Morphological and Phylogenetic Diversification of the Muroid Rodents

了解地球上生命的多样性是进化生物学的一个基本目标。为了解决这一基本问题，本研究将：(1)利用550个幕鼠类物种的DNA序列数据，建立幕鼠类啮齿动物(最多样化和最成功的哺乳动物群体)的进化树；(2)利用3D成像工具对这些物种的头骨进行解剖学研究；(3)将解剖学结果与系统发育学结果相结合，以确定不同谱系在何时何地根据物种的数量以及头骨和牙齿的变化而发生多样化。这些结果将决定哪些机制--适应、新地区的殖民或固有的“进化性”的变化--导致多样性增加。这项研究也将对生物医学科学具有广泛的实用价值，因为鼠类啮齿动物包括生物医学研究中使用的大多数物种(例如，小鼠、大鼠、仓鼠)。了解它们的进化史可以深刻地改变我们解释这些研究的方式。系统发育也将作为选择新物种进行生物医学研究的路线图。此外，研究小组将在DNA测序、形态分析和系统发育方面培训几名博士后研究人员、研究生、本科生和高中生。

Understanding how diversity of life on earth grows is a fundamental goal of evolutionary biology. To address this essential question, this research will: (1) build an evolutionary tree (phylogeny) for muroid rodents (the most diverse and successful group of mammals) using DNA sequence data from 550 muroid species, (2) conduct anatomical studies of the skulls of those species using 3D imaging tools, and (3) combine the anatomical results with the phylogenetic results to determine when and where different lineages diversify, in terms of numbers of species and modifications of the skull and dentition. The results will determine which mechanisms - adaptation, colonization of new areas, or changes in inherent "evolvability" - cause diversity to increase.This research will also have broad utility to the biomedical sciences because the muroid rodents include most of the species used in biomedical research (e.g., mouse, rat, hamster). Understanding their evolutionary history can profoundly change how we interpret those studies. The phylogeny will also serve as a road map for choosing new species for biomedical studies. In addition, the research team will train several post-doctoral researchers, graduate students, undergraduate students, and high school students in DNA sequencing, morphological analysis, and phylogenetics.