Dissertation Research: Experimental Test of Ecological Speciation in a Freshwater Minnow (Cyprinidae: Lavinia).

研究人员将确定生态和遗传因素在加州两个密切相关的淡水鱼物种(Lavinia symmetricus和L.exilicauda)之间繁殖隔离方面的影响程度。这两个物种一起出现在两个独立的流域：清湖和蒙特利湾河流。这两个物种之间的生殖隔离水平在两个排水系统中不同，广泛的杂交只发生在其中一个排水系统中。研究人员将在实验室中制作这两个物种之间的杂交，以衡量杂交后代与纯杂交后代的表现。允许形成新物种的过程一直是生物学的中心焦点。可以对最近被隔离的快速辐射物种中的个体群体进行分析，以确定哪些因素导致了生殖隔离。其他研究表明，有两种类型的过程导致快速辐射：生态和遗传。许多关于密切相关物种辐射的经验研究都集中在生态因素上。最近的研究表明，亲缘关系密切的物种之间的遗传不亲和性可能比人们认为的更普遍。这项研究的结果将使人们更好地了解促进物种形成和多样化的过程。

Bernardi0104832The investigators will determine the extent that ecological and genetic factors play on the reproductive isolation between two closely related freshwater fish species in California (Lavinia symmetricus and L. exilicauda). The two species occur together in two separate drainages: Clear Lake and Monterey Bay rivers. Levels of reproductive isolation between the two species differ in the two drainages with extensive hybridization occurring in only one of the drainages. The investigators will produce crosses between the two species in the laboratory to measure performance of the hybrids against the pure crosses. Processes that allow the formation of new species have been a central focus in biology. Groups of individuals in a rapidly radiating species that have recently become isolated can be analyzed to determine which factors are contributing to reproductive isolation. Other research has shown that there are two types of processes contributing to rapid radiations: ecological and genetic. Much of the empirical research on radiations in closely related species has focused on ecological factors. Recent work has revealed that genetic incompatibilities between closely related species may be more prevalent than believed. Results from this study will allow a greater understanding of the processes that promote speciation and diversification.