One of the joys of studying evolution is that it provides a general conceptual framework for studying a diversity subjects and organisms. I and my students have used evolutionary theory to study subjects as diverse as foraging behavior, altruism, and the nature of individual differences, on organisms as diverse as microbes, zooplankton, insects, birds, fish, and humans. I try to ask an important question first and then seek the most suitable organism for answering the question. I also employ a combination of theoretical models, laboratory experiments, and field research as needed. See the publications section for my books and a selection of downloadable PDF files of selected articles.
Multilevel selection theory
I am perhaps best known for my work on multilevel selection, in which the fundamental ingredients of evolution-variation, heritability, and fitness differences-can exist at all levels of the biological hierarchy, from genes to ecosystems. Darwin invoked group-level selection to explain the evolution of human morality and traits in non-human species that benefit the group at the expense of the individual. Multilevel selection was largely rejected in the 1960’s but has since been revived, with implications that extend the length and breadth of the biological and human sciences.
The Darwinian revolution is complete for the biological sciences but is still in progress for the study of our own species. Not only can subjects such as psychology and anthropology be studied from an evolutionary perspective, but also philosophy, economics, history, religion, art and literature.
The nature of individual differences
Natural selection can potentially explain differences between species, between local populations of the same species, and between individuals within a single population. Thinking of single populations as ecologically and behaviorally diverse, as opposed to inhabiting a “single niche”, is relatively new with many implications for ecology, evolution, and behavior. Anne Clark and I were among the first to draw attention to this important subject, which we have studied in the context of shyness and boldness, cooperation and exploitation, and trophic polymorphisms.