, humidity, temperature, and even the electric fields of flowers, and their influence on floral evolution. How solitary bees find scentless, invisible sugars on flowerless plants, however, is a mystery. </p> <p>Meiners and colleagues set up a field experiment to determine how many bee species use honeydew and how they find it on non-flowering shrubs. They used artificial honeydew, color signals, infrared thermometers, and scale insecticide to determine that forty-two species of mostly solitary bees can quickly find unadvertised sugars without relying on cues from the scale insects or host plants. To explain this ability, the team analyzed the visitation response curve and hypothesized that foraging strategies for native bees may include “interspecific eavesdropping,” or noticing the activity of other bee species that have stumbled upon a novel resource. This is important because, while honeybees communicate about resources via the waggle dance, solitary bees were assumed to forage independently and to focus on floral cues. </p><p>Results of this study suggest that native bee foraging may be more opportunistic, dynamic, and interconnected across a diverse community than was previously understood. At a perilous time for bee populations, the use of nontraditional resources and interspecific cues may influence how diverse native bees cope with floral unpredictability and increasing environmental change. <a href="http://dx.doi.org/10.1086/692437">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 07 Jul 2017 05:00:00 GMT “Phylogeny, traits and biodiversity of a Neotropical bat assemblage: Close relatives show similar responses to local deforestation” http://amnat.org/an/newpapers/AugFrank.html Bat relatives show similar response to local deforestation: big bats are the winners Researchers at Stanford University have been studying how bats survive in areas where humans and wildlife collide and coexist for years in order to understand how deforestation impacts the fates of whole groups of organisms. Every year from 2009 to 2013, researchers captured and identified bats in coffee fields, forest fragments, and a forest reserve in southern Costa Rica. By statistically correcting for differences in species’ detectability between forest and agriculture, they found that species responded to deforestation at extremely local scales (~50&nbsp;m), and that evolutionarily close relatives had similar responses to deforestation.Few species traits explained bats’ ability to use human-dominated areas, although bigger bats tended to do better than their smaller relatives, likely because large bats are bad at maneuvering through dense tropical forests. Bats play an important role in ecosystem function by pollinating plants, dispersing seeds and depleting insects, so declines in bat populations could cascade into other systems. This work introduces a new framework for using evolutionary relationships to hone predictions and evaluate the impacts of humans on wildlife in order to aid in species conservation. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>Bat relatives show similar response to local deforestation: big bats are the winners </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">R</span>esearchers at Stanford University have been studying how bats survive in areas where humans and wildlife collide and coexist for years in order to understand how deforestation impacts the fates of whole groups of organisms. Every year from 2009 to 2013, researchers captured and identified bats in coffee fields, forest fragments, and a forest reserve in southern Costa Rica. By statistically correcting for differences in species’ detectability between forest and agriculture, they found that species responded to deforestation at extremely local scales (~50&nbsp;m), and that evolutionarily close relatives had similar responses to deforestation.</p><p>Few species traits explained bats’ ability to use human-dominated areas, although bigger bats tended to do better than their smaller relatives, likely because large bats are bad at maneuvering through dense tropical forests. Bats play an important role in ecosystem function by pollinating plants, dispersing seeds and depleting insects, so declines in bat populations could cascade into other systems. This work introduces a new framework for using evolutionary relationships to hone predictions and evaluate the impacts of humans on wildlife in order to aid in species conservation. <a href="http://dx.doi.org/10.1086/692534">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 07 Jul 2017 05:00:00 GMT Get Involved with the ASN! http://amnat.org/announcements/CallInvolved.html We had a great conference in Portland! &nbsp;It was wonderful to see such innovative research and energetic participation. &nbsp;What a fun community! &nbsp;Look out for the stand-alone meeting in Asilomar, which will celebrate 150 years of the American Society of Naturalists! &nbsp; &nbsp; ASN wants to involve its membership in its activities! &nbsp;Here are some ways you could be involved: &nbsp; Science advocacy: &nbsp; If you think it is a good idea for ASN to establish a committee for science advocacy, let us know! &nbsp;If you yourself would be interested in being involved in that committee, even better. Let us know your ideas and interest by sending an e-mail, with the header “Science Advocacy” to asnpresident@gmail.com. &nbsp; Diversity: If you have ideas for how ASN could promote diversity, and if you are interested in serving on an ASN Diversity Committee, let us know your ideas and interest by sending an e-mail, with the header “Diversity” to asnpresident@gmail.com. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; Regional Meetings and Workshops: ASN supports local regional meetings and special workshops through travel grants, registration discounts, etc. &nbsp;If you are interested in serving on the “Regional Meeting Liaison Committee” or the “Workshop Committee” to facilitate the sponsorship of these events, let us know your ideas and interest by sending an e-mail, with the header “Workshops” to asnpresident@gmail.com. &nbsp; <p>We had a great conference in Portland! &nbsp;It was wonderful to see such innovative research and energetic participation. &nbsp;What a fun community! &nbsp;Look out for the stand-alone meeting in Asilomar, which will celebrate <a href="http://amnat150.org/">150 years of the American Society of Naturalists!</a> &nbsp;<br /> &nbsp;<br /> ASN wants to involve its membership in its activities! &nbsp;Here are some ways you could be involved:<br /> &nbsp;<br /> <strong>Science advocacy: </strong>&nbsp;<br /> If you think it is a good idea for ASN to establish a committee for science advocacy, let us know! &nbsp;If you yourself would be interested in being involved in that committee, even better. Let us know your ideas and interest by sending an e-mail, with the header &ldquo;Science Advocacy&rdquo; to <a href="mailto:asnpresident@gmail.com?subject=Science%20Advocacy">asnpresident@gmail.com</a>.<br /> &nbsp;<br /> <strong>Diversity</strong>:<br /> If you have ideas for how ASN could promote diversity, and if you are interested in serving on an ASN Diversity Committee, let us know your ideas and interest by sending an e-mail, with the header &ldquo;Diversity&rdquo; to <a href="mailto:asnpresident@gmail.com?subject=Diversity">asnpresident@gmail.com.</a><br /> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;<br /> <strong>Regional Meetings and Workshops</strong>:<br /> ASN supports local regional meetings and special workshops through travel grants, registration discounts, etc. &nbsp;If you are interested in serving on the &ldquo;Regional Meeting Liaison Committee&rdquo; or the &ldquo;Workshop Committee&rdquo; to facilitate the sponsorship of these events, let us know your ideas and interest by sending an e-mail, with the header &ldquo;Workshops&rdquo; to <a href="mailto:asnpresident@gmail.com?subject=Workshops">asnpresident@gmail.com.