Browsing by Author "Kondo, Beatrice"
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Item ANCESTRAL STATE RECONSTRUCTION OF MIGRATION: MULTISTATE ANALYSIS REVEALS RAPID CHANGES IN NEW WORLD ORIOLES (ICTERUS SPP.)(The American Ornithologists' Union, 2006-03-20) Kondo, Beatrice; Omland, Kevin E.During the past century, numerous theoretical articles explored the evolution of seasonal migration in birds; many of these focused on environmental or social conditions that may have led to the origin of migration. More recent work has focused not on the origin of migration, but on changes in migratory behavior that have occurred in modern species and their immediate ancestors. We used a novel approach, a multistate ancestral state reconstruction of migration, to examine patterns of migratory evolution in the New World orioles (Icterus spp.). Both the multistate and binary reconstructions indicated repeated gains in migration. However, the multistate method revealed details of how migration may be gained that the standard binary-state reconstructions would not have shown. Our maximum-likelihood reconstruction, using branch lengths based on a molecular phylogeny, suggested multiple instances of rapid gain of migration. Furthermore, we found that every migratory species’ migration type diff ered from that of its closest relatives. Surprisingly, no partially migratory species was closely related to a fully migratory species. These novel patt erns involving gain of migration demonstrate the utility of multistate ancestral reconstruction for examining changes in migratory behavior in closely related birds.Item Recent Speciation Between the Baltimore Oriole and The Black-backed Oriole(The American Ornithologists’ Union, 2004-04-09) Kondo, Beatrice; Baker, Jason M.; Omland, Kevin E.A recent phylogenetic survey of the New World orioles (genus Icterus; Omland et al. 1999) suggested that the Baltimore Oriole (I. galbula) and the Black-backed Oriole (I. abeillei) are sister taxa. That survey examined mitochondrial DNA (mtDNA) from a single representative of each species in the genus. Here, we examine mtDNA sequences from 15 Blackbacked and 20 Baltimore Orioles. The two species appear to be very recently diverged, with average sequence divergences for both cytochrome b (cyt b) and the control region indicating a probable late Pleistocene split. Despite this very recent divergence, there is one fixed base-pair difference between the species in cyt b and another in the control region, suggesting that one or both species have undergone a bottleneck during or since speciation. This molecular evidence of recent divergence suggests that male plumage differences between Black-backed and Baltimore Orioles evolved very rapidly.