DISSERTATION RESEARCH: Evolution of seed-cracking beak morphology in Darwin's Finches and their relatives

进化生物学的一个基本挑战是理解产生生物多样性的机制。传统的多样性研究主要集中在比较遥远种群之间的特征，但这种方法对引起密切相关物种之间差异的机制知之甚少。加拉帕戈斯群岛上的达尔文雀由14个关系密切的物种组成，它们的喙形和大小已经进化得极其多样化。类似地，加勒比红腹红雀，一组独立进化的近亲物种，也显示出相似的喙的多样性水平。第二组提供了一个理想的机会来测试达尔文雀喙形多样性的基因工具箱是否与其他物种共享。研究人员将对这两种鸟类的自然种群进行基因表达分析，然后在实验室对鸡胚胎的喙发育进行实验。这个项目将1)确定哪些基因参与了产生达尔文地雀高度特定的吃种子的喙，2)调查相同的基因是否被用于不同的鸟类群体以适应相似的环境。这项研究的结果将有助于对胚胎学过程如何在物种内部和物种之间产生变异的一般理解。该项目的跨学科性质，结合了野外工作和进化背景下的发育遗传学，将涉及与生物学多个领域的科学家合作。这项工作涉及国际合作和培训，以及本科生在实地和实验室方法方面的参与和指导。

A fundamental challenge in evolutionary biology is to understand the mechanisms that generate biological diversity. Traditional studies of diversity have focused on comparing traits between distant groups but such an approach tells little about the mechanisms that cause the differences between closely related species. Darwin's Finches in the Galapagos Islands comprise a group of fourteen closely related species that has evolved extreme diversity of their beak shapes and sizes. Similarly, the Caribbean Bullfinches, an independently-evolved group of closely related species, display similar levels of beak variety. This second group provides an ideal opportunity to test whether the genetic tool kit that fueled the diversity of beak shapes in Darwin's Finches is shared with other species. The researchers will perform analyses of gene expression in natural populations of both groups of birds followed by experiments with beak development in chicken embryos in the laboratory. This project will 1) establish which genes are involved in generating the highly specific seed-eating beaks of Darwin's Ground Finches and 2) investigate whether the same genes are used in a different group of birds to adapt to similar environments. The results of this research will aid the general understanding of how embryological processes generate variation within and among species.The interdisciplinary nature of this project, combining fieldwork and developmental genetics in an evolutionary context, will involve collaborations with scientists from several fields of biology. The work involves international collaborations and training, plus the involvement and mentoring of undergraduates in field and laboratory methods.