Repetitive mammalian dwarfing during ancient greenhouse warming events.
Repetitive mammalian dwarfing during ancient greenhouse warming events.
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DOI：
10.1126/sciadv.1601430
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发表时间：
2017-03
期刊：
影响因子：
13.6
通讯作者：
Abels HA
中科院分区：
文献类型：
--
作者：
D'Ambrosia AR;Clyde WC;Fricke HC;Gingerich PD;Abels HA
在多次极端全球变暖期间，古代哺乳动物的体型缩小了。始新世早期全球碳循环的突然扰动与快速的全球变暖事件有关，这在许多方面与目前的温室效应相似。在这些古代全球变暖事件中最大的一次，被称为古新世-始新世热最大期[PETM;约5600万年前（Ma）]，已经观察到哺乳动物的侏儒化沿着群落结构的其他变化。我们发现，哺乳动物矮化伴随着随后的，较小幅度的变暖事件称为始新世热最大2 [ETM 2（~53 Ma）]。在本研究中分析的四个分类组中的两个中观察到ETM 2期间身体大小的统计学显著性降低，并且在早期马科动物（马）中观察到最明显。在ETM 2期间，最佳采样的马科动物谱系的大小减少了约14%，而在PETM期间减少了约30%。因此，侏儒化似乎是一些哺乳动物在过去全球变暖事件中常见的进化反应，侏儒化的程度似乎与事件的严重程度有关。
Ancient mammals dwarf in size during multiple episodes of extreme global warming. Abrupt perturbations of the global carbon cycle during the early Eocene are associated with rapid global warming events, which are analogous in many ways to present greenhouse warming. Mammal dwarfing has been observed, along with other changes in community structure, during the largest of these ancient global warming events, known as the Paleocene-Eocene Thermal Maximum [PETM; ~56 million years ago (Ma)]. We show that mammalian dwarfing accompanied the subsequent, smaller-magnitude warming event known as Eocene Thermal Maximum 2 [ETM2 (~53 Ma)]. Statistically significant decrease in body size during ETM2 is observed in two of four taxonomic groups analyzed in this study and is most clearly observed in early equids (horses). During ETM2, the best-sampled lineage of equids decreased in size by ~14%, as opposed to ~30% during the PETM. Thus, dwarfing appears to be a common evolutionary response of some mammals during past global warming events, and the extent of dwarfing seems related to the magnitude of the event.