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之间的发育变化而进化，这可能是由于负责生长的基因的差异或个体发育环境的变化。该项目旨在了解生长过程中环境的差异如何产生成人形式的适应性变化。具体来说，这项研究考察了饮食变化对颌骨生长的影响，以及鼩鼱（一种以昆虫为食的小型哺乳动物）物种的多样化。鼩鼱的下颌结构在不同的环境中有所不同，因此它是一个模型系统，可以测试环境差异如何产生生长变化。由饮食差异引起的下颌生长变化将通过饲养两种不同食物的鼩鼱兄弟来测试，这些食物的猎物硬度不同，并测量两组之间下颌生长、形状和功能的差异。该研究在概念和方法上整合了发育、形态进化和动物形态和功能等领域，阐明了物种内部生长和发育的变化如何最终产生物种之间的多样性，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，几名本科生将接受先进的现场和实验室技术的培训。

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.