Doctoral Dissertation Improvement: Phylogenetic Relationships and Gene Flow Among Southern African Baboons

普通狒狒(Papio)包括一系列地理上截然不同的形式或半物种，虽然它们在外表和行为上彼此明显不同，但众所周知，它们在野外范围相交的地方进行杂交。PAPIO在研究影响密切相关的杂交物种进化的分歧和网状结构的过程中特别有用，因为狒狒是我们唯一拥有详细的行为、遗传和形态数据的灵长类动物，以及对杂交动态的长期研究。除此之外，对帕皮奥的研究可以提供对进化物种的更直接的洞察，比如早期人，它们占据着类似的经济区。像早期的人一样，狒狒是陆地上的生态通才灵长类动物，在非洲更新世的稀树草原和林地进化而来。这些环境中气候驱动的变化影响了帕皮奥的进化，很可能也影响了人。然而，狒狒保留了这些事件的时间和地理位置的遗传特征，而最近进化的现代人已经失去了这些特征。目前关于Papio进化的知识主要来自对东非狒狒的研究。然而，目前还不清楚这些东非狒狒是否代表了帕皮奥的整体形象。因此，这项研究将重点放在南部非洲类型之间的进化关系和基因流动模式上，这两种形式的黄色和chacma狒狒在赞比亚中部相互进行身体接触。这两种形式的种群之间的进化关系将从线粒体DNA序列数据中推断出来，而种群之间的遗传交换将使用线粒体DNA和一系列核基因组微卫星标记来识别。这项研究涉及的问题包括：南部非洲狒狒种群之间的关系是什么？这两种形式是杂交的吗？如果是这样的话，由此产生的基因流动采取什么模式？这种基因交换是否像东非那样是由雄性从其出生群体扩散到附近的其他群体所推动的？这些问题的答案将有助于澄清Papio的分类，提高我们对狒狒物种之间的关系以及影响它们进化的因素的理解，并为了解这些过程如何影响类似灵长类物种的进化提供洞察力。浣熊通常用于生物医学、行为和遗传学研究。对这些重要的模式生物之间的进化关系的准确理解对于这样的研究是必要的。该项目将为联合PI和本科生提供科学的培训机会。它还将促进美国和赞比亚科学家之间的专业联系和合作，而这并不是生物人类学家研究的传统地理重点。

Common baboons (Papio) comprise a series of geographically distinct forms or 'semi-species' that, while recognizably different from one another in appearance and behavior, are known to hybridize in the wild where their ranges meet. Papio is particularly useful in the study of the processes of divergence and reticulation that affect the evolution of closely-related, hybridizing species because baboons are the only primates for which we have detailed behavioral, genetic, and morphological data as well as long-term research in the dynamics of hybridization. In addition to this, studies of Papio can provide more direct insight into the evolution species, like early Homo, that occupy similar econiches. Baboons, like early Homo, are terrestrial, ecologically generalist primates that evolved in the savannas and woodlands of Pleistocene Africa. The climate-driven changes in these environments that affected the evolution of Papio may well have impacted Homo. However, baboons retain the genetic signature of the timing and geographic placement of these events that more recently evolved modern humans have lost.Current knowledge of the evolution of Papio largely comes from studies of eastern African baboons. However, it is unclear if these eastern African baboons are representative of Papio as a whole. This study, therefore, will focus on the evolutionary relationships and patterns of gene flow among southern African forms, the yellow and chacma baboons, which come into physical contact with one another in central Zambia. The evolutionary relationships among populations of these two forms will be inferred from mitochondrial DNA sequence data, while genetic exchange between populations will be discerned using both mitochondrial DNA and an array of nuclear genomic microsatellite markers. Questions addressed by this research include: what are the relationships among populations of southern African baboons? Do these two forms hybridize, and if so, what pattern does the resulting gene flow take? Is this genetic exchange driven by the dispersal of males from their natal groups into other nearby groups, as in eastern Africa? Answers to these questions will help clarify the taxonomy of Papio, improve our understanding of the relationships among baboon species and the factors that have affected their evolution, and provide insight into how such processes may impact the evolution of similar primate species.Baboons are commonly used in biomedical, behavioral, and genetic research. An accurate understanding of the evolutionary relationships among these important model organisms is necessary for such studies. This project will provide scientific training opportunities for the co-PI and undergraduate students. It will also promote professional contact and collaboration between scientists in the United States and Zambia, which has not been a traditional geographical focus of research by biological anthropologists.