Dissertation Research: A Molecular Phylogeny of the Icterina

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The goal of this project is to reconstruct the evolutionary history of what may be the world's most diverse family of birds: the blackbirds. The blackbird family, or Icterinae, includes the familiar red-winged blackbirds, meadowlarks, and orioles of North America, as well as many species native to Mexico and Central and South America. The blackbirds range in size from the tiny orchard oriole to the gigantic Montezuma oropendula, in mating systems from the strictly monogamous melodious blackbird to the highly polygynous Mexican cacique, and in color from the radiant orange of northern orioles to the velvet black of mountain grackles. Our task is to compare the DNA of different species and reconstruct the group's phylogeny, or family tree. Using this tree, we will try to answer several important questions: Have the highly social lineages evolved more rapidly than the solitary ones? The astonishingly rapid evolution of human posture, brain size, and hand morphology may have resulted from intense selection for novel adaptations triggered when individuals in social groups learned new food-gathering techniques. Has this type of evolution occurred in birds? In some Icterine lineages males (primarily) use elaborate displays and songs and bright coloration to compete for mates and food. Have these "conspicuous" groups speciated more rapidly than the more dully-colored, "quieter" lineages? Perhaps an entirely new species could arise when a mutation introduced a novel type of song or patch of color to use in acquiring or defending resources. A molecular phylogeny of the Icterinae should produce a wealth of insights into the evolutionary process.