Genetic and archaeological perspectives on the initial modern human colonization of southern Asia

It has been argued recently that the initial dispersal of anatomically modern humans from Africa to southern Asia occurred before the volcanic supereruption of the Mount Toba volcano (Sumatra) at similar to 74,000 y before present (B. P.)-possibly as early as 120,000 y B. P. We show here that this pre-Toba dispersal model is in serious conflict with both the most recent genetic evidence from both Africa and Asia and the archaeological evidence from South Asian sites. We present an alternative model based on a combination of genetic analyses and recent archaeological evidence from South Asia and Africa. These data support a coastally oriented dispersal of modern humans from eastern Africa to southern Asia similar to 60-50 thousand years ago (ka). This was associated with distinctively African microlithic and backed-segment technologies analogous to the African Howiesons Poort and related technologies, together with a range of distinctively modern cultural and symbolic features (highly shaped bone tools, personal ornaments, abstract artistic motifs, microblade technology, etc.), similar to those that accompanied the replacement of archaic Neanderthal by anatomically modern human populations in other regions of western Eurasia at a broadly similar date.