This past Friday, Biology Professor Mark McPeek spoke on speciation, diversification, and his personal research at Dartmouth College. As a community ecologist, he studies how ecological processes shaped organismal adaptation and variation, and how they currently affect species abundance and distribution.
McPeek began by describing the relationship between ecology and evolution. “I can’t understand one without understanding the other.”
In his research, McPeek is determined to associate speciation and extinction in a realistic ecological context in order to find accurate depictions of the relationship between adaptations, ecology, and current species distributions.
McPeek focused largely on his years of studying damselflies. His research focuses on two different species, one in the genus Enallagma and the other in the genus Lestes. Both species live in lakes and ponds and have specialist populations that require different amounts of annual freshwater. The differing ecologies of these specialist populations have exposed the organisms to varying predators as well, tying together the ecological aspect of the population’s life with the food web of the disparate communities.
Damselfly variation has allowed McPeek to test a wide assortment of ecological effects on the species’ adaptations. In a trial to gain information on a damselfly’s attack response mechanism, McPeek found that the instinct to remain still—to avoid fast predators dependent on vision, like fish—versus the instinct to swim away—to avoid slower predators—played little to no part in the speciation of the damselfly.
McPeek has found, however, that Damselfly speciation is purely sexual, and does not involve ecological predator-prey relationships or possible disease resistance adaptations. McPeek’s experience has allowed him to better understand the connections between the diversity of species and the conditions of the surrounding environment. As he continues his research while teaching, he plans to continue combining the aspects of the biological world and to discover patterns in nature with an inclusive outlook.
McPeek concluded by summing up his goal as a scientist: “to see nature with a naturalists eye, and translate that vision into a theoretician’s perspective.”