小柯机器人

2021年10月20日《自然》杂志在线发表了英国剑桥大学Eske Willerslev团队的最新发现。该研究从古代环境基因组学揭示北极生物群的第四纪晚期动态变化。

研究人员报告了对古代植物和哺乳动物群落的大规模环境DNA元基因组研究，分析了来自整个北极地区的535个永久冻土和湖泊沉积物样本，时间跨度为过去5万年。此外，研究人员提出了1,541个当代植物基因组组合，作为参考序列生成。这项研究为北极生物群在环极和区域范围内的长期动态提供了一些见解。

主要发现包括： (1) 在最后一次冰川期，一个相对均匀的草原植物群在北极地区占主导地位，随后在全新世时期出现了植被的区域分化；(2) 某些放牧动物在空间和时间上始终共同出现；(3) 人类似乎是推动动物分布的一个次要因素。(4）较高的有效降水量以及湿地植物比例的增加，对动物多样性显示出负面的影响；（5）西伯利亚北部草原植被的持续存在使一些现已灭绝的巨型动物物种在后期得以生存，包括长毛象（直到3. 9±0.2千年前）和毛犀牛（直到9.8±0.2千年前）；和（6）猛犸象环境DNA的系统发育分析揭示了一个以前没有采样的线粒体谱系。这项发现突出了古环境元基因组学分析用于推进对种群历史和长期生态动态理解的能力。

据悉，在上一个冰川-间冰期中，北极的生物群落经历了巨大的气候变化，但它们的反应的性质、程度和速度并不完全了解。

附：英文原文

Title: Late Quaternary dynamics of Arctic biota from ancient environmental genomics

Author: Wang, Yucheng, Pedersen, Mikkel Winther, Alsos, Inger Greve, De Sanctis, Bianca, Racimo, Fernando, Prohaska, Ana, Coissac, Eric, Owens, Hannah Lois, Merkel, Marie Kristine Freid, Fernandez-Guerra, Antonio, Rouillard, Alexandra, Lammers, Youri, Alberti, Adriana, Denoeud, France, Money, Daniel, Ruter, Anthony H., McColl, Hugh, Larsen, Nicolaj Krog, Cherezova, Anna A., Edwards, Mary E., Fedorov, Grigory B., Haile, James, Orlando, Ludovic, Vinner, Lasse, Korneliussen, Thorfinn Sand, Beilman, David W., Bjrk, Anders A., Cao, Jialu, Dockter, Christoph, Esdale, Julie, Gusarova, Galina, Kjeldsen, Kristian K., Mangerud, Jan, Rasic, Jeffrey T., Skadhauge, Birgitte, Svendsen, John Inge, Tikhonov, Alexei, Wincker, Patrick, Xing, Yingchun, Zhang, Yubin, Froese, Duane G., Rahbek, Carsten, Nogues, David Bravo, Holden, Philip B., Edwards, Neil R., Durbin, Richard, Meltzer, David J., Kjr, Kurt H., Mller, Per, Willerslev, Eske

Issue&Volume: 2021-10-20

Abstract: During the last glacial–interglacial cycle, Arctic biotas experienced substantial climatic changes, yet the nature, extent and rate of their responses are not fully understood1,2,3,4,5,6,7,8. Here we report a large-scale environmental DNA metagenomic study of ancient plant and mammal communities, analysing 535 permafrost and lake sediment samples from across the Arctic spanning the past 50,000 years. Furthermore, we present 1,541 contemporary plant genome assemblies that were generated as reference sequences. Our study provides several insights into the long-term dynamics of the Arctic biota at the circumpolar and regional scales. Our key findings include: (1) a relatively homogeneous steppe–tundra flora dominated the Arctic during the Last Glacial Maximum, followed by regional divergence of vegetation during the Holocene epoch; (2) certain grazing animals consistently co-occurred in space and time; (3) humans appear to have been a minor factor in driving animal distributions; (4) higher effective precipitation, as well as an increase in the proportion of wetland plants, show negative effects on animal diversity; (5) the persistence of the steppe–tundra vegetation in northern Siberia enabled the late survival of several now-extinct megafauna species, including the woolly mammoth until 3.9±0.2thousand years ago (ka) and the woolly rhinoceros until 9.8±0.2ka; and (6) phylogenetic analysis of mammoth environmental DNA reveals a previously unsampled mitochondrial lineage. Our findings highlight the power of ancient environmental metagenomics analyses to advance understanding of population histories and long-term ecological dynamics.

DOI: 10.1038/s41586-021-04016-x

Source: https://www.nature.com/articles/s41586-021-04016-x

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