Females are at a disadvan- tage compared to hermaphrodites because they do not contribute any genes to the next generation through pollen. To persist, they must have some compensating selective advantage. We hypothesize that the selective advantage of females is that they are obligately outcrossing, whereas hermaphrodites can self and their inbred progeny are less fit. I am also investigating adaptive radiation in Hawaiian Bidens . The 27 endemic taxa of Bidens on the Hawaiian Islands are extremely morphologically and ecologically diverse, yet all evolved from a single ancestral species which colonized from Central America.
All Hawaiian species are interfertile, and have diverged little in chemistry or isozymes.
Founder effects, and morphological adaptation to the diverse habitats of the Hawaiian Islands, appear to be the most important causes of adaptive radiation and the early stages of macroevolution. We are comparing Hawaiian Bidens with their continental relatives, and testing whether a secondary adaptive radiation of Bidens in southeastern Polynesia evolved from Hawaiian ancestors or South American ones. Our goal is a genetic analysis of speciation, adaptive radiation, and macroevolution. Selected Publications Ganders, F, Berbee, ML and Pirseyedi, M. 2000. Evidence for the Continental Relatives of Hawaiian and Marquesan Bidens.