Dissertation Research: Gene Flow and Mitochondrial DNA Evolution in a Cooperatively Breeding Songbird, the Grey- crowned Babbler (Pomatostomus temporalis)

斯科特·V·爱德华兹，在艾伦·C。威尔逊在 生物化学系和詹姆斯L。巴顿在博物馆 脊椎动物学，综合生物学系，将 采用新的分子技术来研究模式和原因， 社会鸣禽的地理变异。 该物种是 灰冠穗鹛（Pomatostomus temporalis） 在澳大利亚的北方和 新几内亚南部 它以其引人注目的社交活动而闻名。 所谓的“合作育种”系统，其中几个，往往 相关的，个人放弃自己的繁殖，以协助 主要繁殖对筑巢，守卫领土， 养育年轻人 进化生物学家一直对 这样的系统，因为它们可能导致遗传差异， 由于种群内的近亲繁殖， 另一方面，种群之间的地理差异可能 更多地是由于外在因素，如地形或 环境屏障，用于将人群与一个 另 每种情况都预测了不同的遗传模式， 多样性和家庭群体，人口， 区域层面。 最近发明的聚合酶链反应（PCR） 提供了一种方法，通过该方法可以 从大量的个体中简单快速地获得 一个物种 爱德华兹将从巴布勒身上采集血液样本 在其整个范围内的人口，其目标是获得 家庭、人口中有足够数量的个人， 地理区域。 基因研究将集中在一个 母系遗传分子的极端可变区 存在于所有高等生物的线粒体中 DNA. 当应用于该区域时，PCR将突出显示 家系内个体间的遗传差异 群体以及地理群体，并将提供一个 社会和/或历史的贡献 决定灰冠穗鹛遗传结构的因素。

Scott V. Edwards, working under Allan C. Wilson in the Department of Biochemistry and James L. Patton in the Museum of Vertebrate Zoology, Department of Integrative Biology, will employ new molecular techniques to study patterns and causes of geographic variation in a social songbird. The species to be studied, the Grey-crowned Babbler (Pomatostomus temporalis), is found throughout the northern portions of Australia and in southern New Guinea. It is well known for its conspicuous social system called "cooperative breeding" in which several, often related, individuals forsake breeding on their own to assist the main breeding pair in building nests, guarding territories and raising young. Evolutionary biologists have been intrigued by such systems because they may result in genetic differences between local populations due to inbreeding within populations; on the other hand, geographic differences among populations may be due more to extrinsic factors such as topographic or environmental barriers that serve to isolate populations from one another. Each scenario predicts different patterns of genetic diversity and relatedness at the family-group, population, and regional levels. The recently devised polymerase chain reaction (PCR) provides a method whereby high resolution genetic data can be obtained simply and rapidly from large numbers of individuals of a species. Edwards will collect blood samples from babbler populations throughout its range with the goal of obtaining adequate numbers of individuals within families, populations, and biogeographic regions. The genetic research will focus on an extremely variable region of a maternally inherited molecule found in the mitochondria of all higher organisms--mitochondrial DNA. The PCR when applied to this region will highlight the genetic differences among individuals within an among family groups as well as geographic populations, and will provide a means whereby the contribution of social and/or historical factors determine genetic structure in the Grey-crowned Babbler.