NIMBioS Tuesday Seminar Series
In conjunction with the interdisciplinary activities of the National Institute for Mathematical and Biological Synthesis (NIMBioS), a seminar series will be hosted at NIMBioS every other Tuesday at 3:30 p.m. in the NIMBioS Lecture Hall on the 4th floor of 1534 White Ave., Suite 400 Seminar speakers will focus on their research initiatives at the interface of mathematics and many areas of the life sciences. Light refreshments will be served starting at 3 p.m. The below schedule will be supplemented as additional speakers are added.
Time: Tue 9/8 3:30 pm
Speaker: Dr. Erol Akçay, NIMBIoS Postdoc
Topic:The Evolution of Games and How to Play Them
Abstract: Evolutionary game theory is one of the main theoretical tools for studying the evolution of social behaviors. In this talk, I will present two models that develop a new approach to how games and evolution are modeled. This approach explicitly and separately models both the behavioral and evolutionary dynamics of an interaction, and integrates these two. The first model treats individuals in a social interaction that are motivated by their internal objectives. The results of the interaction affect individuals’ fitness, which leads to evolutionary selection pressures on the objective functions of individuals. We show that even in a game with total conflict between individuals’ payoffs, the evolutionarily stable objectives can be such that individuals aim to increase their partner’s payoff as well as their own. In the second model, I treat the evolution of the game itself, using a population genetics model for traits that affect the payoffs in a simple, bimatrix game.
Time: Tue 9/15 3:30 pm
Speaker: Carrie Manore, Oregon State University and Los Alamos National Laboratory
Topic:How Mathematical Models Can Help Control the Spread of Animal Diseases
Abstract: Animal diseases, such as foot-and-mouth disease and avian flu, are increasingly important in world economics, national security, and biodiversity. Rinderpest is an important animal disease related to human measles. It is a highly virulent and often lethal virus affecting cloven-hoofed animals such as cattle, sheep, and pigs. Rinderpest pandemics have caused wide-spread herd loss in Europe and Africa. If the disease enters the United States, it could be devastating to animal agriculture and the economy. To help prepare for this possibility, we create a spatially explicit stochastic model for multi-host animal diseases to better understand their spread in the United States. We explore the effectiveness of mitigation strategies such as quarantine, vaccination, and culling in a case study on rinderpest. Spread of rinderpest is modeled using county-level data and animal transportation rates to capture the within-county and between-county behavior. We compare different mitigation strategies and analyze the sensitivity of final epidemic size to these strategies in order to minimize loss due to an outbreak of rinderpest. Generalizations of control strategies for rinderpest are effective for other contagious animal diseases, such as foot and mouth disease.
Time: Tue 9/22 3:30 pm
Speaker: Dr. Sharon Bewick, NIMBIoS Postdoc
Topic:Modeling Local Community Responses to Climate Change
Abstract: I will be talking about the development of a mechanistic mathematical framework that models both competitive and mutualistic interspecific interactions with the goal of interpreting community dynamics and altered community structure under a warming regime. In particular, I will focus on climatic change as it affects ant communities in the temperate forests of eastern North America. To that end, the primary interspecific interactions that I will be discussing will relate to competition between ants for food resources. Previous models have considered competitive interactions between ants in terms of dominance-discovery tradeoffs. Certainly, global climate change may perturb both the dominance relationships between species and/or the discovery abilities of individual species, and this may have predictable consequences on community composition. More recently, however, several empirical studies have suggested that a dominance-thermal tolerance tradeoff may be more important than a dominance-discovery tradeoff, at least in the temperate forests of eastern North America. With this tradeoff, the impact of global climate change is even more obvious. I will therefore discuss the development of mechanistic mathematical models that capture the features of dominance-thermal tolerance tradeoffs and the possibility of using these models to predict community composition, both under current climatic conditions and under a warming regime. Finally, I will briefly touch on aspects related to modeling the impact that the ant community has on the plant community through ant-plant seed dispersal mutualisms.
Time: Tue 10/6 3:30 pm
Speaker: Dr. Paul Armsworth, UTK EEB
Topic:Optimal Spatial Management of Marine Fisheries - A Case Study Example
Abstract: Technological advances and improvements in our understanding of the life history of marine species make increasingly precise spatial management possible in many fisheries. Spatial management strategies are often recommended as ways to manage bycatch in fisheries and fisheries that threaten particularly sensitive life history stages, like spawning. We examine a case study that illustrates when such management measures can be justified on ecological and economic grounds. Specifically, we examine whether these measures present an economically efficient means to protect Atlantic bluefin tuna (Thunnus thynnus) on their western Atlantic spawning ground. Longline fishermen targeting yellowfin tuna (T. albacares) catch spawning bluefin as bycatch in the Gulf of Mexico, an area where bluefin are supposed to be protected. We combine a behavioral model of bluefin migration with population dynamic models for the two species and an economic representation of relevant fisheries. Time-area closures are predicted to be economically costly if there is little scope for recovery of the bluefin stock. However, such closures can be economically efficient if integrated into long-term management plans to rebuild the bluefin population. This difference reflects changes to the relative profitability of the fisheries involved. Whether a closure is optimal depends on the productivity of a rebuilt bluefin population, the discount rate, and the costs of forgone fishing opportunities.
Time: Tue 10/20 3:30 pm
Speaker: Dr. Celine Devaux, Imperial College, UK
Topic:Evolution of Flowering Time and Reproductive Isolation
Abstract: This study investigates reproductive isolation in time within and among species, and changes in flowering phenologies. Quantitative genetic models of flowering time allow an examination of early and late stages of speciation, and predict changes in the population and individual flowering phenologies in different ecological scenarios. Application of these models to the sympatric speciation of palm trees on Lord Howe Island is then discussed.
Time: Tue 11/3 3:30 pm
Speaker: Dr. Brian O'Meara, UTK EEB
Topic:Joint species Inference and Species Delimitation
Abstract: Species delimitation and species tree inference are difficult problems in cases of recent divergence, especially when different loci have different histories. Here I quantify the difficulty of jointly finding the division of samples to species and estimating a species tree without constraining the possible assignments a priori. I introduce a parametric and a nonparametric method, including new heuristic search strategies, to do this delimitation and tree inference using individual gene trees as input. The new methods were evaluated using thousands of simulations and 4 empirical data sets. These analyses suggest that the new methods, especially the nonparametric one, may provide useful insights for systematists working at the species level with molecular data. However, they still often return incorrect results.
Time: Tue 11/17 3:30 pm
Speaker: Dr. Jaewook Joo, UTK Physics and Astronomy
Topic:TBA
Abstract: TBA
Time: Tue 12/8 3:30 pm
Speaker: Dr. William Godsoe, NIMBioS Postdoc
Topic:
Abstract: Some of the most important hypotheses in ecology are ideas about how species distributions change over space and time. Our theoretical understanding of species distributions is a rich amalgam of many ecological processes including dispersal, extinction, biotic interactions and abiotic environmental requirements. That said empiricists can usually only measure a fraction of these processes in any given system. Here I argue that this disconnect represents a major challenge for ecology and particularly for correlative models of species distributions. I then show that we can use probability theory to develop an intuitive understanding of the relationship between complex mathematical models and available empirical data. My results focus on interpreting climate models in the face of biotic interactions and inferring ecological divergence with presence data.