</a></p> <p>&nbsp;</p> Thu, 06 Jul 2017 05:00:00 GMT Frequently Asked Questions about the ASN Meetings http://amnat.org/announcements/FAQMeetings.html Some of you asked for information about why the Asilomar meetings are held when and where they are. &nbsp;Here are some answers: &nbsp; Why is registration capped? Registration is capped for a couple reasons. &nbsp;First, according to surveys, what people like most about these meetings is that they are small; there are concurrent sessions only in the mornings, and everyone eats and socializes together. &nbsp;Second, the venue itself is small; Asilomar can host meetings of two sizes—our current size &nbsp;of 200, or a larger one of 500. &nbsp;We would not be able to fill the larger venue, according to past registration rates, and we would lose a lot of money if we tried and failed. &nbsp; Why hold it in January? We surveyed the membership, and they preferred a January meeting to another summer meeting, by far. &nbsp; Why Asilomar? Why Asilomar again? &nbsp;We hear you! &nbsp;We’d like to be able to change location periodically to allow easier access for members not near Asilomar. &nbsp;We’ve been looking for other venues that fit the following criteria: &nbsp;It will agree to host a small group. &nbsp;It is easily accessible in winter. &nbsp;It is not too expensive, with respect to both conference facilities AND housing options. &nbsp;It is near some natural area. &nbsp;If you know of such a place (not just the idea of such place, but a real place, complete with details), let us know! Send suggestions to Mark McPeekSome of you have asked for information about why the Joint Society meetings for Evolution are held when and where they are. Here are some answers: &nbsp; Who chooses the locations of the Evolution Meetings, and what do they base their decision on? &nbsp; The choice of venue for the joint Evolution Meeting is decided by the executive councils of all three societies, with input from a committee that is tasked with researching potential locations, pricing out costs of conference facilities, conference services, and housing options, and reporting their findings to the council. &nbsp;These people do an enormous amount of work getting proposals from different conference facilities, negotiating with them, and supervising them to pull the whole thing off. &nbsp;That committee and the council consider the following issues when they decide on the venue: &nbsp; Region: The priority is to have the meeting in a region that has not recently had a meeting (e.g. West Coast, Northeast, Southwest, Southeast, Midwest, etc.). We rotate locations so that certain populations do not need to travel more than others. &nbsp; Location: Locations that are reasonably accessible by air or car are favored. So are places that are pleasant to visit and where there are interesting things to do. &nbsp; Venue: The venue needs to be affordable, in a decent location with restaurants and hotels nearby, and near cheaper housing options, such as dorms. &nbsp; &nbsp; Total cost: &nbsp; The total price that you pay to attend the conference includes registration, transportation, and housing. &nbsp;The choice of venue is based on the sum of all those costs. Facility rental and services (and therefore registration) may be cheap in one location, but housing could be very expensive, making it unfeasible. All costs are considered—not just registration costs, when making a decision. &nbsp; Why don’t we have the meetings at universities any more? &nbsp; It used to be that we held meetings at universities, with dorms available, and local organizers. &nbsp;A lot of people liked that. &nbsp;These days, universities do rent out facilities, but they are seldom cheaper, and often more expensive, than conference facilities. &nbsp;They are also much more unpredictable and frequently cancel dorm availability or other building use if they need it for themselves. &nbsp;It is very difficult, and sometimes not possible, to get them to commit to providing facilities that we need as far ahead of time as we need them to. &nbsp;Because our meetings have grown in size, universities frequently do not have adequate facilities to accommodate all the concurrent sessions, plenaries, and display space that we need. &nbsp;Finally, it has also become nearly impossible to find willing altruistic and masochistic organizers for our meetings, since the meeting has grown in size and complexity. &nbsp;Conference facilities work with conference organizers, and we have more functional, predictable, and affordable conferences as a result of working with them. <p>Some of you asked for information about why the Asilomar meetings are held when and where they are. &nbsp;Here are some answers:<br /> &nbsp;<br /> <strong>Why is registration capped?</strong><br /> Registration is capped for a couple reasons. &nbsp;First, according to surveys, what people like most about these meetings is that they are small; there are concurrent sessions only in the mornings, and everyone eats and socializes together. &nbsp;Second, the venue itself is small; Asilomar can host meetings of two sizes&mdash;our current size &nbsp;of 200, or a larger one of 500. &nbsp;We would not be able to fill the larger venue, according to past registration rates, and we would lose a lot of money if we tried and failed.<br /> &nbsp;<br /> <strong>Why hold it in January?</strong><br /> We surveyed the membership, and they preferred a January meeting to another summer meeting, by far.<br /> &nbsp;<br /> <strong>Why Asilomar?</strong><br /> Why Asilomar again? &nbsp;We hear you! &nbsp;We&rsquo;d like to be able to change location periodically to allow easier access for members not near Asilomar. &nbsp;We&rsquo;ve been looking for other venues that fit the following criteria: &nbsp;It will agree to host a small group. &nbsp;It is easily accessible in winter. &nbsp;It is not too expensive, with respect to both conference facilities AND housing options. &nbsp;It is near some natural area. &nbsp;If you know of such a place (not just the idea of such place, but a real place, complete with details), let us know! <a href="mailto:mark.mcpeek@dartmouth.edu">Send suggestions to Mark McPeek</a></p><p>Some of you have asked for information about why the Joint Society meetings for Evolution are held when and where they are. Here are some answers:<br /> &nbsp;<br /> <strong>Who chooses the locations of the Evolution Meetings, and what do they base their decision on? &nbsp;</strong><br /> The choice of venue for the joint Evolution Meeting is decided by the executive councils of all three societies, with input from a committee that is tasked with researching potential locations, pricing out costs of conference facilities, conference services, and housing options, and reporting their findings to the council. &nbsp;These people do an enormous amount of work getting proposals from different conference facilities, negotiating with them, and supervising them to pull the whole thing off. &nbsp;That committee and the council consider the following issues when they decide on the venue:<br /> &nbsp;<br /> <strong>Region</strong>:<br /> The priority is to have the meeting in a region that has not recently had a meeting (e.g. West Coast, Northeast, Southwest, Southeast, Midwest, etc.). We rotate locations so that certain populations do not need to travel more than others.<br /> &nbsp;<br /> <strong>Location:</strong><br /> Locations that are reasonably accessible by air or car are favored. So are places that are pleasant to visit and where there are interesting things to do.<br /> &nbsp;<br /> <strong>Venue: </strong><br /> The venue needs to be affordable, in a decent location with restaurants and hotels nearby, and near cheaper housing options, such as dorms. &nbsp;<br /> &nbsp;<br /> <strong>Total cost:</strong> &nbsp;<br /> The total price that you pay to attend the conference includes registration, transportation, and housing. &nbsp;The choice of venue is based on the sum of all those costs. Facility rental and services (and therefore registration) may be cheap in one location, but housing could be very expensive, making it unfeasible. All costs are considered&mdash;not just registration costs, when making a decision.<br /> &nbsp;<br /> <strong>Why don&rsquo;t we have the meetings at universities any more?</strong> &nbsp;<br /> It used to be that we held meetings at universities, with dorms available, and local organizers. &nbsp;A lot of people liked that. &nbsp;These days, universities do rent out facilities, but they are seldom cheaper, and often more expensive, than conference facilities. &nbsp;They are also much more unpredictable and frequently cancel dorm availability or other building use if they need it for themselves. &nbsp;It is very difficult, and sometimes not possible, to get them to commit to providing facilities that we need as far ahead of time as we need them to. &nbsp;Because our meetings have grown in size, universities frequently do not have adequate facilities to accommodate all the concurrent sessions, plenaries, and display space that we need. &nbsp;Finally, it has also become nearly impossible to find willing altruistic and masochistic organizers for our meetings, since the meeting has grown in size and complexity. &nbsp;Conference facilities work with conference organizers, and we have more functional, predictable, and affordable conferences as a result of working with them.</p> Thu, 06 Jul 2017 05:00:00 GMT “Evolutionary scenarios and primate natural history” http://amnat.org/an/newpapers/VPGreene-A.html Abstract Scenarios summarize evolutionary patterns and processes, by interpreting organismal traits and their natural history correlates in a phylogenetic context. They are constructed by: (1) describing phenotypes (including physiology and behavior), ideally with attention to formative roles of development, experience, and culture; (2) inferring homologies, homoplasies, ancestral character states, and their transformations with phylogenetic analyses; and (3) integrating those components with ecological and other ancillary data. At their best, evolutionary scenarios are factually dense narratives that entail no known falsehoods; their empirical and methodological shortcomings are transparent, they might be rejected based on new discoveries, and their potential ideological pitfalls are flagged for scrutiny. They are exemplified here by homoplastic foraging with percussive tools by humans, chimpanzees, capuchins, and macaques; homoplastic hunting with spears by humans and chimpanzees; and private experiences (e.g., sense of fairness, grief) among diverse animals, the homologous or homoplastic status of which often remains unexplored. Although scenarios are problematic when used to bolster political agendas, if constructed carefully and regarded skeptically, they can synthesize knowledge, inspire research, engender public understanding of evolution, enrich ethical debates, and provide a deeper historical context for conservation, including nature appreciation. