Overall Summary

Our laboratory’s research is devoted to developing a robust framework for the science of coevolutionary biology. We are attempting to understand how the process of coevolution contributes to the organization of the earth’s biodiversity.

The coevolutionary process. Coevolution is reciprocal evolution between interacting species driven by natural selection. It is responsible for many of the major events in the history of life, and it is a major force in organizing the web of life. Coevolution shapes networks of interacting species at local levels, regional levels, and global levels. It weaves the threads of biodiversity into a rich and resilient fabric.

The geographic mosaic of coevolution. Coevolution, like all evolution, is a relentless process, creating ever-changing geographic mosaics in how species interact with one another. Local populations of one species often become adapted to local populations of other species. Even the same species of predators and prey, parasites and hosts, competitors, and mutualists interact and coevolve with each other in different ways in different ecosystems. The connections among local populations create a kaleidoscope of patterns of adaptation over larger geographic scales. At a time when ecosystems are changing quickly worldwide, it has become increasingly important for us to understand how environmental changes affect the evolution of interactions among species at local scales through global scales.

The rate of coevolutionary change. These evolutionary changes can occur quickly. Local coevolutionary changes can sometimes occur on time scales of only a few decades, indicating that there is often no real difference between ecological time and evolutionary time. The challenge is to understand how interactions can be so highly dynamic and yet sometimes persist for millions of years. If we can understand how persistence occurs in relatively unmodified ecosystems, then we will be in a much better position to manage the earth’s biodiversity in the increasingly human-dominated ecosystems worldwide.

How we study coevolution. In our research, we therefore work at multiple time scales and spatial scales, studying some traits and interactions that evolve rapidly and others that evolve more slowly. We study populations in relatively pristine environments, populations in highly modified environments, populations living in experimental microcosms where we observe evolution under highly controlled conditions, and mathematical models to help guide our questions and interpretations. We study a wide range of species, including microbes, plants, fungi, insects, and vertebrates, looking for common patterns and processes that shape the diversity of life.