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Researchers have found new clues to how plants evolved to withstand wintry weather. In a study, which appeared December 22 in the journal Nature, researchers constructed an evolutionary tree of more than 32,000 species of flowering plants — the largest time-scaled evolutionary tree to date. Combining their evolutionary tree with freezing exposure records and leaf and stem data for thousands of species, the researchers were able to reconstruct how plants evolved to cope with cold as they spread across the globe. Read the full story.Citation: Zanne, A., et al. 2013. Three keys to the radiation of angiosperms into freezing environments. Nature. [Online]
The same algorithm used to find tunes in music retrieval systems has been successfully applied in identifying the signature whistles of dolphins, affording a new time-saving device for research into the world of dolphin communication. A study, published Oct. 23 in the journal PLOS ONE, describes a new method. Read the full story.Citation: Kershenbaum A, Sayigh LS, Janik VM. 2013. The encoding of individual identity in dolphin signature whistles: how much information is needed? PLOS ONE. [Online]
Although a turtle's home may be on its back, some North American turtles face an uncertain future as a warming climate threatens to reduce their suitable habitat. A new study that reconstructs the effects of past climatic changes on 59 species of North American turtles finds that the centers of the turtles’ ranges shifted an average of 45 miles for each degree of warming or cooling. While some species were able to find widespread suitable climate, other species, many of which today are endangered, were left with only minimal habitat. Read the full story.Citation: Rödder D, Lawing AM, Flecks M, Ahmadzadeh F, Dambach J, Engler JO, Habel JC, Hartmann T, Hörnes D, Ihlow F, Schiedelko K, Stiels D, Polly DP. 2013. Evaluating the significance of paleophylogeographic species distribution models in reconstructing quaternary range-shifts of Nearctic Chelonians. PLOS ONE. [Online]
The instability of large, complex societies is a predictable phenomenon, according to a new mathematical model that explores the emergence of early human societies via warfare. Capturing hundreds of years of human history, the model reveals the dynamical nature of societies, which can be difficult to uncover in archaeological data. Read the full story.Citation: Turchin P, Currie T, Turner E, Gavrilets S. 2013. War, space, and the evolution of Old World complex societies. PNAS. [Online]
KNOXVILLE - Two Tennessee high school students have now done what many scientists strive for: publishing their research in a top science journal. Dalton Chaffee and Hayes Griffin began their study on mate choice, which appears this week in the journal Evolution, between their junior and senior years at Bearden High School in Knoxville, TN. The students wanted to know why individuals choose the mates they choose and worked with their mentor R. Tucker Gilman, then a postdoctoral research fellow at the National Institute for Mathematical and Biological Synthesis at the University of Tennessee, to find out. Read the full story.Citation: Chaffee DW, Hayes G, Gilman RT. 2013. Sexual imprinting: What strategies should we expect to see in nature? Evolution. [Online]
|Credit: Peter Yanoviak|
Manipulation is often thought of as morally repugnant, but it might be particularly likely to cause the evolution of helpful or altruistic behavior, according to a new study. In a study published online in the journal American Naturalist, the researchers developed a mathematical model showing that resistance to manipulation may often fail to evolve, making helping particularly likely to arise from manipulation itself. Read the full story.Citation: González-Forero M, Gavrilets S. 2013. Evolution of manipulated behavior. The American Naturalist.
Article is in press: DOI: 10.1086/671932
|Credit: Mathieu Joron|
When a new species emerges following adaptive changes to its local environment, the process of choosing a mate can help protect the new species' genetic identity and increase the likelihood of its survival. But of the many observable traits in a potential mate, which particular traits does a female tend to prefer? A new study from the National Institute for Mathematical and Biological Synthesis finds that a female's mating decisions are largely based on traits that reflect fitness or those that help males perform well under the local ecological conditions. Read the full story.Citation: Thibert-Plante X, Gavrilets S. 2013. Evolution of mate choice and the so called magic traits in ecological speciation. Ecology Letters. DOI: 10.1111/ele.12131 [Online]
Just as humans can follow complex social situations in deciding whom to befriend or to abandon, it turns out that animals use the same level of sophistication in judging social configurations, according to a new study that advances our understanding of the structure of animal social networks. Read the full story.Citation: Ilany A, Barocas A, Koren L, Kam M, Geffen E. 2013. Structural balance in the social networks of a wild mammal. Animal Behaviour. Published [online] 22 April 2013.
