Doctoral Dissertation Improvement Grant: Primate Interspecific Interactions

在人类和非人类灵长类动物的进化中，来自不同生物种群的个体之间的杂交(即杂交)的重要作用日益得到承认。然而，现代人和人属其他成员之间的杂交对进化的全面影响仍然不清楚，也存在很大争议。关于该属内遗传交换和杂交的实际水平的其他问题也仍然存在。不幸的是，这些事件的相对古老使得这些关于人类进化的更细微而又重要的细节比更新的进化事件更困难。研究已灭绝的非人类灵长类动物杂交的遗传学方面提供了一种应对这一挑战的方法，因为非人类灵长类动物是人类进化的重要类似物。这项研究建议使用两种新热带猴子的遗传数据作为杂交的人类学模型：过去和现在的杂交和遗传交换在塑造灵长类种群历史中扮演了什么角色？为了检验这个问题，将在两个绒猴杂交区以及非杂交种群中采集遗传物质，以推断杂交对两个物种基因组的进化影响。Jakchus和C.Penicillata是巴西近缘关系密切的小型灵长类动物，对于杂交的人类学研究来说是一个特别有信息量的系统，因为(1)在它们活动范围的某些部分，它们被认为是在类似于早期人类的种群条件下进行杂交；(2)它们基因组中与人类基因组中某些区域同源的保守部分可用于研究杂交的基因组效应；以及(3)它们在交配系统中表现出与人类相似的灵活性。此外，许多研究人员对绒猴感兴趣，因为它们拥有一套独特的生物学和社会特征，如双胞胎、合作繁殖和社会抑制雌性排卵。然而，目前灵长类文献中几乎没有关于绒猴进化史的细节。该项目的学术价值有三个方面：(1)该项目将提供灵长类杂交在时间和空间上的多背景视角；(2)该项目的结果将拓宽目前关于绒猴进化的知识；(3)该项目的发现将使研究人员能够制定和测试关于人类和其他非人类灵长类杂交的新假说。该项目对灵长类保护、国际合作和推广有更广泛的影响。该项目的数据将有助于对入侵的绒猴物种和高度濒危的灵长类物种的灵长类种群管理和保护的决策。拟议的工作创造了大量机会，通过与几位巴西灵长类动物学家的国际合作，交流和传播关于灵长类杂交的想法。该项目的外展工作旨在培训美国和巴西的本科生分子生物学。此外，该项目的结果将构成为美国K-12学生设计的科学探究课程的基础。最后，该项目是学位论文研究的一部分，将有助于培养一名女性博士生。

A significant role for hybridization (i.e. interbreeding) between individuals from different biological populations is increasingly being recognized in the evolution of human and non-human primates. However, the full evolutionary impact of hybridization between modern humans and other members of the genus Homo remains unclear and highly debatable. Other questions regarding actual levels of genetic exchange and interbreeding within this genus also remain. Unfortunately, the relative antiquity of such events makes these finer grain, yet important details regarding human evolution more difficult than more recent evolutionary events. Studying genetic aspects of hybridization in extinct, non-human primates provides one way to tackle this challenge because non-human primates serve as important analogs of human evolution. This study proposes to use genetic data from two Neotropical monkeys, common (Callithrix jacchus) and black-tufted marmosets (C. penicillata) as anthropological models of hybridization to address the following question: What is the role of past and present hybridization and genetic exchange in shaping primate population histories? To examine this question, genetic material will be sampled within two marmoset hybrid zones, as well from non-interbreeding populations to make inferences about the evolutionary effects of hybridization on the genomes of the both species. C. jacchus and C. penicillata are small, closely-related Brazilian primates that are an especially informative system for the anthropological study of hybridization because (1) in certain parts of their ranges, they are thought to be interbreeding under population conditions similar to that of early humans; (2) parts of their genomes that are conserved and homologous to certain regions within the human genome can be used to study genomic effects of interbreeding; and (3) they exhibit similar flexibility in mating systems as do humans. Additionally, marmosets are of interest to many researchers because they possess a unique suite of biological and social traits such as twinning, cooperative breeding and social suppression of ovulation in females. Yet, few details about the evolutionary history of marmosets are currently available in the primatological literature. The intellectual merits of this project are threefold: (1) this project will provide a multicontext view of primate hybridization in terms of time and space, (2) the project's results will broaden current knowledge about marmoset evolution, and (3) project findings will allow researchers to formulate and test new hypotheses about hybridization in human and other nonhuman primates. This project has broader impacts on primate conservation, international collaboration,and outreach. The data for this project will assist in decisions about primate populationmanagement and conservation for invasive marmoset species and highly endangered primates. The proposed work creates ample opportunities for the exchange and dissemination of ideas about primate hybridization through international collaboration with several Brazilian primatologists. Outreach efforts of this project are aimed to train both American and Brazilian undergraduate students in molecular biology. Additionally, the results of this project will form the basis of scientific inquiry lessons designed for American K-12 students. Finally, this project is part of dissertation research which will aid in the training of a female doctoral student.