Barr Kelly, Beichman Annabel C, Kalhori Pooneh, Rajbhandary Jasmine, Bay Rachael A, Ruegg Kristen, Smith Thomas B
Center for Tropical Research Institute of the Environment and Sustainability University of California, Los Angeles Los Angeles CA USA.
Department of Ecology and Evolutionary Biology University of California, Los Angeles Los Angeles CA USA.
Evol Appl. 2020 Oct 31;14(3):674-684. doi: 10.1111/eva.13147. eCollection 2021 Mar.
Habitat loss and alteration has driven many species into decline, often to the point of requiring protection and intervention to avert extinction. Genomic data provide the opportunity to inform conservation and recovery efforts with details about vital evolutionary processes with a resolution far beyond that of traditional genetic approaches. The tricolored blackbird () has suffered severe losses during the previous century largely due to anthropogenic impacts on their habitat. Using a dataset composed of a whole genome paired with reduced representation libraries (RAD-Seq) from samples collected across the species' range, we find evidence for panmixia using multiple methods, including PCA (no geographic clustering), admixture analyses (ADMIXTURE and TESS conclude K = 1), and comparisons of genetic differentiation (average FST = 0.029). Demographic modeling approaches recovered an ancient decline that had a strong impact on genetic diversity but did not detect any effect from the known recent decline. We also did not detect any evidence for selection, and hence adaptive variation, at any site, either geographic or genomic. These results indicate that species continues to have high vagility across its range despite population decline and habitat loss and should be managed as a single unit.
栖息地丧失和改变已导致许多物种数量减少，常常达到需要保护和干预以避免灭绝的程度。基因组数据提供了机会，能够以远超传统遗传方法的分辨率，用有关重要进化过程的详细信息为保护和恢复工作提供依据。在上个世纪，三色黑鹂（）数量锐减，主要是由于人类活动对其栖息地的影响。利用一个由全基因组与来自该物种分布范围内所采集样本的简化基因组文库（RAD-Seq）组成的数据集，我们通过多种方法找到了随机交配的证据，这些方法包括主成分分析（无地理聚类）、混合分析（ADMIXTURE和TESS得出K = 1）以及遗传分化比较（平均FST = 0.029）。种群统计学建模方法发现了一次对遗传多样性有强烈影响的古代种群数量下降，但未检测到已知近期种群数量下降所产生的任何影响。我们也未在任何地理或基因组位点检测到选择以及适应性变异的证据。这些结果表明，尽管种群数量下降且栖息地丧失，但该物种在其分布范围内仍具有较高的迁移性，应作为一个单一单元进行管理。
