Dissertation Research: A Molecular Phylogeny of the Icterina

这个项目的目标是重建可能是世界上最多样化的鸟类家族的进化史：黑鸟。黑鸟科，或黄雀亚科，包括北美常见的红翼黑鸟、草地云雀和金莺，以及许多原产于墨西哥和中南美洲的物种。黑鸟的体型从果园的小黄莺到巨大的黑鸟，从严格的一夫一妻制的悦耳黑鸟到高度一夫多妻制的墨西哥黑鸟，从北方金莺闪闪发光的橙色到山雀的天鹅绒黑色，都是黑鸟。我们的任务是比较不同物种的DNA，并重建该群体的系统发育或家谱。使用这棵树，我们将试图回答几个重要的问题：高度社会性的血统是否比孤独的血统进化得更快？人类姿势、大脑大小和手形态的惊人快速进化可能是由于社会群体中的个人学习了新的食物采集技术后，引发了对新适应的密集选择。这种类型的进化在鸟类中发生过吗？在一些黄鼠族中，雄性(主要)使用精心制作的表演、歌曲和鲜艳的颜色来争夺配偶和食物。这些“显眼的”族群是不是比颜色较暗、“较安静”的族群进化得更快？当突变引入一种新类型的歌曲或一种新的颜色用于获取或保护资源时，也许就会出现一个全新的物种。黄蜂亚科的分子系统学应该会对进化过程产生丰富的见解。

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.