DISSERTATION RESEARCH: Linking population genetic patterns of introgressive hybridization to the breakdown of reproductive barriers in Darters (Percidae)

生物多样性取决于维持和消除物种间生殖隔离障碍的相互作用。然而，在物种的地理范围内，生殖障碍的完整性可能并不统一，导致物种之间的杂交和遗传交换的马赛克。在美国东南部彩虹飞镖(Etheostoma Caeruleum)和橘飞镖(E.spectabile)重叠的地理范围内，出现了杂交的马赛克图案。这个项目将利用这些较短的物种内部和之间的实验杂交，研究杂交后代的形成和对它们不利的选择压力，并将确定交配后障碍的强度和对称性的地理模式。杂交可能是对濒危物种的严重威胁，但人类介导的干扰和生殖障碍的破坏之间的关系尚不清楚。在大约230种飞镖中，近三分之一被认为是脆弱、受威胁或濒危的，这项研究将为这些物种和其他物种的保护和管理提供信息。该项目还为本科生提供人口遗传学、生殖生物学、博物馆技术和实地研究方面的培训，并向博物馆藏品和公共数据库提供标本和数据。

Biodiversity depends on the interplay of maintenance and dissolution of reproductive isolating barriers between species. However, the completeness of reproductive barriers may not be uniform across a species' geographic range, resulting in a mosaic of hybridization and genetic exchange between species. A mosaic pattern of hybridization appears within the overlapping geographic ranges of Rainbow Darters (Etheostoma caeruleum) and Orangethroat darters (E. spectabile) in the southeastern United States. This project will investigate the formation of hybrids and the selection pressures that act against them, using experimental crosses within and between these darter species, and will determine geographic patterns in the strength and symmetry of post-mating barriers. Hybridization can be a serious threat to endangered species, but the relationship between human-mediated disturbance and breakdown of reproductive barriers is not understood. Nearly one third of the approximately 230 species of darters are considered vulnerable, threatened, or endangered, and this research will inform conservation and management of these and other species. This project also provides training in population genetics, reproductive biology, museum techniques, and field-based research to undergraduate students and contributes specimen and data to museum collections and public data bases.