Abstract：
A number of species have recently recovered from near-extinction. Although these species have avoided the immediate extinction threat, their long-term viability remains precarious due to the potential genetic consequences of population declines, which are poorly understood on a timescale beyond a few generations. Woolly mammoths (Mammuthus primigenius) became isolated on Wrangel Island around 10,000 years ago and persisted for over 200 generations before becoming extinct around 4,000 years ago. To study the evolutionary processes leading up to the mammoths\' extinction, we analyzed 21 Siberian woolly mammoth genomes. Our results show that the population recovered quickly from a severe bottleneck and remained demographically stable during the ensuing six millennia. We find that mildly deleterious mutations gradually accumulated, whereas highly deleterious mutations were purged, suggesting ongoing inbreeding depression that lasted for hundreds of generations. The time-lag between demographic and genetic recovery has wide-ranging implications for conservation management of recently bottlenecked populations.
摘要：
许多物种最近从濒临灭绝中恢复过来。尽管这些物种避免了直接的灭绝威胁，由于人口下降的潜在遗传后果，它们的长期生存能力仍然不稳定，在几代人以外的时间尺度上，人们对此知之甚少。大约10,000年前，猛犸象（Mammuthprimigenius）在Wrangel岛上与世隔绝，并持续了200多代，直到大约4,000年前灭绝。为了研究导致猛犸象灭绝的进化过程，我们分析了21个西伯利亚猛犸象的基因组.我们的结果表明，在随后的六千年中，人口迅速从严重的瓶颈中恢复过来，并在人口统计学上保持稳定。我们发现轻度有害突变逐渐积累，而高度有害的突变被清除，表明近亲繁殖的抑郁症持续了数百代。人口统计学和遗传恢复之间的时滞对最近出现瓶颈的种群的保护管理具有广泛的影响。