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">S</span>cenarios summarize evolutionary patterns and processes, by interpreting organismal traits and their natural history correlates in a phylogenetic context. They are constructed by: (1) describing phenotypes (including physiology and behavior), ideally with attention to formative roles of development, experience, and culture; (2) inferring homologies, homoplasies, ancestral character states, and their transformations with phylogenetic analyses; and (3) integrating those components with ecological and other ancillary data. At their best, evolutionary scenarios are factually dense narratives that entail no known falsehoods; their empirical and methodological shortcomings are transparent, they might be rejected based on new discoveries, and their potential ideological pitfalls are flagged for scrutiny. They are exemplified here by homoplastic foraging with percussive tools by humans, chimpanzees, capuchins, and macaques; homoplastic hunting with spears by humans and chimpanzees; and private experiences (e.g., sense of fairness, grief) among diverse animals, the homologous or homoplastic status of which often remains unexplored. Although scenarios are problematic when used to bolster political agendas, if constructed carefully and regarded skeptically, they can synthesize knowledge, inspire research, engender public understanding of evolution, enrich ethical debates, and provide a deeper historical context for conservation, including nature appreciation. <a href="http://dx.doi.org/10.1086/692830">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Tue, 27 Jun 2017 05:00:00 GMT “An ecological perspective on sleep disruption” http://amnat.org/an/newpapers/SepTougeron.html Advances in the ecology of sleep in insects: linking laboratory and field studies to identify sleep-disruptive factors Many animals, including insects, spend large proportions of their time apparently doing nothing (i.e., in an inactive state), but the general importance of these periods of inactivity have received very little attention from ecologists. However recent neurobehavioral research, mostly in the laboratory, has demonstrated that most of these inactive periods in insects share the key characteristics of sleep. Furthermore, disrupting this sleep-like state results a sleep “rebound” (more daytime sleep the following day) and performance deficits ranging from impaired learning to reduced longevity. In a new article in The&nbsp;American Naturalist, Kévin Tougeron and Paul Abram, two researchers from France and Canada, synthesize existing laboratory data on insect sleep research and extrapolate this evidence to the ecology of insects in natural settings, arguing that is a vital but overlooked aspect of their ecology. First, factors likely to disrupt insect sleep are identified, including several aspects of ongoing global change such as warming nights, artificial light at night, and noise and vibrations from human activity. Second, the article discusses potential consequences of sleep disruption for individuals, populations, and communities of insects; these include ecosystem services provided by beneficial insects such as biological control agents and pollinators. The authors hope that this article will help to guide future research in an emerging area, the ecology of sleep. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>Advances in the ecology of sleep in insects: linking laboratory and field studies to identify sleep-disruptive factors </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">M</span>any animals, including insects, spend large proportions of their time apparently doing nothing (i.e., in an inactive state), but the general importance of these periods of inactivity have received very little attention from ecologists. However recent neurobehavioral research, mostly in the laboratory, has demonstrated that most of these inactive periods in insects share the key characteristics of sleep. Furthermore, disrupting this sleep-like state results a sleep “rebound” (more daytime sleep the following day) and performance deficits ranging from impaired learning to reduced longevity. </p><p>In a new article in <i>The&nbsp;American Naturalist</i>, Kévin Tougeron and Paul Abram, two researchers from France and Canada, synthesize existing laboratory data on insect sleep research and extrapolate this evidence to the ecology of insects in natural settings, arguing that is a vital but overlooked aspect of their ecology. First, factors likely to disrupt insect sleep are identified, including several aspects of ongoing global change such as warming nights, artificial light at night, and noise and vibrations from human activity. Second, the article discusses potential consequences of sleep disruption for individuals, populations, and communities of insects; these include ecosystem services provided by beneficial insects such as biological control agents and pollinators. The authors hope that this article will help to guide future research in an emerging area, the ecology of sleep. <a href="http://dx.doi.org/10.1086/692604">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Tue, 27 Jun 2017 05:00:00 GMT “Quantitative genetic variation in, and environmental effects on, pathogen resistance and temperature-dependent disease severity in a wild trout” http://amnat.org/an/newpapers/AugDebes.html Disease severity may differ among individuals because of the pathogen amount that an individual carries and the health damage that a specific pathogen amount can cause. Disease-severity differences may underlie genetic and environmental variation. Importantly, only genetic variation can enable evolution by natural selection towards more pathogen-resistant or disease-tolerant populations. However, the magnitude and evolutionary importance of the genetic variation may change with the environment. A study appearing in The&nbsp;American Naturalist shows how strongly genetic and environmental variation for pathogen infection and the severity of pathogen-induced disease can differ between two natural populations and informs us about possible evolution in the presence of a disease. In salmonid fishes, such as trout, a microscopic parasite induces the potentially fatal proliferative kidney disease (PKD), whose severity increases with water temperatures. By electrofishing trout siblings in two neighboring Estonian rivers with different water temperatures and using a combined morphological and molecular approach, Paul Debes, Riho Gross, and Anti Vasem&auml;gi are able to disentangle and quantify the genetic and environmental variation for parasite amount carried (resistance-1) and PKD severity. Nonetheless, the researchers find that genetic variance for parasite resistance is much higher in the colder river, whereas the disease manifests more severely with a somewhat larger genetic variance in the warmer river. This suggests that selection for parasite resistance proceeds more rapidly under warmer water temperatures, when a stronger selection by a more severe PKD is expected, and which may deplete the genetic resistance variance. However, because water temperature varies spatially and temporally, natural selection and thus the intensity of evolutionary change may also vary spatially and temporally. Thus, the study highlights how environmental variation governs disease severity, affects genetic variance for resistance and disease traits, and may hamper evolution towards more resistant or tolerant populations. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">D</span>isease severity may differ among individuals because of the pathogen amount that an individual carries and the health damage that a specific pathogen amount can cause. Disease-severity differences may underlie genetic and environmental variation. Importantly, only genetic variation can enable evolution by natural selection towards more pathogen-resistant or disease-tolerant populations. However, the magnitude and evolutionary importance of the genetic variation may change with the environment. A study appearing in <i>The&nbsp;American Naturalist</i> shows how strongly genetic and environmental variation for pathogen infection and the severity of pathogen-induced disease can differ between two natural populations and informs us about possible evolution in the presence of a disease.