Malaria, the leading cause of death among children in Africa, could be eliminated if three-fourths of the population used insecticide-treated bed nets, according to a new NIMBioS study.
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Although the current Supreme Court has been criticized for its lack of diversity on the bench, the Court is actually more diverse overall today than ever in history, according to a new study that borrows statistical methods from ecology to reveal a more precise picture of diversity.
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Since the mid-nineteenth century, maps have helped elucidate the deadly mysteries of diseases like cholera and yellow fever. Yet today’s global mapping of infectious diseases is considerably unreliable and may do little to inform the control of potential outbreaks, according to a new systematic mapping review of all clinically important infectious diseases known to humans.
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Epigenetics – how gene expression is regulated by temporary switches, called epi-marks – appears to be a critical and overlooked factor contributing to the long-standing puzzle of why homosexuality occurs. According to the study, published online today in The Quarterly Review of Biology, sex-specific epi-marks, which normally do not pass between generations and are thus "erased," can lead to homosexuality when they escape erasure and are transmitted from father to daughter or mother to son.
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When foot-and-mouth disease swept through the British countryside
in early 2001, more than 10 million sheep, cattle and pigs were
slaughtered to control the disease. Despite the devastation, the disease
was contained within ten months in part owing to the availability in
that country of finely detailed farm data, which enabled mathematical
modelers to make accurate predictions about the spread of the disease
and suggest optimal ways of managing it. Should foot-and-mouth disease
occur in the United States today where privacy laws restrict the
accessibility of data, making predictions about the disease might not be
so easy, according to a new study that weighs the costs of privacy in
preventing disease outbreaks.
Read the full story.
With new national anti-bullying ads urging parents to teach their kids to speak up if they witness bullying, one researcher has found that in humans' evolutionary past at least, helping the victim of a bully hastened our species' movement toward a more egalitarian society. The drive to help the weaker group members led to a dramatic reduction in group inequality and eventually enabled humans to develop widespread cooperation, empathy, compassion and egalitarian moral values, according to the paper which appears today in the Proceedings of the National Academy of Sciences. Read the full story.
Johne's disease (JD) is a chronic intestinal infection affecting ruminants, and according to the U.S. dairy industry, causes an estimated annual loss of $200 million. In infected cattle, the prolonged and slow infection causes rapid weight loss and diarrhea, which in turn causes decreased milk production and premature culling of clinically infected animals.
In early human evolution, when faithful females began to choose good providers as mates, pair-bonding replaced promiscuity, laying the foundation for the emergence of the institution of the modern family, a new study finds.
Forests are home to a wide variety of plants that provide an array of services to humans. Non-timber forest products are traded as valuable commodities on the international market in the form of edible products, floral greenery, and herbal medicines, among many other products. But the over-harvesting of these wild plants has great ecological consequences.
When individuals rely on the presence of others to increase their chances of survival and reproduction, the emergence of adaptations that reduce this dependence can help rescue small populations from extinction. Exploring the ecological and evolutionary consequences of the relationship between individual fitness and population size is the focus of Andrew Kanarek's research as a postdoctoral fellow at NIMBioS.
Dr. Maud Lélu. It was where her mother became infected with the parasite Toxoplasma gondii while pregnant with Lélu, and where, 27 years later, Lélu successfully defended her doctoral dissertation on the transmission dynamics of the parasite. It was pure coincidence, Lélu said, that she came to study T. gondii, which chronically infects an estimated one-third of the total global population, including Lélu's mother, and Lélu herself, who tested positive for the parasite as an adult.
Does the way an organism moves through an ecological community affect its survivability? The question is one that NIMBioS postdoctoral fellow Daniel Ryan is trying to answer as a part of his research in the field of movement ecology, a discipline that considers all aspects of movement behavior in organisms. From sea turtles to salmon who return home after swimming thousands of miles away, from roaming elephants, migrating birds, spreading bacteria and dispersing seeds, the research attempts to answer why, how, where and when organisms move.
