Plants and animals are constantly evolving in response to other species with whom they interact, a process known as coevolution. An example is prey species, which are always evolving new or stronger mechanisms for escaping from predators, while predators are always evolving new or better ways to overcome their prey's evolving defenses. Although coevolution is a fundamental process in ecology and evolution, little is known about how it works and how it shapes species and ecological communities.
Tucker Gilman, a postdoctoral fellow at the National Institute for Mathematical and Biological Synthesis, is developing a modeling framework to explore the relationship between coevolution and speciation, the biological process by which new species arise. The goal of Gilman's research is to understand how coevolution shapes the interactions between species and the structure and composition of ecological communities.
"Most theoretical work has assumed that speciation occurs while other species in the environment remain unchanged. In nature, however, species often evolve strongly and rapidly in response to evolutionary change in the species with which they interact. When the strength or direction of interaction between such coevolving species varies in space, coevolution can generate different selective pressures within a species at different locations. This suggests that coevolution may sometimes favor speciation," Gilman said.
However, the conditions under which speciation can occur in coevolving populations have not been extensively explored.
Gilman's modeling framework will investigate these conditions in two cases. In the first case, the framework will explore evolution in the independent traits that govern the interaction rate between two species. In the second case, the variations across geographical space that affect the interaction rate between two species will be investigated.
Gilman, who has a Ph.D. in zoology from the University of Wisconsin, became interested in his current research after entering graduate school. His original plan was to do field studies to demonstrate the economic value of biodiversity, but while working in the ecological theory lab at the University of Wisconsin, Gilman was introduced to mathematical biology and the myriad ecological and evolutionary questions researchers can investigate with mathematical tools.
"One of the great things about my field of research is that every day really is different. Some days I concentrate on mathematics solutions or writing computer programs, other days I focus on reading about other scientists’ work or writing up my own research. The problems I work on are varied, and when one starts to get old it is time to move on to another. So, intellectually, it is really quite exciting," Gilman said.
Gilman hopes that the results of his research will help scientists understand the two-way relationship between evolutionary and ecological processes in speciation, and perhaps ultimately aid conservationists and ecosystem managers interested in maintaining biodiversity and in preserving the function of ecosystems.
The National Institute for Mathematical and Biological Synthesis (NIMBioS) brings together researchers from around the world to collaborate across disciplinary boundaries to investigate solutions to basic and applied problems in the life sciences. NIMBioS is supported by the National Science Foundation, the U.S. Department of Homeland Security, and the U.S. Department of Agriculture with additional support from The University of Tennessee, Knoxville.