DISSERTATION RESEARCH: A genomic and experimental characterization of local adaptation

大自然在非生物和生物因素中都提供了一系列的变化。这通常会导致一个物种的种群根据当地条件进化出一些特征，这些特征在该原生栖息地对个体有利，而在其他栖息地则不然。了解驱动这种局部适应的过程对于预测物种在面对快速环境变化时的命运至关重要。随着气温的升高，许多物种正在转移它们的活动范围，向极地或更高海拔地区移动，但海洋物种也面临海洋酸化的风险——由于从大气中吸收二氧化碳，海洋pH值持续下降。对于海洋双壳类动物来说尤其如此，它们需要特定的碳酸盐化学来形成外壳。北美西海岸的海洋pH值和温度具有自然的长期变化；因此，一些广泛分布的物种种群可能包含在低pH值和较高温度地区进化的适应性。这可以帮助科学家了解在快速的气候变暖事件中，物种基因组的哪些部分可能处于选择状态，或者突出基因组中适应这些条件的区域。这项研究为研究生提供培训，并为商业、政府、非政府组织和公共利益相关者提供额外的服务。提出的研究将测试是否适应环境变化发生在奥林匹亚牡蛎（Ostrea lurida）。这种在生态和商业上都很重要的双壳类动物零星地分布在加利福尼亚南部到加拿大中部海岸。利用种群基因组分析和普通花园实验，拟议的研究将测试来自加利福尼亚州旧金山湾、俄勒冈州库斯湾、华盛顿州普吉特湾和不列颠哥伦比亚省温哥华岛的不同种群之间的适应性差异。野生牡蛎的后代将在普通条件下饲养，并研究其生长速度、存活率和对温度和ph诱导应激的反应的差异。转录组学将用于表征基因表达的隐性变异，并识别与适应这些应激源有关的基因。

Nature provides a mosaic of variability in both abiotic and biotic factors. This often results in populations of a species evolving traits in response to local conditions that give an advantage to individuals in that native habitat but not in other habitats. Understanding the processes that drive such local adaptation is crucial to predicting the fate of species in the face of rapid environmental change. Many species are shifting their ranges to move poleward or to higher altitude sites as temperatures increase, but marine species are also at risk from ocean acidification - the ongoing decrease in ocean pH due to the uptake of carbon dioxide from the atmosphere. This is especially true for marine bivalves, who require specific carbonate chemistry to form their shells. The west coast of North America has natural long-standing variation in ocean pH and temperature; therefore, it is possible that some populations of wide-spread species could contain adaptations that have evolved in areas with low pH and higher temperatures. This may provide insight to scientists on what portions of the genome may be under selection in species during rapid climate warming events or highlight areas of the genome that have adapted to those conditions. The research provides training to a graduate student and additional outreach to commercial, government, non-governmental organizations, and public stakeholders. The proposed research will test whether adaptation to environmental variability has occurred in the Olympia oyster (Ostrea lurida). This ecologically and commercially important bivalve is patchily distributed from southern California up to the central coast of Canada. Using population genomic analyses and common garden experiments, the proposed research will test for adaptive differences among distinct and separate populations from San Francisco Bay, CA, Coos Bay, OR, Puget Sound, WA, and Vancouver Island, British Columbia. Offspring of wild oysters will be raised under common conditions and studied for differences in growth rate, survival, and response to induced stress from temperature and pH. Transcriptomics will be used to characterize cryptic variation in gene expression and identify genes involved in adaptation to theses stressors.