</p> <p>In salmonid fishes, such as trout, a microscopic parasite induces the potentially fatal proliferative kidney disease (PKD), whose severity increases with water temperatures. By electrofishing trout siblings in two neighboring Estonian rivers with different water temperatures and using a combined morphological and molecular approach, Paul Debes, Riho Gross, and Anti Vasem&auml;gi are able to disentangle and quantify the genetic and environmental variation for parasite amount carried (resistance-1) and PKD severity. Nonetheless, the researchers find that genetic variance for parasite resistance is much higher in the colder river, whereas the disease manifests more severely with a somewhat larger genetic variance in the warmer river. This suggests that selection for parasite resistance proceeds more rapidly under warmer water temperatures, when a stronger selection by a more severe PKD is expected, and which may deplete the genetic resistance variance. However, because water temperature varies spatially and temporally, natural selection and thus the intensity of evolutionary change may also vary spatially and temporally. Thus, the study highlights how environmental variation governs disease severity, affects genetic variance for resistance and disease traits, and may hamper evolution towards more resistant or tolerant populations. <a href="http://dx.doi.org/10.1086/692536">Read&nbsp;the&nbsp;Article</a></p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"><span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Mon, 26 Jun 2017 05:00:00 GMT “Ants at plant wounds – a little-known trophic interaction with evolutionary implications for ant-plant interactions” http://amnat.org/an/newpapers/SepStaab-A.html Ants visiting plant wounds may have stimulated the evolution of extrafloral nectaries Abstract Extrafloral nectaries (EFNs) allow plants to engage in mutualisms with ants preventing herbivory in exchange for food. EFNs occur scattered through the plant phylogeny and likely evolved independently from herbivore-created wounds subsequently visited by ants collecting leaked sap. Records of wound-feeding ants are, however, anecdotal. By surveying 38,000 trees from 40 species, we conduct the first quantitative ecological study of this overlooked behavior. Ant-wound interactions were widespread (0.5% of tree individuals) and occurred on 23 tree species. Interaction networks were opportunistic, closely resembling ant-EFNs networks. Fagaceae, a family lacking EFNs, were strongly overrepresented. For Fagaceae, ant occurrence at wounds correlated with species-level leaf damage, potentially indicating that wounds may attract mutualistic ants, supporting the hypothesis of ant-tended wounds as precursors of ant-EFNs mutualisms. Given the commonness of herbivore wounds, wound sap as steadily available food source might furthermore help to explain the overwhelming abundance of ants in (sub)tropical forest canopies. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>Ants visiting plant wounds may have stimulated the evolution of extrafloral nectaries </b></p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">E</span>xtrafloral nectaries (EFNs) allow plants to engage in mutualisms with ants preventing herbivory in exchange for food. EFNs occur scattered through the plant phylogeny and likely evolved independently from herbivore-created wounds subsequently visited by ants collecting leaked sap. Records of wound-feeding ants are, however, anecdotal. By surveying 38,000 trees from 40 species, we conduct the first quantitative ecological study of this overlooked behavior. Ant-wound interactions were widespread (0.5% of tree individuals) and occurred on 23 tree species. Interaction networks were opportunistic, closely resembling ant-EFNs networks. Fagaceae, a family lacking EFNs, were strongly overrepresented. For Fagaceae, ant occurrence at wounds correlated with species-level leaf damage, potentially indicating that wounds may attract mutualistic ants, supporting the hypothesis of ant-tended wounds as precursors of ant-EFNs mutualisms. Given the commonness of herbivore wounds, wound sap as steadily available food source might furthermore help to explain the overwhelming abundance of ants in (sub)tropical forest canopies. <a href="http://dx.doi.org/10.1086/692735">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Mon, 26 Jun 2017 05:00:00 GMT “Multispecies coexistence without diffuse competition; or why phylogenetic signal and trait clustering weakens coexistence” http://amnat.org/an/newpapers/AugStump.html How competitive interactions are affected when species have different effects on one another Most species compete with a mix of close competitors and distant competitors. What factors determine the structure of competitive interactions is hotly debated (for example, do related species compete more?). However, what is not clear is whether this structure matters for the community as a whole. Is a community where species have a mix of strong and weak competitors more stable than one where each species competes equally, and are there other emergent effects? Simon Stump, a research associate at Michigan State University’s W.&nbsp;K..&nbsp;Kellogg Biological Station, developed a simple theoretical model to tackle this question. Inspired by work in tropical forests, the model examines how trees can coexist either by using different parts of habitat, or by having different natural enemies. He demonstrates that the structure of competition can have three community-level effects: one that alters how stable a community is overall, and two that alter which species are the dominant competitors. He examines how these three effects play out differently in several different communities. According to this model, the presence of some strong competitors and some weak competitors will alter community dynamics in two ways. First, many species will be equally competitive, because there will often be a trade-off between having many strong competitors in a good niche and having few strong competitors in a poor niche. Second, such communities will be more fragile than expected; the model gives methods for measuring this effect. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>How competitive interactions are affected when species have different effects on one another </b></p><p><span style="line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-size: 40px; font-weight: bold; float: left;">M</span>ost species compete with a mix of close competitors and distant competitors. What factors determine the structure of competitive interactions is hotly debated (for example, do related species compete more?). However, what is not clear is whether this structure matters for the community as a whole. Is a community where species have a mix of strong and weak competitors more stable than one where each species competes equally, and are there other emergent effects?</p> <p>Simon Stump, a research associate at Michigan State University&rsquo;s W.&nbsp;K..&nbsp;Kellogg Biological Station, developed a simple theoretical model to tackle this question. Inspired by work in tropical forests, the model examines how trees can coexist either by using different parts of habitat, or by having different natural enemies. He demonstrates that the structure of competition can have three community-level effects: one that alters how stable a community is overall, and two that alter which species are the dominant competitors. He examines how these three effects play out differently in several different communities.</p> <p>According to this model, the presence of some strong competitors and some weak competitors will alter community dynamics in two ways. First, many species will be equally competitive, because there will often be a trade-off between having many strong competitors in a good niche and having few strong competitors in a poor niche. Second, such communities will be more fragile than expected; the model gives methods for measuring this effect. <a href="http://dx.doi.org/10.1086/692470">Read&nbsp;the&nbsp;Article</a></p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"><span style="font-family: Georgia; font-size: large;"><i>More forthcoming papers</i> &raquo;</span></a></div> Thu, 22 Jun 2017 05:00:00 GMT “A breath of fresh air in the foraging theory: the importance of wind for food size selection in a central place forager” http://amnat.org/an/newpapers/SepAlma.html The load size selected by organisms depends on the costs of transportation, manipulation and discovery, and biotic constraints such as predation and competition. However, studies about the effect of abiotic factors on loading prey selection are few and limited to evaluation of how these factors affect animal movement. In regions characterized by strong and constant wind, leaf-cutting ants spend more time bringing resources to their nests. Wind negatively affects ant movement, decreasing their speed and blowing the ants off foraging trails. Considering this, Andrea Marina Alma and colleagues at the Laboratorio Ecotono has developed a mathematical model unifying theory, individual ant behavior, the effect of wind, and the underground tasks that determine load size. In addition, they have tested whether the model predictions agree with ant behavior, sampling the load size transported by workers in windy regions of Patagonia, Argentina. They found that as wind speed at ground level increased from 0 to 2 km/h, load size decreased from 91 to 30 mm², a prediction that agreed with empirical data from windy zones, highlighting abiotic factors’ relevance to predicting foraging behavior. Furthermore, wind reduced the range of load sizes that workers should select to maintain a similar rate of food intake and decreased the foraging rate by ~70% when wind speed increased 1 km/h. The results suggest that wind could negatively reduce the fitness of colonies and limit the geographic distribution of leaf-cutting ants. The model developed offers a complementary explanation of why load size in central-place foragers (i.e., animals that forage in a patch at some distance and then return resources to a central place) may not fit theoretical predictions. Although it would be necessary to adjust some parameter values, the model could also serve as a basis in studying the effects of other factors—environmental (e.g., temperature, rain, light), biotic (e.g., parasitoid attack, competitors) or anthropic (e.g., pesticides)—that influence central-place foragers. