Out of America:: Ancient DNA evidence for a new world origin of late quaternary woolly mammoths
Out of America:: Ancient DNA evidence for a new world origin of late quaternary woolly mammoths
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DOI：
10.1016/j.cub.2008.07.061
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发表时间：
2008-09-09
期刊：
影响因子：
9.2
通讯作者：
Poinar, Hendrik N.
中科院分区：
文献类型：
--
作者：
Debruyne, Regis;Chu, Genevieve;Poinar, Hendrik N.
尽管晚更新世的标志性猛犸，即长毛猛犸（Mammuthus mammoth genius），传统上被认为是一个单一的无性进化谱系的终点，但最近的古生物学和分子生物学研究表明，亚洲更新世猛犸内一定发生了连续的异地物种形成事件，随后在名义分类群之间进行了扩张和杂交[1，2]。然而，北美猛犸种群在这些事件中的作用还没有从古代DNA的角度得到充分的探讨。为了承担这项任务，我们分析了mtDNA从一个大的数据集组成的猛犸样本从整个Holarctica（n = 160），并代表了大部分的放射性碳时间。我们的证据表明，在更新世末期，单倍型起源于新世界人口的特点取代或继承了亚洲和白令西亚西部的特有种。此外，在末次盛冰期，猛犸种群似乎并没有遭受全面的多样性下降，尽管白令陆桥两侧的不同反应。总而言之，“美洲外”假说认为，北美猛犸象向北极大陆其他地区的扩散在猛犸象种群中创造了重要的地理结构，塑造了它们灭绝前进化历史的最后阶段。
Although the iconic mammoth of the Late Pleistocene, the woolly mammoth (Mammuthus primigenius), has traditionally been regarded as the end point of a single anagenetically evolving lineage, recent paleontological and molecular studies have shown that successive allopatric speciation events must have occurred within Pleistocene Mammuthus in Asia, with subsequent expansion and hybridization between nominal taxa [1, 2]. However, the role of North American mammoth populations in these events has not been adequately explored from an ancient-DNA standpoint. To undertake this task, we analyzed mtDNA from a large data set consisting of mammoth samples from across Holarctica (n = 160) and representing most of radiocarbon time. Our evidence shows that, during the terminal Pleistocene, haplotypes originating in and characteristic of New World populations replaced or succeeded those endemic to Asia and western Beringia. Also, during the Last Glacial Maximum, mammoth populations do not appear to have suffered an overall decline in diversity, despite differing responses on either side of the Bering land bridge. In summary, the "Out-of-America" hypothesis holds that the dispersal of North American woolly mammoths into other parts of Holarctica created major phylogeographic structuring within Mammuthus primigenius populations, shaping the last phase of their evolutionary history before their demise.