NIMBioS postdoctoral fellow Juanjuan "J.J." Chai is conducting research in phylogenetics, which studies evolutionary relatedness among groups of organisms through molecular sequencing data and morphological data. Biologists estimate that there are about 5 to 100 million species of organisms living on Earth today, and their genealogical relationships can be represented by evolutionary trees. Chai is working to solve problems related to the methods used in phylogenetics.
In nature, how do host species survive parasite attacks? This has not been well understood, until now. A new mathematical model shows that when a host and its parasite each have multiple traits governing their interaction, the host has a unique evolutionary advantage that helps it survive. The results are important because they might help explain how humans as well as plants and animals evolve to withstand parasite onslaught. Two postdoctoral fellows at NIMBioS are among the authors of the research, which was published in the March 4 online edition of Nature.
Growing up in Cameroon, Africa, Dr. Calistus Ngonghala witnessed firsthand the devastation poverty and diseases like malaria and HIV/AIDS can bring to a community. His personal experiences have inspired his research in developing mathematical models to help fight malaria and other pandemics and in investigating how health interventions can alleviate vicious cycles of poverty and disease.
Whether a species can evolve to survive climate change may depend on the biodiversity of its ecological community, according to a new mathematical model that simulates the effect of climate change on plants and pollinators.
Protease inhibitor drugs are one of the major weapons in the fight against HIV, the virus that causes AIDS, but their effectiveness is limited as the virus mutates and develops resistance to the drugs over time. Now a new tool has been developed to help predict the location of the mutations that lead to drug resistance.
Mate choice, competition, and the variety of resources available are the key factors influencing how a species evolves into separate species, according to a new mathematical model that integrates all three factors to reveal the dynamics at play in a process called sympatric speciation.
The symbiosis between legume plants and the bacteria that inhabit their roots seems sweet. These bacteria — called rhizobia — turn nitrogen molecules from the air into a form that the plant can use and, in return, feast on carbohydrates the plant provides. But conflicting interests lurk beneath the surface and can undermine such cooperation, as both parties might prefer to benefit without paying their dues. A new study shows that the process determining the exchange rate of nitrogen and carbohydrates has profound effects on how cooperation can be maintained between legumes and rhizobia.
Species pairs that disappear through hybridization after human-induced changes to the environment can reemerge if the disturbance is removed, according to a new mathematical model that shows the conditions under which reemergence might happen. The findings, published in the journal Evolution, are important for conservationists and ecosystem managers interested in preserving, or even restoring, systems that have been disturbed by human activity.
How does brain mass vary with body mass in a group of species? How does social behavior in insects vary with the number of chromosomes? These are the sorts of questions biologists might ask when studying a species. One method of exploring these questions is to build comparative models to analyze data in evolutionary relationships. NIMBioS postdoctoral researcher Dwueng-Chwuan "Tony" Jhwueng designs new phylogenetic comparative methods for comparative analysis under non-tree-like or network evolution.
Influenza pandemics can mean that schools close and travellers stay home. But is severing social and business interactions really better than taking a chance on getting sick? "Infectious disease can mean making trade-offs between the risks and rewards of meeting others," says Eli Fenichel, Arizona State University assistant professor and co-organizer of a transdisciplinary working group at NIMBioS that has developed a better model for understanding the role human decisons play in the spread of disease. A study describing the group's work appears in the journal Proceedings of the National Academy of Sciences (PNAS).
Culling will not stop the spread of a deadly fungus that is threatening to wipe out hibernating bats in North America, according to a new mathematical model. The new model examines how white-nose syndrome is passed from bat to bat and concludes that culling would not work because of the complexity of bat life history and because the fungal pathogen occurs in the caves and mines where the bats live.
NIMBioS postdoctoral fellow Emily Moran is interested in learning about how plants respond to changes in their environment. Moran investigates the impact of increasing CO2 on inter-genotype competition and plant-insect interactions in aspen forests in order to develop a modeling framework that could be applied to other forest communities. In an interview with NIMBioS, Moran explains her research and how she became interested in science and the field of ecology.
The instability of large, complex societies is a predictable phenomenon, according to a new mathematical model that explores the emergence of early human societies via warfare. Capturing hundreds of years of human history, the model reveals the dynamical nature of societies, which can be difficult to uncover in archaeological data.
