Natural History Museum of Denmark, University of Copenhagen, DK-1350, Copenhagen K, Denmark.
Instituto de Xeoloxía Isidro Parga Pondal, ESCI, Campus de Elviña, Universidade da Coruña, 15071A, Coruña, Spain.
Sci Rep. 2019 Mar 14;9(1):4462. doi: 10.1038/s41598-019-40168-7.
Over 60% of the modern distribution range of brown bears falls within Russia, yet palaeoecological data from the region remain scarce. Complete modern Russian brown bear mitogenomes are abundant in the published literature, yet examples of their ancient counterparts are absent. Similarly, there is only limited stable isotopic data of prehistoric brown bears from the region. We used ancient DNA and stable carbon (δC) and nitrogen (δN) isotopes retrieved from five Pleistocene Yakutian brown bears (one Middle Pleistocene and four Late Pleistocene), to elucidate the evolutionary history and palaeoecology of the species in the region. We were able to reconstruct the complete mitogenome of one of the Late Pleistocene specimens, but we were unable to assign it to any of the previously published brown bear mitogenome clades. A subsequent analysis of published mtDNA control region sequences, which included sequences of extinct clades from other geographic regions, assigned the ancient Yakutian bear to the extinct clade 3c; a clade previously identified from Late Quaternary specimens from Eastern Beringia and Northern Spain. Our analyses of stable isotopes showed relatively high δN values in the Pleistocene Yakutian brown bears, suggesting a more carnivorous diet than contemporary brown bears from Eastern Beringia.
超过 60%的现代棕熊分布范围位于俄罗斯境内，但该地区的古生态学数据仍然稀缺。完整的现代俄罗斯棕熊线粒体基因组在已发表的文献中大量存在，但古代棕熊的线粒体基因组却很少见。同样，该地区史前棕熊的稳定同位素数据也很有限。我们使用从古 DNA 和稳定的碳（δC）和氮（δN）同位素中获取的五个更新世雅库特棕熊（一个中更新世和四个晚更新世）的数据，来阐明该地区该物种的进化历史和古生态学。我们能够重建其中一个晚更新世标本的完整线粒体基因组，但无法将其分配到以前发表的任何棕熊线粒体基因组进化枝中。随后对已发表的 mtDNA 控制区序列进行分析，其中包括来自其他地理区域的已灭绝进化枝的序列，将古代雅库特熊分配到已灭绝的进化枝 3c 中；这一进化枝以前在东白令海峡和西班牙北部的晚第四纪标本中被识别出来。我们对稳定同位素的分析表明，更新世雅库特棕熊的δN 值相对较高，表明它们的饮食比东白令海峡的现代棕熊更具肉食性。
