Leading evolutionary biologist DAVID C. QUELLER is the Spencer T. Olin Professor of Biology at Washington University in St. Louis. He received his BA from The University of Illinois in 1976, and his PhD from The University Michigan in 1982. He was on the faculty of Rice University in Houston, Texas from 1989 till 2011, and was Harry C. and Olga K. Wiess Professor in Natural Sciences in the Department of Ecology and Evolutionary Biology. His work focuses on both theoretical and empirical aspects of the evolution of social interactions, including both sexual selection and kin selection. Recent theoretical studies have focused on generalizing inclusive fitness theory, the role of relatedness in viscous populations, and the importance of demographic advantages in the evolution of sociality in insects. He has also developed methods for estimating genetic relatedness using genetic markers and this work led to an extensive collaboration with Joan E. Strassmann on the importance of genetic relatedness in the evolution of social insects. They use DNA microsatellite markers to study altruism and conflict in both social insects and cellular slime molds.