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

进化生物学的一个根本挑战是理解产生生物多样性的机制。传统的多样性研究侧重于比较遥远种群之间的特征，但这种方法对导致近缘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类由14个密切相关的物种组成，它们的喙形状和大小进化出了极端的多样性。同样，加勒比海牛雀，一个独立进化的密切相关物种群体，表现出类似水平的喙多样性。这第二个群体提供了一个理想的机会来测试促进达尔文雀鸟喙形状多样性的遗传工具包是否与其他物种共享。研究人员将对这两组鸟类的自然种群中的基因表达进行分析，然后在实验室进行鸡胚胎喙发育的实验。该项目将1)确定哪些基因参与了达尔文地雀高度特异的食籽喙的生成；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过程如何在物种内和物种之间产生变异的一般理解。这个项目的跨学科性质，在进化的背景下结合了田野工作和发育遗传学，将涉及到与来自几个生物学领域的科学家的合作。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.