Species inhabiting marine environments face a wide range of environmental conditions that vary spatially across several orders of magnitude. The selective pressures that these conditions impose on marine organisms, in combination with potentially high rates of gene flow between distant populations, make it difficult to predict the extent to which these populations can locally adapt. Here, I identify how selection and gene flow influence the population genetic structure of the anemone Anthopleura elegantissima along the Pacific coast of North America. Isolation by distance is the dominant pattern across the range of this species, with a genetic break near Pt. Conception, CA. Furthermore, demographic modelling suggests that this species was historically confined to southerly latitudes before expanding northward. Outlier analyses identify 24 loci under selection (out of ~1,100), but the same analysis on simulated genetic data generated using the most likely demographic model erroneously identified the same number of loci under selection, if not more. Taken together, these results suggest that demographic processes are the dominant force shaping population genetic patterns in A. elegantissima along the Pacific coast of North America. I discuss these patterns in terms of the evolutionary history of A. elegantissima , the potential for local adaptation, and their consequences with respect to interactions with the endosymbiont Breviolum muscatinei across their geographic range.

中文翻译：

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海葵Anthopleura Elegantissima中的基因流动限制了广泛地理范围内的局部适应性特征。

居住在海洋环境中的物种面临着各种各样的环境条件，这些环境条件在空间上有几个数量级的变化。这些条件对海洋生物施加的选择性压力，再加上远距离种群之间潜在的高频率基因流动，使得难以预测这些种群可以局部适应的程度。在这里，我确定选择和基因流如何影响海葵Anthopleura Elegantissima的种群遗传结构。北美太平洋沿岸。通过距离隔离是该物种范围内的主要模式，Pt附近有遗传断裂。构想，CA。此外，人口统计学模型表明，该物种在向北扩展之前，一直局限于南纬。离群值分析可识别出24个被选择的基因座（约1,100个），但是对使用最可能的人口统计学模型生成的模拟遗传数据进行的相同分析错误地识别了相同数量的被选择基因座，甚至更多。两者合计，这些结果表明人口统计过程是塑造北美太平洋沿岸A. Elegantissima种群遗传模式的主导力量。我将根据人类进化史来讨论这些模式。A. Elegantissima，本地适应的潜力，以及它们与内共生麝香小球藻在其地理范围内相互作用的后果。