My research program explores the evolution of behavioral diversity among vertebrates, with emphasis on studies of mammals. Specifically, by combining field studies of behavior, ecology, and demography with molecular genetic analyses of kinship and population structure, I seek to identify the causes and consequences of variation in mammalian social behavior. Although I am broadly interested in social behavior and sponsor students working on a variety of vertebrate taxa, my current research focuses on studies of subterranean rodents from Argentina and Chile. The objectives of this work are as follows:
1) To identify ecological causes of sociality. Using subterranean rodents as a model system, I am testing the generality of ecological hypotheses that have been proposed to explain group living among mammals. Currently, I am using a comparative approach to identify the factors favoring sociality in two genera of subterranean rodents: Ctenomys and Spalacopus. Because Ctenomys includes both solitary and social species, studies of this genus can be used to explore the reasons for behavioral divergence among closely related taxa. At the same time, comparisons between group-living Ctenomys and Spalacopus provide an important opportunity to identify factors favoring behavioral convergence across larger geographic and taxonomic distances.
2) To assess the genetic consequences of sociality. Despite compelling theoretical arguments that genetic structure is influenced by social behavior, few empirical studies have explicitly addressed the role of sociality in shaping patterns of genetic diversity. To explore this issue, I am using selectively neutral (microsatellite) and non-neutral (MHC) markers to characterize genetic variation in the subterranean rodent species that are the focus of my field studies of the ecology of sociality. By combining analyses of multiple genetic markers with detailed behavioral and demographic data, this work is generating exciting new insights into the effects of social behavior on patterns of genetic diversification in vertebrates.
Lacey, E.A. 2004. Sociality reduces individual direct fitness in a communally breeding rodent, the colonial tuco-tuco (Ctenomys sociabilis). Behavioral Ecology & Sociobiology, in press.
Lacey, E.A. and J. R. Wieczorek. 2003. The ecology of sociality in rodents: a ctenomyid perspective. Journal of Mammalogy 84:1198-1211.
Hambuch, T.M. and E.A. Lacey. 2002. Enhanced selection for MHC diversity in social tuco-tucos. Evolution 56:841-845.
Lacey, E.A. 2001. Microsatellite variation in solitary and social tuco-tucos: molecular properties and population dynamics. Heredity 86:628-637.