DISSERTATION RESEARCH: Effects of environmental stress on multiple generations of interpopulation hybridization.

众所周知，种群间杂种可以在第一代经历增强的适应度，然后在第二代经历降低的适应度。一些证据表明，杂种的适应性问题可以在后代中得到修复，而且杂种在环境压力下可能更受欢迎。本研究使用潮间带桡足类Tigriopus californicus评估杂交多代在良性和应激条件下（高盐度）。实验杂交种群将保持长达17个月，并每两代分析遗传，形态和健身组件。虎斑蝶的世代时间短、易于饲养和丰富的种群特异性分子标记使其成为这类实验的一个特别容易处理的系统。结果将检验杂交可以产生在环境胁迫下有利的遗传变异的特定假设，并将有助于阐明杂交在新物种形成中的作用。这项工作也直接关系到目前对入侵物种与本地种群混合或养殖生物与野生种群混合的影响的担忧。使用Tigriopus模型系统允许以严格的方式评估良性与压力条件的影响，这对于大多数关注物种来说是难以实现的。 此外，该项目还支持在一所服务于广泛而多样化的城市地区的大学进行本科研究和培训的机会。

It is well established that interpopulation hybrids can experience enhanced fitness in the first generation, followed by depressed fitness in the second generation. Some evidence suggests hybrid fitness problems can be repaired in later generations, and that hybrids may be favored under environmental stress. This study uses the intertidal copepod Tigriopus californicus to assess hybridization over multiple generations in both benign and stressful conditions (high salinity). Experimental hybrid populations will be maintained for up to 17 months and assayed for genetic, morphometric and fitness components every two generations. Tigriopus' short generation time, ease of husbandry and abundance of population-specific molecular markers make it a particularly tractable system for this type of experiment.Results will test the specific hypothesis that hybridization can create genetic variants that are favored under environmental stress, and will help to elucidate the role of hybridization in the formation of new species. This work is also directly relevant to current concerns about the impacts of invasive species mixing with native populations, or farmed organisms mixing with wild populations. Using the Tigriopus model system allows the effects of benign vs. stressful conditions to be assessed in a rigorous fashion that would be difficult to achieve for most species of concern. Additionally, this project supports opportunities for undergraduate research and training at a university that serves a broad and diverse urban area.