DISSERTATION RESEARCH: Mechanisms Underlying Incipient Speciation in Peripheral Populations

南加州大学的苏珊娜·艾德曼兹博士和丹尼斯·彼得森先生正在研究桡足类动物加州虎足虫的早期物种形成。 我们对物种形成遗传学的了解大多来自少数模式生物（主要是果蝇），主要集中在性染色体上。 T. California提供了一种不具有形态学上可区分的性染色体的替代模型。 工作将侧重于物种范围南端的种群，那里的生殖隔离模式比物种范围其他部分更为严重，而且在质量上也有所不同。 该项目有三个主要目标：1）描述南方种群的生殖相容性模式，2）使用分子遗传学重建生殖不相容性的进化历史，3）使用分子标记来确定导致第一代和第二代杂交后代存活率降低的基因组区域。这项研究将通过研究生和本科生的职业发展和科学培训产生更广泛的影响。 它将有助于我们理解物种形成的过程，可以说是生物学中最重要但最不了解的问题之一。 此外，它侧重于遗传分化和生殖相容性之间的关系，一个相当重要的保护和管理的主题。

Dr. Suzanne Edmands and Mr. Dennis Peterson of the University of Southern California are studying the early stages of speciation in the copepod Tigriopus californicus. Much of what we know of the genetics of speciation comes from a handful of model organisms (chiefly Drosophila) and focuses largely on sex chromosomes. T. californicus provides an alternative model that does not have morphologically distinguishable sex chromosomes. Work will focus on populations at the southern end of the species range where patterns of reproductive isolation are more severe and qualitatively different than those found in the rest of the species range. The project has three primary goals: 1) describe patterns of reproductive compatibility in southern populations, 2) use molecular phylogenies to reconstruct the evolutionary history of reproductive incompatibility, and 3) use molecular markers to determine regions of the genome contributing to reduced survival in first- and second-generation hybrids. This research will have broader impacts through the career development and scientific training of both graduate and undergraduate students. It will contribute to our understanding of the process of speciation, arguably one of the most important yet least understood issues in biology. In addition, it focuses on the relationship between genetic divergence and reproductive compatibility, a subject of considerable importance to conservation and management.