Dissertation Research: A Comparative Analysis of Two Orthopteran Hybrid Zones

点击翻译按钮获取中文摘要

9321453 Futuyma Hybrid zones are areas in which two genetically distinct groups (e.g., "species") successfully reproduce with each other to at least a limited extent. The study of hybrid zones allows us to learn about the mechanisms of reproductive isolation and their evolution, an understanding of which is critical to our understanding of speciation. According to the most widely accepted species definition, two groups of organisms that are not interfertile belong to two different species. Hybrid zones represent an intermediate stage of speciation, with limited gene flow between the "species": the two groups are neither completely interfertile nor completely reproductively isolated. This intermediate situation provides a unique opportunity for biologists to apply analytical techniques developed for the study of single species population--techniques that cannot be used in the total absence of gene flow--to improve our understanding of how new species develop. This study will take the nearly unique approach of comparing two geographically well separated hybrid zones involving the same two " species". Patterns of variation in behavior, morphology, proteins, DNA, and chromosomes will be compared across the hybrid zones. By combining this information with information about the differing ecology and history of contact between the two "species" in each zone, this research will improve understanding of how ecology and history may influence patterns of interactions between incompletely isolated taxa. The research will also produce insight into the circumstances under which hybridizing groups may evolve into reproduc tively isolated species. In addition to such inferences that may emerge from this study (which would then require testing in other contact zones), the basic information gathered to describe the hybrid zones will permit detailed studies addressing a variety of questions in the future, as well as the tracking of the two zones through time. U W U E G I K M O Q S U W ! ! ! F W W ( Times New Roman Symbol & Arial j j j j " h # EL* eL* e u # 7 Crystal Blackshear Crystal Blackshear