Neogene hyperaridity in Arabia drove the directions of mammalian dispersal between Africa and Eurasia
Neogene hyperaridity in Arabia drove the directions of mammalian dispersal between Africa and Eurasia
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DOI：
10.1038/s43247-021-00158-y
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发表时间：
2021-05
影响因子：
7.9
通讯作者：
M. Böhme;N. Spassov;M. Majidifard;A. Gärtner;U. Kirscher;M. Marks;Christian A. F. Dietzel;Gregor Uhlig;H. El Atfy;D. Begun;M. Winklhofer
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作者：
M. Böhme;N. Spassov;M. Majidifard;A. Gärtner;U. Kirscher;M. Marks;Christian A. F. Dietzel;Gregor Uhlig;H. El Atfy;D. Begun;M. Winklhofer
现今非洲萨凡纳动物群的演化受到欧亚大陆祖先向非洲扩散的重大影响。在过去的500万年里，这些祖先与当地的类群一起进化成了现存的非洲热带分支。然而，目前还不清楚为什么欧亚大陆的祖先迁移到非洲。在这里，我们使用沉积学观测和可溶性盐的地球化学分析样品从伊朗西部的沉积序列开发一个1000万年的阿拉伯气候的代理记录。我们确定阿拉伯过度干旱集中在8.75，7.78，7.50和625万年前，与北方非洲干旱的阶段。我们认为，这种关系促进了单向哺乳动物扩散到非洲。随后是560万年至330万年前的持续极度干旱时期，这阻碍了非洲哺乳动物群的扩散，并使非洲哺乳动物群在地方上多样化为今天的分支。此后，皮亚琴察中期的温暖使非洲和欧亚大陆之间的双向动物群交流成为可能，这种交流在更新世期间一直持续。
The evolution of the present-day African savannah fauna has been substantially influenced by the dispersal of Eurasian ancestors into Africa. The ancestors evolved endemically, together with the autochthonous taxa, into extant Afrotropical clades during the last 5 million years. However, it is unclear why Eurasian ancestors moved into Africa. Here we use sedimentological observations and soluble salt geochemical analyses of samples from a sedimentary sequence in Western Iran to develop a 10-million-year long proxy record of Arabian climate. We identify transient periods of Arabian hyperaridity centred 8.75, 7.78, 7.50 and 6.25 million years ago, out-of-phase with Northern African aridity. We propose that this relationship promoted unidirectional mammalian dispersals into Africa. This was followed by a sustained hyperarid period between 5.6 and 3.3 million years ago which impeded dispersals and allowed African mammalian faunas to endemically diversify into present-day clades. After this, the mid-Piacenzian warmth enabled bi-directional fauna exchange between Africa and Eurasia, which continued during the Pleistocene.