DISSERTATION RESEARCH Fossils and phylogeny: investigating the timing of diversification in a diverse lineage of Neotropical rodents (Caviomorpha: Octodontoidea)

生物多样性模式是物种形成和灭绝等历史过程的产物，但活着的物种只保留了这一历史的一部分。拥有强大化石记录和多样化生态和生物地理辐射的谱系提供了更多的洞察力。这个项目的重点是一个这样的血统--奥特顿托伊德(迪格斯及其亲属)。这些啮齿动物种类繁多(6科193种)，遍布新热带地区，它们的化石记录可以追溯到渐新世(78个化石属)。这个项目将通过将化石及其地质年代的信息与现有物种的DNA序列相结合，来调查这些啮齿动物的模式、时间和多样化的速度。这些数据将被用来为群体的进化生成一个时间假说，然后将被用来检验历史和生态因素如何随着时间的推移影响进化速度。该项目为保护生物多样性提供了理论见解和实用信息，因为许多活着的章齿动物正受到威胁或濒临灭绝。在芝加哥菲尔德博物馆进行这项研究将有助于向国际观众推广；研究结果将显示在博物馆DNA发现中心的数字触摸屏上，并通过教育和会员部门的项目共享。除了为研究生提供关键培训外，这笔赠款还将为存储生物多样性和遗传数据的公共数据库做出贡献。

Biodiversity patterns are products of historical processes such as speciation and extinction, but living species preserve only part of this history. Lineages with robust fossil records and diverse ecological and biogeographic radiations offer greater insights. This project focuses on one such lineage, the Octodontoidea (degus and their relatives). These rodents are diverse (193 species across six families), found throughout the Neotropics, and their fossil record extends back to the Oligocene (78 fossil genera). This project will investigate the patterns, timing, and rates of diversification of these rodents by integrating information from fossils and their geologic ages with DNA sequences from living species. These data will be used to generate a temporal hypothesis for the group's evolution that will then be used to examine how historical and ecological factors have influenced evolutionary rates over time. This project offers theoretical insights and practical information for conserving biodiversity, as many living octodontoids are threatened or endangered. Conducting this research at Chicago's Field Museum will facilitate outreach to an international audience; results will appear on a digital touch-screen in the Museum's DNA Discovery Center and shared through programs in the Education and Membership departments. Besides providing key training to a graduate student, this grant will contribute to public databases where biodiversity and genetic data will be deposited.