Dissertation Research: Developmental Origins and Evolutionary Consequences of Modularity in a Complex Trait

生物学的一个主要目标是了解动物多样性是如何产生的。形态多样性通过物种间发育的变化来进化，这可能是由于负责生长的基因的差异，也可能是由于个体发育环境的差异。这个项目试图了解成长过程中的环境差异是如何在成年后产生适应性变化的。具体地说，这项研究考察了饮食变化对以昆虫为食的小型哺乳动物--地鼠的颌骨生长和多样性的影响。地鼠的颌骨结构已经被证明在不同的环境中是不同的，因此是一个测试环境差异如何导致生长变化的模型系统。通过用两种不同猎物硬度的饲料饲养兄弟姐妹地鼠，并测量不同组之间的颌骨生长、形态和功能的差异，将通过实验测试不同饮食引起的颌骨生长的变化。这项研究从概念和方法上结合了发育、形态进化、动物形态和功能等领域，以阐明物种内生长和发育的变化最终如何产生物种间的多样性，从而对理解环境变化对动物多样性的影响具有重要意义。在这项研究的过程中，几名本科生将接受高级现场和实验室技术培训。

A major goal of biology is to understand how animal diversity is generated. Morphological diversity evolves through changes in development among species which could be due to either differences in the genes responsible for growth or variation in the environment under which individuals develop. This project seeks to understand how differences in environment during growth generate adaptive changes in adult form. Specifically, this study examines the effect of variation in diet on jaw growth and diversification across species of shrews, small insect eating mammals. Jaw structure in shrews has been shown to differ across environments and is thus a model system to test how environmental differences can produce changes in growth. Changes in jaw growth resulting from differences in diet will be tested experimentally by raising sibling shrews on two diets differing in hardness of prey, and measuring differences in jaw growth, form, and function between the groups. This research conceptually and methodologically integrates fields of development, morphological evolution, and animal form and function to elucidate how changes in growth and development within a species ultimately generate diversity among species and thus has important implications for understanding the consequences of environmental change on animal diversity. During the course of this study, several undergraduate students will be trained in advanced field and laboratory techniques.