EARLS, K.D.: Skeletal diversity and morphology in Anseriformes: an explicitly phylogenetic analysis

Birds are very conservative in their overall morphology, and yet have diversified across a remarkable spectrum of locomotor behaviors. The associations of morphology with locomotor specializations have been murky, however, due to a lack of resolution within and among many avian clades. While it has been shown in other vertebrate groups that changes in bone shape and strength are often associated with locomotor transitions, this has not been clearly demonstrated for birds. To shed light on this problem, I have performed an explicitly phylogenetic analysis of bone morphology in the Anseriformes (ducks, geese) with two primary goals. First, I test the relationship between bone morphology, locomotor specialization, and phylogenetic history. Second, I evaluate the effects of competing phylogenetic hypotheses on the morphological analysis. This study is a first step toward understanding morphological changes which may have occurred early in the radiation of modern avian taxa.