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">T</span>he load size selected by organisms depends on the costs of transportation, manipulation and discovery, and biotic constraints such as predation and competition. However, studies about the effect of abiotic factors on loading prey selection are few and limited to evaluation of how these factors affect animal movement. In regions characterized by strong and constant wind, leaf-cutting ants spend more time bringing resources to their nests. Wind negatively affects ant movement, decreasing their speed and blowing the ants off foraging trails. Considering this, Andrea Marina Alma and colleagues at the Laboratorio Ecotono has developed a mathematical model unifying theory, individual ant behavior, the effect of wind, and the underground tasks that determine load size. In addition, they have tested whether the model predictions agree with ant behavior, sampling the load size transported by workers in windy regions of Patagonia, Argentina. </p><p>They found that as wind speed at ground level increased from 0 to 2 km/h, load size decreased from 91 to 30 mm², a prediction that agreed with empirical data from windy zones, highlighting abiotic factors’ relevance to predicting foraging behavior. Furthermore, wind reduced the range of load sizes that workers should select to maintain a similar rate of food intake and decreased the foraging rate by ~70% when wind speed increased 1 km/h. </p><p>The results suggest that wind could negatively reduce the fitness of colonies and limit the geographic distribution of leaf-cutting ants. The model developed offers a complementary explanation of why load size in central-place foragers (i.e., animals that forage in a patch at some distance and then return resources to a central place) may not fit theoretical predictions. Although it would be necessary to adjust some parameter values, the model could also serve as a basis in studying the effects of other factors—environmental (e.g., temperature, rain, light), biotic (e.g., parasitoid attack, competitors) or anthropic (e.g., pesticides)—that influence central-place foragers. <a href="http://dx.doi.org/10.1086/692707">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Thu, 22 Jun 2017 05:00:00 GMT “Resource allocation and seed size selection in perennial plants under pollen limitation” http://amnat.org/an/newpapers/SepHuang.html Pollen limitation plays an important role in the ecology and evolution of seed size and adult survival in plants Pollen limitation of plant reproduction is becoming increasingly common in nature because of factors such as human disturbance, habitat loss or fragmentation, and climate change, which may reduce plant and pollinator abundance. Plants may adopt a variety of ways to cope with pollen limitation. For example, plants may try to attract more pollinator visits by increasing resource allocation to pollinator attraction. Plants may also overproduce ovules to capture the reproductive opportunities afforded by the rare flowers that receive unusually abundant pollen. However, the possibility that pollen limitation may change seed size has not been explored. Here, Huang, Burd, and Fan examine the effect of pollen limitation on resource allocation and the optimal seed size using an evolutionarily stable strategy resource allocation model in outcrossing perennial iteroparous plants. They find that under density-independent population growth, pollen limitation (i.e., a reduction in ovule fertilization rate) should increase the optimal seed size. At any level of pollen limitation (including none), the optimal seed size maximizes the ratio of juvenile survival rate to the resource investment needed to produce one seed (including both ovule production and seed provisioning), that is, the optimum maximizes the fitness effect per unit cost. Seed investment may affect allocation to post-breeding adult survival. In the model, pollen limitation increases individual seed size but decreases overall reproductive allocation, so that pollen limitation should also increase the optimal allocation to post-breeding adult survival. Under density-dependent population growth, the optimal seed size is inversely proportional to ovule fertilization rate. However, pollen limitation does not affect the optimal allocation to post-breeding adult survival and ovule production. The effect of pollen limitation on the optimal seed size also applies to semelparous plants. The model indicates that in addition to changes in resource allocation to pollen attraction and ovule production, plants may also increase seed size to cope with pollen limitation. Thus, the model introduces a novel element for understanding the consequences of the widespread phenomenon of pollen limitation. Because most plants have an ovule fertilization rate less than unity, alleviating pollen limitation may often decrease seed size and increase seed number. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>Pollen limitation plays an important role in the ecology and evolution of seed size and adult survival in plants </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">P</span>ollen limitation of plant reproduction is becoming increasingly common in nature because of factors such as human disturbance, habitat loss or fragmentation, and climate change, which may reduce plant and pollinator abundance. Plants may adopt a variety of ways to cope with pollen limitation. For example, plants may try to attract more pollinator visits by increasing resource allocation to pollinator attraction. Plants may also overproduce ovules to capture the reproductive opportunities afforded by the rare flowers that receive unusually abundant pollen. However, the possibility that pollen limitation may change seed size has not been explored. </p><p>Here, Huang, Burd, and Fan examine the effect of pollen limitation on resource allocation and the optimal seed size using an evolutionarily stable strategy resource allocation model in outcrossing perennial iteroparous plants. They find that under density-independent population growth, pollen limitation (i.e., a reduction in ovule fertilization rate) should increase the optimal seed size. At any level of pollen limitation (including none), the optimal seed size maximizes the ratio of juvenile survival rate to the resource investment needed to produce one seed (including both ovule production and seed provisioning), that is, the optimum maximizes the fitness effect per unit cost. Seed investment may affect allocation to post-breeding adult survival. In the model, pollen limitation increases individual seed size but decreases overall reproductive allocation, so that pollen limitation should also increase the optimal allocation to post-breeding adult survival. Under density-dependent population growth, the optimal seed size is inversely proportional to ovule fertilization rate. However, pollen limitation does not affect the optimal allocation to post-breeding adult survival and ovule production. The effect of pollen limitation on the optimal seed size also applies to semelparous plants. </p><p>The model indicates that in addition to changes in resource allocation to pollen attraction and ovule production, plants may also increase seed size to cope with pollen limitation. Thus, the model introduces a novel element for understanding the consequences of the widespread phenomenon of pollen limitation. Because most plants have an ovule fertilization rate less than unity, alleviating pollen limitation may often decrease seed size and increase seed number. <a href="http://dx.doi.org/10.1086/692543">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Tue, 20 Jun 2017 05:00:00 GMT “Sensory drive, color, and color vision” http://amnat.org/an/newpapers/AugPrice.html Without a doubt, the diversity of natural colors greatly enriches our lives. Without a doubt too, exactly why a plant or animal is the color it is remains one of the more vexing and least understood questions in nature. Twenty-five years ago in an article in the American Naturalist, John Endler synthesized research up to that time to argue that both an animal’s color and how an animal sees color are affected by the environment it lives in. But at that time, theory also suggested colors might be present simply because they induce favorable reactions in other members of the species. Much has happened over the past quarter-century. For example, we can make a good case that primates such as ourselves have better color vision than other mammals (especially in the red-green part of the spectrum) because it helped an ancient primate to distinguish edible fruits from green leaves in the rainforest. And following on from that, primates are the most colorful of mammals because their improved color vision allows them to distinguish amongst potential mates or rivals. So one approach to further our understanding might be to ask how and why color vision varies among different related species, and how this is associated with their colors. That is the research program Trevor Price has reviewed in an address appearing in The&nbsp;American Naturalist. It is a challenging yet exciting area. Color vision itself is a remarkably complex trait, with perception of an object’s color changing as the spectrum of background light changes, but staying roughly constant even as the spectrum of the illuminating light varies. However, we are making progress by getting at the nuts and bolts: studying the genes and developmental mechanisms that affect color vision. Opsin proteins in cone cells of the eye affect which wavelengths of light are best absorbed. Across fish and bird species, opsin differences can be explained partly by the color of light the species experiences, and in a few cases, so can color. In another 25 years we may understand why a robin is red and a blue jay blue. