Speciation in Darwin's Finches

Princeton University, Princeton NJ

Investigators

Abstract

Speciation is the fundamental process in evolution that generates biological diversity. There is much debate on how it occurs and what the responsible mechanisms are. Most recent advances in understanding have come from genetic analyses of closely related species in the laboratory. Less is known from studies in nature about the ecological circumstances and microevolutionary forces responsible for speciation. The proposed research takes advantage of an exceptionally favorable situation provided by Darwin's Finches on the Galapagos islands. They are an intact group living in a largely undisturbed environment. Four species have been intensively studied on the small island of Daphne Major for 30 years. Building on this, populations at different stages in the speciation process will be investigated by a combination of methods; direct observations of individually marked birds to determine breeding patterns and survival, and responses to experimental playback of tape-recorded songs to determine behavioral limits to species recognition. Results of this research will help to clarify the mechanisms of speciation under natural circumstances. There are two broader impacts. First, the research will elucidate factors that influence and maintain genetic variation in small and potentially endangered populations in need of conservation. Second, results of the long-term study will serve an educational function in the media.