Doctoral Dissertation Improvement Grant: Primate Interspecific Interactions

在人类和非人类灵长类动物的进化过程中，来自不同生物种群的个体之间的杂交（即杂交）发挥着重要作用。然而，现代人与人属其他成员之间的杂交对进化的全面影响仍然不清楚，而且极具争议性。其他有关实际水平的遗传交换和杂交的问题也仍然存在。不幸的是，这些事件相对古老，使得这些关于人类进化的更精细但重要的细节比最近的进化事件更加困难。研究已灭绝的非人类灵长类动物的杂交遗传方面提供了一种解决这一挑战的方法，因为非人类灵长类动物是人类进化的重要类似物。本研究提出使用两种新热带猴的遗传数据，普通猴（Callithrix jacchus）和黑绒狨猴（C. penicillata）作为杂交的人类学模型来解决以下问题：过去和现在的杂交和遗传交换在塑造灵长类种群历史中的作用是什么？为了研究这个问题，将在两个狨猴杂交区以及非杂交种群中取样遗传物质，以推断杂交对两个物种基因组的进化影响。C. jacchus和C. penicillata是巴西的小型近亲灵长类动物，它们是人类学杂交研究的一个特别有用的信息系统，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的；(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；(3)它们在交配系统中表现出与人类相似的灵活性。此外，许多研究人员对狨猴很感兴趣，因为它们具有一系列独特的生物学和社会特征，如双胞胎、合作繁殖和雌性排卵的社会抑制。然而，关于狨猴进化史的细节目前在灵长类动物文献中是可用的。这个项目的智力价值有三个方面：(1)这个项目将从时间和空间的角度提供灵长类动物杂交的多背景观点；(2)这个项目的结果将拓宽目前关于狨猴进化的知识；(3)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动物杂交的新假设。该项目对灵长类动物保护、国际合作和推广具有更广泛的影响。该项目的数据将有助于灵长类动物种群管理和保护的决策，包括入侵的狨猴和高度濒危的灵长类动物。通过与几位巴西灵长类动物学家的国际合作，这项拟议的工作为交流和传播灵长类动物杂交的思想创造了充分的机会。该项目的推广工作旨在培养美国和巴西的分子生物学本科生。此外，该项目的结果将成为美国K-12学生科学探究课程设计的基础。最后，这个项目是论文研究的一部分，将有助于培养一名女博士生。

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.