Title: Evolution, genetics and ecology of burrowing behavior in deer mice (genus Peromyscus)
Description: Behavioral differences among closely related species can result from adaptation via natural selection, and this is especially true of innately expressed behavior that shows evidence of complex design or function. A major goal of biologists is to understand how and why complex, adaptive behavior evolves. To this end, I investigated the evolution, ecology and genetics of innate burrowing differences in deer mice (genus Peromyscus). First, I show that several species of deer mice recapitulate their natural burrowing habits under laboratory conditions, even after many generations of captive breeding. When I compare these behaviors in the context of phylogeny, I find that burrowing is species&ndash;specific. I also find that the complex burrows of the oldfield mouse (P. polionotus), which have both a long entrance and an escape tunnel, likely arose from simple behavior similar to that expressed by two closely related species.