Data from: Partial genomic survival of cave bears in living brown bears

Although many large mammal species went extinct at the end of the Pleistocene epoch, their DNA may persist due to past episodes of interspecies admixture. However, direct empirical evidence of the persistence of ancient alleles remains scarce. Here, we present multifold coverage genomic data from four Late Pleistocene cave bears (Ursus spelaeus complex) and show that cave bears hybridized with brown bears (Ursus arctos) during the Pleistocene. We develop an approach to assess both the directionality and relative timing of gene flow. We find that segments of cave bear DNA still persist in the genomes of living brown bears, with cave bears contributing 0.9 to 2.4% of the genomes of all brown bears investigated. Our results show that even though extinction is typically considered as absolute, following admixture, fragments of the gene pool of extinct species can survive for tens of thousands of years in the genomes of extant recipient species.尽管诸多大型哺乳动物物种在更新世（Pleistocene epoch）末期走向灭绝，但其DNA或可借助过去发生的种间基因混合事件得以留存。然而，关于古代等位基因持续存在的直接实证证据仍较为匮乏。本研究报道了4头更新世晚期洞熊（Ursus spelaeus complex）的多倍覆盖度基因组数据，证实更新世时期洞熊曾与棕熊（Ursus arctos）发生杂交。我们开发了一套分析方法，可同时评估基因流的方向性与相对发生时序。研究结果显示，洞熊的DNA片段仍留存于现存棕熊的基因组中；在所检测的全部棕熊基因组内，洞熊贡献了0.9%至2.4%的基因组组分。本研究结果表明，尽管物种灭绝通常被视为绝对不可逆的，但在发生基因混合后，灭绝物种的基因库片段仍可在现存受体物种的基因组中存续数万年之久。