Hominid Dispersals and Asian Biogeography during the Lower and Early Middle Pleistocene, c. 2.0--0.5 Mya

This paper examines the environmental context of human dispersals into Asia up to 0.5 mya. These dispersals were probably intermittent, often discontinuous, and initially confined to warm grasslands and open woodlands across southern Asia. During the Early Pleistocene, the effects of the uplift of Tibet and the inception of the monsoon were muted by the low-amplitude nature of northern hemisphere glaciations. By the Middle Pleistocene, further uplift, stronger monsoonal circulation, and higher-amplitude, glacial-interglacial cycles made much of Southwest and Central Asia more arid than previously. Two other Mid-Pleistocene developments were important: first, the appearance of Acheulean assemblages, possibly as far east as southern China; and secondly, the first appearance of hominids at latitudes 40-45° N during interglacial episodes. Hominid dispersals in both Europe and Asia were probably broadly similar in that hominids did not habitually live beyond 40° N until c. 500 kya. Rather than dividing Asia longitudinally into areas east or west of the Movius line, latitudinal divisions between warm/hot and cool/cold environments might be more appropriate. KEYWORDS: hominid dispersals, colonization, Asia, monsoon, loess, Lower Pleistocene, Middle Pleistocene, ice ages, Movius Line