NIMBioS postdoctoral fellow Tom Ingersoll is collaborating with fellow bat enthusiasts to understand the cause of and predict the spread of White-Nose Syndrome (WNS) in bat populations. Since first discovered in a cave in upstate New York in 2006, WNS has killed an estimated one million bats in caves and mines in North America. New research predicts regional extinctions of the most common bat species, the little brown bat, within two decades due to WNS. In an interview with NIMBioS, Ingersoll explains his research and how he became interested in the mighty bat.
When two individuals face off in conflict, the classic problem in evolutionary biology known as the prisoner's dilemma says that the individuals are not likely to cooperate even if it is in their best interests to do so. But a new study suggests that with incentives to cooperate, natural selection can minimize conflict, changing the game from one of pure conflict to one of partial cooperation.
Plants and animals are constantly evolving in response to other species with whom they interact. This process known as coevolution is fundamental in ecology and evolution, but little is known about how it works and how it shapes species and ecological communities. NIMBioS postdoctoral fellow Tucker Gilman is developing a modeling framework to explore the relationship between coevolution and speciation.
Biologists have long thought that interactions between plants and pollinating insects hasten evolutionary changes and promote biological diversity. However, new findings show that some interactions between plants and pollinators are less likely to increase diversity than previously thought, and in some instances, reduce it.
In an interview at the National Institute for Mathematical and Biological Synthesis, Assistant Professor of Mathematics at Maryville College Dr. Maria Siopsis explains why mathematics is a critical skill for biology students. Click here to view the video. (3 min 39 sec)
At the National Institute for Mathematical and Biological Synthesis, four scientists have gathered from around the world to determine optimal strategies for designing and managing marine and terrestrial reserves. Click here to view the video. (6 min 23 sec)
Dr. William Godsoe is a postdoctoral fellow at the National Institute for Mathematical and Biological Synthesis (NIMBioS). He uses probability theory to examine relationships between a species' niche and its geographic distribution. For more information about Dr. Godsoe's work, click here. To view the video click here. (3 min 51 sec)
Dr. Erol Akçay is a postdoctoral fellow at the National Institute for Mathematical and Biological Synthesis (NIMBioS). He investigates the dynamics of cooperation and conflict in animal social behavior and ecological mutualisms. Click here to view the video. (4 min 01 sec)
Dr. Folashade Agusto is a postdoctoral fellow at the National Institute for Mathematical and Biological Synthesis (NIMBioS). She conducts research involving mathematical analysis and optimal control of transmission dynamics of infectious diseases, focusing specifically on bovine tuberculosis, malaria and avian influenza. Click here to view the video. (1 min 53 sec)
Dr. Xavier Thibert-Plante is a postdoctoral researcher at the National Institute for Mathematical and Biological Synthesis (NIMBioS). He studies the impact of climate change on biodiversity, specifically the evolution of biodiversity and the process of biodiversification in a changing environment. Click here to view the video. (2 min 11 sec)
Dr. Sharon Bewick is a postdoctoral researcher at the National Institute for Mathematical and Biological Synthesis (NIMBioS). She studies how different ant species interact and how their interactions affect forest plant composition. She focuses particularly on how ant communities might be affected by disturbances in the global climate. For more information about Dr. Bewick's research, click here. To view the video, click here. (2 min 23 sec)
Dr. Yi Mao is a postdoctoral researcher at the National Institute for Mathematical and Biological Synthesis. She studies enzymatic protein's role in biological energy production and the physical principles that drive protein evolution. Because the origins of many diseases lie in the malfunction of proteins, a better understanding of how proteins behave could lead to new discoveries in medicine. Click here to view the video. (1 min 12 sec)
The rate of climate change is happening so fast that many species cannot adapt quickly enough and risk extinction. Dr. Thibert-Plante studies the interaction between ecological and evolutionary forces and their impact in shaping the planet's biodiversity.
The transition from colonies of individual cells to multicellular organisms can be achieved relatively rapidly, within one million generations, according to a new mathematical model that simplifies our understanding of this process.
