Parallel Developmental Evolution of Shavenbaby in Drosophila

由于处于相似的生态条件下，不同的物种有时会进化出相似的外表和行为，这种现象被称为“趋同”。例如，有袋动物进化成各种类似胎盘动物的形式（例如，鼯鼠、食蚁兽、鼹鼠、老鼠和狼）。进化发育生物学（evo-devo）最近的研究表明，有时相似的基因可能是趋同的基础。在一个已经被详细研究过的例子中，一种果蝇，d.s hellia，已经进化出了几乎裸露的幼虫，而大多数果蝇的幼虫都有毛。另一种果蝇，D. virilis组，大约在6000万年前从D. sechellia中分化出来，也包含一些幼虫几乎裸露的物种。之前有证据表明，在这两种情况下，被称为剃须婴儿的同一基因导致了这些相似的几乎裸露的幼虫。这一假设将通过对D. virilis组剃须婴儿基因进化的详细分析进行严格检验。这项工作将涉及开发新的方法，将允许测试D. virilis的基因功能。这些关键的功能测试将提供令人信服的趋同分析，并将表明相同的基因如何在不同的物种中进化，从而导致相同的结果。这一信息将告诉我们相同基因进化导致趋同的频率。斯特恩博士的实验室在促进女性从事科学研究和培养本科生从事研究方面有着良好的记录。自从在普林斯顿建立这个实验室以来，大约有一半的研究生和博士后是女性。该实验室每年培养大约2-4名本科生，所有学生都进行独立研究，并在此基础上撰写论文。这些项目中大约有一半已经发表了论文，有几个学生继续攻读进化生物学的研究生。

Summary of Proposed ResearchDifferent species have sometimes evolved similar appearances and behaviors as a result of exposure to similar ecological conditions, a phenomenon called "convergence". For example, marsupials evolved into a variety of forms resembling placental animals (for example, flying squirrels, anteaters, moles, mice, and wolves). Recent work in evolutionary developmental biology, or evo-devo, indicates that sometimes similar genes may underlie convergence. In one example that has been studied in detail, one species of drosophilid fly, D. sechellia, has evolved nearly-naked larvae, whereas most drosophild flies have hairy larvae. A second group of drosophilids, the D. virilis group, which diverged from D. sechellia approximately 60 million years ago, also contains some species with nearly-naked larvae. Evidence was presented previously that the same gene, called shavenbaby, caused these similar nearly-naked larvae in both cases. This hypothesis will be rigorously tested by performing a detailed analysis of shavenbaby gene evolution in the D. virilis group. This work will involve developing new methods that will allow tests of gene function within D. virilis. These critical functional tests will provide a compelling analysis of convergence and will indicate how the same gene can evolve in different species to cause the same result. This information will inform how often the same genes evolve to cause convergence. Dr. Stern's laboratory has a strong record of promoting women in science and training undergraduates in research. Since starting the lab at Princeton approximately half of the graduate students and postdocs have been women. The laboratory trains approximately 2-4 undergraduates each year, all of whom perform independent research and write a thesis based on this work. About half of these projects have resulted in publications and several students have continued on to graduate school in evolutionary biology.