On June 12, 2007, PED Seminar Series Presents

Evolution of Altruism Theory: Fitness Accounting Methods and Causal Explanations

by Dr. Jeffrey Fletcher

For several decades the mechanisms by which altruistic and cooperative behaviors evolve have been vigorously debated. The main theories are kin selection (or inclusive fitness) theory, reciprocal altruism theory (including variations based on reputation, sanctions, and spatial structure), and multilevel (or group selection) theory. This debate has recently intensified in the literature with publications emphasizing the role of group selection in the evolution of eusociality and several articles in the last year that claim kin selection (genetic similarity between altruists and recipients) is the only mechanism that can account for biological altruism. My work has focused on unifying different theories of how altruism evolves and my talk will consider this recent controversy and its history from this perspective, including how these theories vary in their definitions of altruism and differences in the way they keep track of fitness consequences.

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