A new commentary on the nature of pathogens is raising startling new questions about the role that fundamental science research on evolution plays in the understanding of emerging disease.
Separate species that live in radically different environments don't necessarily also have different ecological niches. This is the finding of a new study investigating the accuracy of current statistical tests that use models of geographic distributions to infer changes in environmental requirements.
Feral swine have been described as the most worrisome of non-native species in the Great Smoky Mountains National Park. These free-roaming pigs not only root out native plants and destroy natural habitats, but can also carry disease, such as pseudo-rabies, which is often fatal if transmitted to other wild and domestic animals.
Biologists have a rich array of quantitative tools for analyzing the genetics and evolution of traits, especially when the traits can be described by one or a few measurements. But describing some traits, such as gene expression profiles or life history patterns, is far more complex, often defined as a mathematical function of some other variable, such as body size as a function of age.
Although largely eradicated in the United States, the scourge of bovine tuberculosis continues to devastate cattle herds and other animals in parts of the developing world. The disease is also still a threat to public health where it can be transmitted via contact with infected animals and by consuming unpasteurized milk. Folashade Agusto knows firsthand of the devastation in her home country of Nigeria, where few control measures are in place to help eradicate bovine tuberculosis (TB). A postdoctoral fellow at NIMBioS, Agusto's research focuses on developing mathematical models to analyze the transmission of bovine TB in cattle, wildlife and humans.
Fire is often thought of as something that trees should be protected from, but a new study suggests that some trees may themselves contribute to the likelihood of wildfires in order to promote their own abundance at the expense of their competitors. The study, which appears in the December 2009 issue of The American Naturalist, finds that positive feedback loops between fire and trees associated with savannas can make fires more likely in these ecosystems.
As the planet warms, scientists have observed a radical disruption in the geographic distribution of thousands of animals and plants, which has unknown consequences for species survival. William Godsoe, postdoctoral fellow at the NIMBioS, studies the statistical relationships between a species ecological requirements, or niche, and its distribution, which offers a way to predict and mitigate ecological challenges facing the plant, such as climate change, habitat loss and species invasion.
In the course of a day, animals cooperate in a myriad different ways in order to increase their, and their species, chances of survival. In many species, for example, raising offspring requires help and cooperation from multiple individuals, and fending off predators can often be more effective when animals cooperate together as a herd.
Dr. Sharon Bewick studies how ant communities might be affected by disturbances in the global climate as a part of her research as a postdoctoral fellow at NIMBioS. She also wants to know how temperature changes might affect the delicately balanced ecosystems in which ants live.
As a short-term visitor to NIMBioS, Dr. Rene Salinas' research focuses on developing computer models that simulate changes in the black bear population in eastern Tennessee and western North Carolina. The model could be used by wildlife managers to help determine the best strategy for minimizing bear-human conflict while maintaining a sustainable bear population.
Proteins are the workhorses of biological processes. Because the origins of many diseases lie in the malfunction of proteins, a better understanding of how proteins behave could lead to new discoveries in medicine. At NIMBioS, postdoctoral fellow Yi Mao develops mathematical theories and algorithms to analyze bio-molecular systems, such as proteins.
U.S. authorities working to eradicate the spread of tuberculosis in cattle might benefit from predictive modeling approaches developed for European agricultural systems where more detailed animal movement data are available, according to summary findings from the first NIMBioS Investigative Workshop on Modeling Bovine Tuberculosis held July 7-9.
Consider the case of the three-spine stickleback. These tiny fish that thrive in oceans and in fresh water might appear to be the same, yet ecologists are finding that they are actually a diverse collection of highly specialized individuals. Understanding the causes and consequences of such ecological variation was the goal of a group of scientists who met at NIMBioS July 27-29.
A primary concern for wildlife managers tackling white-nose syndrome in bats is the ability to predict when and where in the United States the killer fungus will strike next, according to summary findings from the first NIMBioS Investigative Workshop on Modeling White Nose Syndrome (WNS) held June 30- July 2.
Plotting Herds to Eradicate Bovine Tuberculosis
Searching for Solutions to Evolutionary Puzzles
Unraveling the Mystery of White-Nose Syndrome
Examining Human Behavior and the Threat of Disease
Tackling a Math Problem for Ecology