Adaptive radiation is the evolution of many species with differing phenotypes from a single ancestral species. This study will determine the evolutionary relationships of four lineages of Hawaiian songbirds, including the famous adaptive radiation of Hawaiian honeycreepers. Because the Hawaiian avifauna has suffered a major, human-caused extinction, this research relies on ancient DNA analysis of museum specimens and fossil bones of extinct birds. The study will estimate rates of DNA sequence evolution, and identify patterns and causes of species divergence among the islands of the Hawaiian archipelago. Traditional morphological analyses will also be performed, allowing insights into the rates and patterns of morphological change during adaptive radiation.
Adaptive radiations are an important component of evolutionary biology and the Hawaiian honeycreeper radiation has been an omnipresent textbook example of this process. The rates of DNA sequence evolution that will be calculated by comparison of DNA divergence with the ages of the Hawaiian Islands will be of use to many studies of evolutionary history for which rates of DNA sequence evolution are unknown. The study will train students, including Hawaiian ones, in research methods. Results will be incorporated into a zoo exhibit and other educational materials to provide a colorful illustration of the consequences and timeframe of evolutionary events.
