Population genomic analyses reveal hybridization and marked differences in genetic structure and demographic history of Scurria limpet sister species with parapatric distributions across the southeastern pacific

The study of sister species that occur in parapatry around biogeographic transition zones can help understand the evolutionary processes that underlie the changes in species composition across biogeographic transition zones. The South Eastern Pacific (SEP) coast is a highly productive coastal system that exhibits a broad biogeographic transition zone around 30–35ºS. Here, we present a comparative genome-wide analysis of the sister species Scurria viridula and Scurria zebrina, that occur in parapatry and whose poleward and equatorward range edges intersect in the 30–35ºS SEP biogeographic transition zone. We sampled 118 specimens sourced from nine sites from Tocopilla (22ºS) to Chiloé (41ºS) including one site where both species overlap and analyzed over 8,000 biallelic single nucleotide polymorphisms. We found evidence of hybridization between these species in the contact zone and found significant but contrasting population structures for both species. Our results indicate that the gen...

对分布于生物地理过渡带周边呈邻域分布（parapatry）的姊妹物种（sister species）开展研究，有助于解析驱动生物地理过渡带内物种组成变化的演化过程。东太平洋东南部（South Eastern Pacific, SEP）海岸为高生产力海岸生态系统，在南纬30°–35°区域存在宽阔的生物地理过渡带。本研究针对呈邻域分布的姊妹物种Scurria viridula与Scurria zebrina开展全基因组比较分析，二者的极向与赤道向分布边界在南纬30°–35°的东太平洋东南部生物地理过渡带内交汇。我们从托科皮亚（22°S）至奇洛埃（41°S）的9个采样点采集了118号标本，其中包含一处两物种共存的采样位点，并对超过8000个双等位基因单核苷酸多态性（biallelic single nucleotide polymorphisms）位点进行了分析。我们在该接触带内检测到两物种间的杂交现象，并发现二者的种群结构存在显著且迥异的分化特征。我们的研究结果表明，其遗传……