Dissertation Research: Effect of Evolutionary History on Reproductive Isolation

生物学家长期以来一直试图发现一个物种如何进化成两个物种，这一过程被称为物种形成。有些人认为，对不同环境的适应推动了新物种的进化，这被称为生态物种形成。其他人则认为物种形成涉及与环境适应无关的进化变化，这可以称为零物种形成。这项研究将使用长期隔离的果蝇实验室种群，其中一些显示出早期的物种形成。 这些种群的群体一直保持在相同的环境中，有些群体适应不同的生态制度。这是一个理想的系统测试零和生态形态。来自不同种群的配偶产生的后代被称为杂交种。不能产生可行的和可育的杂交种提供了两个种群之间的初始物种形成的措施。研究许多实验室种群之间的杂交，有些是生态分化的，有些不是，将定量测试两种物种形成机制，生态或零分别，是相对更重要的。除了它对进化生物学的基本重要性，这项研究也有农业意义，因为它将表明长期分离的植物品种和动物品种如何容易地杂交，以产生有用的新的农业库存。该项目还将为几名本科生提供参与科学研究的机会。

Biologists have long sought to discover how one species can evolve into two species, a process known as speciation. Some have argued that adaptation to different environments drives the evolution of new species, which is called ecological speciation. Others propose that speciation involves evolutionary change that is not related to environmental adaptation, which can be called null speciation This study will use long-isolated laboratory populations of the fruit fly, Drosophila melanogaster, some showing incipient speciation. Groups of these populations have been kept in identical environments, with some groups adapted to different ecological regimes. This is an ideal system for testing both null and ecological speciation. Mates that come from different populations produce offspring called hybrids. The inability to produce hybrids that are viable and fertile provides a measure of incipient speciation between two populations. Studying hybrids between many lab populations, some ecologically differentiated and some not, will test quantitatively which of the two speciation mechanisms, ecological or null respectively, is relatively more important.In addition to its fundamental importance for evolutionary biology, this research also has agricultural significance, because it will suggest how readily long-separated plant varieties and animal breeds can be hybridized to yield useful new agricultural stocks. The project will also provide opportunities for several undergraduate students to participate in scientific research.