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">W</span>ithout a doubt, the diversity of natural colors greatly enriches our lives. Without a doubt too, exactly why a plant or animal is the color it is remains one of the more vexing and least understood questions in nature. Twenty-five years ago in an article in the American Naturalist, John Endler synthesized research up to that time to argue that both an animal’s color and how an animal sees color are affected by the environment it lives in. But at that time, theory also suggested colors might be present simply because they induce favorable reactions in other members of the species. Much has happened over the past quarter-century. For example, we can make a good case that primates such as ourselves have better color vision than other mammals (especially in the red-green part of the spectrum) because it helped an ancient primate to distinguish edible fruits from green leaves in the rainforest. And following on from that, primates are the most colorful of mammals because their improved color vision allows them to distinguish amongst potential mates or rivals. So one approach to further our understanding might be to ask how and why color vision varies among different related species, and how this is associated with their colors. That is the research program Trevor Price has reviewed in an address appearing in <i>The&nbsp;American Naturalist</i>. It is a challenging yet exciting area. Color vision itself is a remarkably complex trait, with perception of an object’s color changing as the spectrum of background light changes, but staying roughly constant even as the spectrum of the illuminating light varies. However, we are making progress by getting at the nuts and bolts: studying the genes and developmental mechanisms that affect color vision. Opsin proteins in cone cells of the eye affect which wavelengths of light are best absorbed. Across fish and bird species, opsin differences can be explained partly by the color of light the species experiences, and in a few cases, so can color. In another 25 years we may understand why a robin is red and a blue jay blue. <a href="http://dx.doi.org/10.1086/692535">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 16 Jun 2017 05:00:00 GMT Links to the ASN Policy Statements http://amnat.org/announcements/Policy.html Letter to the NSF about the Doctoral Dissertation Improvement Grant Program ASN Attends Congressional Visits Day 2017 Letter to the U.S. Congress on the Endangered Species Act Letter to the U.S. Congress on Plant Conservation Legislation Joint Societies&#39; Letter to the Trump Administration on Travel Restrictions <ul> <li> <h2 style="margin: 0px; padding: 0px; font-size: 24px; color: rgb(0, 88, 37); font-family: Georgia, Georgia, &quot;Times New Roman&quot;, Times, serif; line-height: 31.2px; text-decoration: none; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(235, 253, 255);"><a href="http://www.amnat.org/announcements/LTRDDIG.html">Letter to the NSF about the Doctoral Dissertation Improvement Grant Program</a></h2> </li> <li> <h2 style="margin: 0px; padding: 0px; font-size: 24px; color: rgb(0, 88, 37); font-family: Georgia, Georgia, &quot;Times New Roman&quot;, Times, serif; line-height: 31.2px; text-decoration: none; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(235, 253, 255);"><a href="http://www.amnat.org/announcements/ReportAIBS.html">ASN Attends Congressional Visits Day 2017</a></h2> </li> <li> <h2 style="margin: 0px; padding: 0px; font-size: 24px; color: rgb(0, 88, 37); font-family: Georgia, Georgia, &quot;Times New Roman&quot;, Times, serif; line-height: 31.2px; text-decoration: none; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(235, 253, 255);"><a href="http://www.amnat.org/announcements/LTRspecies.html">Letter to the U.S. Congress on the Endangered Species Act</a></h2> </li> <li> <h2 style="margin: 0px; padding: 0px; font-size: 24px; color: rgb(0, 88, 37); font-family: Georgia, Georgia, &quot;Times New Roman&quot;, Times, serif; line-height: 31.2px; text-decoration: none; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(235, 253, 255);"><a href="http://www.amnat.org/announcements/LTRplant.html">Letter to the U.S. Congress on Plant Conservation Legislation</a></h2> </li> <li> <h2 style="margin: 0px; padding: 0px; font-size: 24px; color: rgb(0, 88, 37); font-family: Georgia, Georgia, &quot;Times New Roman&quot;, Times, serif; line-height: 31.2px; text-decoration: none; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(235, 253, 255);"><a href="http://www.amnat.org/announcements/LTRvisa.html">Joint Societies&#39; Letter to the Trump Administration on Travel Restrictions</a></h2> </li> </ul> Fri, 09 Jun 2017 05:00:00 GMT “Predation risk reverses the potential effects of warming on plant-herbivore interactions by altering the relative strengths of trait- and density-mediated indirect interactions” http://amnat.org/an/newpapers/SepLemoine.html Elevated temperatures reduce the role of fear in herbivore foraging decisions Foraging is risky business for herbivores because it exposes them to significant predation risk. At the same time, however, herbivores must forage in order to maximize both their growth rates and number of offspring. This trade-off between feeding and hiding from predators dictates much of herbivore behavior and is determined by an herbivore’s metabolic rate and energetic needs. For ectothermic (i.e. cold-blooded) herbivores, like grasshoppers, caterpillars, or many fish species, metabolic rates increase with rising temperatures. Climate warming might therefore fundamentally alter the amount of predation risk herbivores are willing to accept in order to avoid starvation. In other words, rising temperatures will pose a dilemma to ectothermic herbivores: do they forage more intensely but risk being killed more frequently, or do they skip foraging to avoid predation but face increased starvation rates? A new modeling experiment by Nathan Lemoine, a research scientist at Colorado State University, demonstrates the consequences of rising temperatures on insect herbivores. At cool temperatures, herbivores have low metabolic rates and, as a result, there are few consequences for herbivores who skip a foraging bout to avoid predation. At high temperatures, herbivores experience considerably greater metabolic demands. Skipping foraging to avoid predation therefore imposes a great cost: the surviving herbivores are smaller and have fewer offspring. Furthermore, herbivores that choose to forage suffer incredibly high predation rates, with herbivore mortality rates nearing 100% in some scenarios. These results have profound implications for our understanding of how climate change will impact terrestrial ecosystems. The landscape of fear might cease to exist in the future as the threat of starvation overwhelms the threat of predation for herbivores, who suffer dramatically reduced population sizes due to increased predation rates. As a result, herbivore control of plant primary production might be substantially weaker in the future. