Data from: Nesting habits influence population genetic structure of a bee living in anthropogenic disturbance

While most organisms are negatively affected by anthropogenic disturbance, a few species thrive in landscapes altered by humans. Typically, native bees are negatively impacted by anthropogenic environmental change, including habitat alteration and climate change. Here we investigate the population structure of the eastern carpenter bee Xylocopa virginica, a generalist pollinator with a broad geographic range spanning eastern North America. Eastern carpenter bees now nest almost exclusively in human made wooden structures, linking their geographic distribution and population structure to human activities and disturbance. To investigate the population structure of these bees, we sampled females from 16 different populations from across their range. Nine species-specific microsatellite loci showed that almost all populations are genetically distinct, but with high levels of genetic diversity and low levels of inbreeding overall. Broadly speaking, populations clustered into three distinct genetic groups: a Northern group, a Western group, and a Core group. The Northern group had low effective population sizes, decreased genetic variability and the highest levels of inbreeding in the dataset, suggesting that carpenter bees may be expanding their range northward. The Western group was genetically distinct, but lacked signals of a recent range expansion. Climatic data showed that summer and winter temperatures explained a significant amount of the genetic differentiation seen among populations, while precipitation did not. Our results indicate that X. virginica may be one of the rare “anthrophilic” species that thrive in the face of anthropogenic disturbance.

尽管多数生物会受到人为干扰的负面影响，但仍有少数物种能在人类改造的景观中蓬勃繁衍。通常来说，本土蜜蜂会受到包括生境改变与气候变化在内的人为环境变化的负面影响。本研究聚焦于东方木蜂（Xylocopa virginica）的种群结构，该物种为广食性传粉者，地理分布范围覆盖北美东部全境。如今东方木蜂几乎完全在人工木质结构中筑巢，使其地理分布与种群结构与人类活动及干扰紧密关联。
为解析该蜂的种群结构，研究人员从其分布范围内的16个不同种群中采集了雌性样本。通过对9个物种特异性微卫星位点（microsatellite loci）的分析发现，几乎所有种群均存在遗传分化，但整体遗传多样性水平较高，近交程度较低。总体而言，种群可划分为三个独立的遗传类群：北部类群、西部类群与核心类群。北部类群的有效种群规模较小、遗传变异水平降低，且为本数据集内亚近交程度最高的类群，提示东方木蜂可能正在向北扩张其分布范围。西部类群虽遗传分化显著，但未检测到近期分布扩张的信号。气候数据分析结果表明，夏季与冬季气温能够解释种群间大量的遗传分化，而降水则无显著关联。本研究结果显示，东方木蜂可能是少数能在人为干扰下蓬勃繁衍的嗜人物种（anthrophilic）之一。