The uplift of the himalaya-tibetan plateau and human evolution: An overview on the connection among the tectonics, eco-climate system and human evolution during the neogene through the quaternary period

Abstract

This paper reviews the recent studies on the uplift of the Tibet-Himalaya mountains (TH) and its association with the human origin and evolution through the climate and ecosystem changes in Afro-Eurasian continents. The uplift of TH since the late Tertiary Era gradually formed the Asian monsoon system and dry climate in southwest Asia through North Africa. Meanwhile, during 5–10 Ma the formation of the Rift valley of east Africa brought about drier climate and grassland in the equatorial east Africa, which has an important implication to the early hominid evolution. The uplift of TH also caused and/or enhanced decrease of atmospheric CO2 content through chemical weathering of mountain slopes, which has induced colder climate through the late Tertiary to the Quaternary Era. The lowering of CO2 content caused expansion of grassland of the C4-plant and associated evolution of Ungulata (e.g., antelope), which may have also affected the early hominid evolution. The Quaternary period was characterized with glacial cycles of 40–100k year periods. The ice/snow albedo feedback of Tibetan Plateau may have played as an amplifier of the climate change of this Era. Large temporal and spatial variability of wet/dry zones in east Africa affected by the glacial cycles is very likely to induce further evolution and diffusion, including the migration to Eurasia. During this period, the cold climate and weakened Asian monsoon formed a broad zone of steppe and grassland in central Asia through Europe, and enabled large variety of herbivorous mammals there. The codependent relation between these mammals and the hominid species was essential for the evolution of the later hominid species (Homo erectus) to the modern hominid (Homo sapiens). Under the warm and stable climate of the Holocene since 10 ka the modern hominid heuristically started agriculture and civilization, which has, however, been a new epoch called “the Anthropocene” when the human beings are changing the earth system itself.