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>Elevated temperatures reduce the role of fear in herbivore foraging decisions </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">F</span>oraging is risky business for herbivores because it exposes them to significant predation risk. At the same time, however, herbivores must forage in order to maximize both their growth rates and number of offspring. This trade-off between feeding and hiding from predators dictates much of herbivore behavior and is determined by an herbivore’s metabolic rate and energetic needs. For ectothermic (i.e. cold-blooded) herbivores, like grasshoppers, caterpillars, or many fish species, metabolic rates increase with rising temperatures. Climate warming might therefore fundamentally alter the amount of predation risk herbivores are willing to accept in order to avoid starvation. In other words, rising temperatures will pose a dilemma to ectothermic herbivores: do they forage more intensely but risk being killed more frequently, or do they skip foraging to avoid predation but face increased starvation rates? </p><p>A new modeling experiment by Nathan Lemoine, a research scientist at Colorado State University, demonstrates the consequences of rising temperatures on insect herbivores. At cool temperatures, herbivores have low metabolic rates and, as a result, there are few consequences for herbivores who skip a foraging bout to avoid predation. At high temperatures, herbivores experience considerably greater metabolic demands. Skipping foraging to avoid predation therefore imposes a great cost: the surviving herbivores are smaller and have fewer offspring. Furthermore, herbivores that choose to forage suffer incredibly high predation rates, with herbivore mortality rates nearing 100% in some scenarios. </p><p>These results have profound implications for our understanding of how climate change will impact terrestrial ecosystems. The landscape of fear might cease to exist in the future as the threat of starvation overwhelms the threat of predation for herbivores, who suffer dramatically reduced population sizes due to increased predation rates. As a result, herbivore control of plant primary production might be substantially weaker in the future. <a href="http://dx.doi.org/10.1086/692605">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 09 Jun 2017 05:00:00 GMT “The biased evolution of generation time” http://amnat.org/an/newpapers/AugVerin.html Long generation times could evolve neutrally as a consequence of turnover bias Evolution proceeds through the appearance and fixation of heritable changes such as genetic mutations. Selection informs us on the latter—how likely is a mutation that has appeared to reach fixation. Nonetheless, the appearance of mutations can also be important, but is often ignored in evolutionary studies. For instance, mutation biases—whereby some mutations are more likely to appear than others—are well known to impact molecular traits such as codon usage. The role of such biases in the evolution of phenotypic traits is unknown but presumably restricted. In this study, M&eacute;lissa Verin (now a PhD student in Munich) and her colleagues at the University of Lyon show that a different kind of bias can affect the evolution of phenotypic traits such as adult longevity or development time—in fact, any trait correlated with the generation time. They model the evolution of such traits in a context where none is given a selective advantage, to focus on the “appearance” part of the evolutionary process, and find that the genotypes with the longest generation times were the most likely to evolve. Their work provides a new, non-adaptive hypothesis for the evolution of species with long generation times. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>Long generation times could evolve neutrally as a consequence of turnover bias </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">E</span>volution proceeds through the appearance and fixation of heritable changes such as genetic mutations. Selection informs us on the latter&mdash;how likely is a mutation that has appeared to reach fixation. Nonetheless, the appearance of mutations can also be important, but is often ignored in evolutionary studies. For instance, mutation biases&mdash;whereby some mutations are more likely to appear than others&mdash;are well known to impact molecular traits such as codon usage. The role of such biases in the evolution of phenotypic traits is unknown but presumably restricted.</p> <p>In this study, M&eacute;lissa Verin (now a PhD student in Munich) and her colleagues at the University of Lyon show that a different kind of bias can affect the evolution of phenotypic traits such as adult longevity or development time&mdash;in fact, any trait correlated with the generation time. They model the evolution of such traits in a context where none is given a selective advantage, to focus on the &ldquo;appearance&rdquo; part of the evolutionary process, and find that the genotypes with the longest generation times were the most likely to evolve. Their work provides a new, non-adaptive hypothesis for the evolution of species with long generation times. <a href="http://dx.doi.org/10.1086/692324">Read&nbsp;the&nbsp;Article</a></p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"><span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Fri, 09 Jun 2017 05:00:00 GMT Letter to the NSF about the Doctoral Dissertation Improvement Grant Program http://amnat.org/announcements/LTRDDIG.html France C&oacute;rdova Director, National Science Foundation James Olds Assistant Director, Directorate of Biological Sciences National Science Foundation Dear Director C&oacute;rdova and Assistant Director Olds, As representatives of the American Society of Naturalists, the Society for the Study of Evolution, and the Society of Systematic Biologists, we are writing to urge NSF to reinstate the Doctoral Dissertation Improvement Grant (DDIG) program in the Division of Environmental Biology and the Division of Integrative Organismal Systems.&nbsp; DDIGs are a strategic investment in the future of our fields, contributing to the development of independent research skills in the junior cohorts who will be the next innovators. DDIGs offer graduate students independence in their research, mentorship opportunities, and resources to network and disseminate their findings. Having their own financial resources permits students to prioritize their research goals and invest in directions they find most promising, directly supporting the development of scientific creativity and leadership for the future of the country. Students who have received DDIGs have had valuable training in grant writing, administering grant funding, crafting independent research programs, and mentoring.&nbsp; These are all essential skills that represent the essence of our goals for training students in our fields.&nbsp; There are few other avenues whereby students can obtain such valuable experience, and DDIGs offer unusually high return on the modest financial investment.&nbsp; Without the DDIG program, the junior members of our societies and in related fields will be denied valuable opportunities for their intellectual and professional development.&nbsp; The termination of the DDIG program will have long-lasting adverse consequences to the intellectual development of young scientists in ecology, evolution, and organismal biology. &nbsp; Representing the thousands of members in our respective societies, we offer to help find solutions to support the DDIG program and maintain a sound, fiscally responsible, and efficient program in support of student research. The DDIG program is a very important investment in the scientific future of the country. Sincerely, Kathleen Donohue President, The American Society of Naturalists Sarah Otto President, Society for the Study of Evolution Luke Harmon President, Society for Systematic Biologists <p>France C&oacute;rdova<br /> Director, National Science Foundation</p> <p>James Olds<br /> Assistant Director, Directorate of Biological Sciences<br /> National Science Foundation</p> <p>Dear Director C&oacute;rdova and Assistant Director Olds,</p> <p>As representatives of the American Society of Naturalists, the Society for the Study of Evolution, and the Society of Systematic Biologists, we are writing to urge NSF to reinstate the Doctoral Dissertation Improvement Grant (DDIG) program in the Division of Environmental Biology and the Division of Integrative Organismal Systems.&nbsp; DDIGs are a strategic investment in the future of our fields, contributing to the development of independent research skills in the junior cohorts who will be the next innovators.</p> <p>DDIGs offer graduate students independence in their research, mentorship opportunities, and resources to network and disseminate their findings. Having their own financial resources permits students to prioritize their research goals and invest in directions they find most promising, directly supporting the development of scientific creativity and leadership for the future of the country.</p> <p> Students who have received DDIGs have had valuable training in grant writing, administering grant funding, crafting independent research programs, and mentoring.&nbsp; These are all essential skills that represent the essence of our goals for training students in our fields.&nbsp; There are few other avenues whereby students can obtain such valuable experience, and DDIGs offer unusually high return on the modest financial investment.&nbsp; Without the DDIG program, the junior members of our societies and in related fields will be denied valuable opportunities for their intellectual and professional development.&nbsp; The termination of the DDIG program will have long-lasting adverse consequences to the intellectual development of young scientists in ecology, evolution, and organismal biology. &nbsp;</p> <p> Representing the thousands of members in our respective societies, we offer to help find solutions to support the DDIG program and maintain a sound, fiscally responsible, and efficient program in support of student research. The DDIG program is a very important investment in the scientific future of the country.</p> <p> Sincerely,</p> <p>Kathleen Donohue<br /> President, The American Society of Naturalists</p> <p>Sarah Otto<br /> President, Society for the Study of Evolution</p> <p>Luke Harmon<br /> President, Society for Systematic Biologists</p> Fri, 09 Jun 2017 05:00:00 GMT “The evolution of energetic scaling across the vertebrate tree of life” http://amnat.org/an/newpapers/AugUyeda-A.html Metabolic scaling coefficients evolve across the vertebrate tree of life Abstract Metabolism is the link between ecology and physiology—it dictates the flow of energy through individuals and across trophic levels. Much of the predictive power of metabolic theories of ecology derives from the scaling relationship between organismal size and metabolic rate. There is growing evidence that this scaling relationship is not universal, but we have little knowledge of how it has evolved over macroevolutionary time. Here we develop a novel phylogenetic comparative method to investigate how often and in which clades the macroevolutionary dynamics of the metabolic scaling have changed. We find strong evidence that the metabolic scaling relationship has shifted multiple times across the vertebrate phylogeny. However, shifts are rare and otherwise are strongly constrained. Importantly, both the estimated slope and intercept values vary widely across regimes, with slopes that spanned across theoretically predicted values such as 2/3 or 3/4. We further tested whether traits such as ecto-/endothermy, genome size, and quadratic curvature with body mass (i.e., energetic constraints at extreme body sizes) could explain the observed pattern of shifts. Though these factors help explain some of the variation in scaling parameters, much of the remaining variation remains elusive. Our results lay the groundwork for further exploration of the evolutionary and ecological drivers of major transitions in metabolic strategy and for harnessing this information to improve macroecological predictions. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>Metabolic scaling coefficients evolve across the vertebrate tree of life </b></p><h3>Abstract</h3> <p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">M</span>etabolism is the link between ecology and physiology&mdash;it dictates the flow of energy through individuals and across trophic levels. Much of the predictive power of metabolic theories of ecology derives from the scaling relationship between organismal size and metabolic rate. There is growing evidence that this scaling relationship is not universal, but we have little knowledge of how it has evolved over macroevolutionary time. Here we develop a novel phylogenetic comparative method to investigate how often and in which clades the macroevolutionary dynamics of the metabolic scaling have changed. We find strong evidence that the metabolic scaling relationship has shifted multiple times across the vertebrate phylogeny. However, shifts are rare and otherwise are strongly constrained. Importantly, both the estimated slope and intercept values vary widely across regimes, with slopes that spanned across theoretically predicted values such as 2/3 or 3/4. We further tested whether traits such as ecto-/endothermy, genome size, and quadratic curvature with body mass (i.e., energetic constraints at extreme body sizes) could explain the observed pattern of shifts. Though these factors help explain some of the variation in scaling parameters, much of the remaining variation remains elusive. Our results lay the groundwork for further exploration of the evolutionary and ecological drivers of major transitions in metabolic strategy and for harnessing this information to improve macroecological predictions. <a href="http://dx.doi.org/10.1086/692326">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Wed, 31 May 2017 05:00:00 GMT “Geographical variation in community divergence: insights from tropical forest monodominance by ectomycorrhizal trees” http://amnat.org/an/newpapers/VPFukami.html A new study suggests the answer to this question may lie in the fungi that grow in tree roots Tropical forests are the quintessence of biodiversity. Thousands of tree species are found in Borneo and the Amazon, for example. However, some of these forests contain distinct areas dominated by just one tree species. Ranging in size from one to several thousand hectares, these monodominant stands are puzzling because they occur within a vast tract of land that is otherwise co-dominated by many species of trees. How do monodominant stands arise, and what keeps them from being colonized by the many species that must be sending millions of seeds from adjacent areas? One possible answer is the fungi that colonize the roots of monodominant trees. These fungi help trees grow by making nutrients in the soil more readily available to the trees. It is thought that the trees that host one type of root-colonizing fungi, called ectomycorrhizal fungi, form monodominant stands if they happen to become established in a disturbed site earlier than other species because the soil is then made more favorable to the ectomycorrhizal trees than to other trees. However, monodominant stands arise only in some tropical regions, and not others. For example, we find them in Africa and South America, but not in Southeast Asia. Why is that? To answer this question, a group of researchers from Stanford University, the University of Nebraska, the University of California at Los Angeles and at Berkeley, and Florida International University used computer simulation models as a tool to develop a new hypothesis. The proposed hypothesis is that in regions with just a few tree species that host ectomycorrhizal fungi, such as Africa and South America, these trees evolve to acquire characteristics that closely match the environment. As a result, they can successfully compete against other species to form monodominant stands via their association with the fungi. By contrast, in regions with many tree species that host ectomycorrhizal fungi, such as Southeast Asia, these species maintain a variety of characteristics, with no species having the characteristics that enable them to form monodominance. This research provides a new idea to explain why biodiversity is distributed over space the way it is in tropical forests. Read&nbsp;the&nbsp;Article More forthcoming papers &raquo; <p><b>A new study suggests the answer to this question may lie in the fungi that grow in tree roots </b></p><p><span style="float: left; font-size: 40px; line-height: 25px; padding-top: 4px; padding-right: 2px; padding-left: 2px; font-family: Garamond; font-weight: bold;">T</span>ropical forests are the quintessence of biodiversity. Thousands of tree species are found in Borneo and the Amazon, for example. However, some of these forests contain distinct areas dominated by just one tree species. Ranging in size from one to several thousand hectares, these monodominant stands are puzzling because they occur within a vast tract of land that is otherwise co-dominated by many species of trees. How do monodominant stands arise, and what keeps them from being colonized by the many species that must be sending millions of seeds from adjacent areas? </p><p>One possible answer is the fungi that colonize the roots of monodominant trees. These fungi help trees grow by making nutrients in the soil more readily available to the trees. It is thought that the trees that host one type of root-colonizing fungi, called ectomycorrhizal fungi, form monodominant stands if they happen to become established in a disturbed site earlier than other species because the soil is then made more favorable to the ectomycorrhizal trees than to other trees. </p><p>However, monodominant stands arise only in some tropical regions, and not others. For example, we find them in Africa and South America, but not in Southeast Asia. Why is that? To answer this question, a group of researchers from Stanford University, the University of Nebraska, the University of California at Los Angeles and at Berkeley, and Florida International University used computer simulation models as a tool to develop a new hypothesis. </p><p>The proposed hypothesis is that in regions with just a few tree species that host ectomycorrhizal fungi, such as Africa and South America, these trees evolve to acquire characteristics that closely match the environment. As a result, they can successfully compete against other species to form monodominant stands via their association with the fungi. By contrast, in regions with many tree species that host ectomycorrhizal fungi, such as Southeast Asia, these species maintain a variety of characteristics, with no species having the characteristics that enable them to form monodominance. This research provides a new idea to explain why biodiversity is distributed over space the way it is in tropical forests. <a href="http://dx.doi.org/10.1086/692439">Read&nbsp;the&nbsp;Article</a> </p> <div style="float: right;"><a href="http://www.amnat.org/an/newpapers.html"> <span style="font-size: large; font-family: Georgia;"><i>More forthcoming papers</i> &raquo;</span></a></div> Mon, 22 May 2017 05:00:00 GMT