Human migrations in the Ice Age

29 Jan 2011

This story can be found all over the internet, at www.eurekalert.org/pub_releases/2011-01/aaft-mhr02111.php and at www.nytimes.com/2011/01/28/science/28africa.html?_r=3 and at www.sciencenews.org/view/generic/id/69197/title/Hints_of_earlier_human_exit_from_africa/ and it all comes from a paper in the journal Science January 28th issue which is all about the discovery of a cache of stone tools in eastern Arabia, in what is now the Emirates. The cache of tools is said to date back to the last Inter Glacial episode, 125,000 years ago, or possibly somewhat nearer 100,000 years ago when glacial conditions had kicked in. Modern humans are thought to have evolved in east Africa as early as 200,000 years ago but they aren't thought to have begun their migration along the bottom of southern Asia until around 50,000 years ago (the classic Out of Africa storyline). This theory has been weakened of late by a lot of finds of material attributed to modern humans - with little or no skeletal material to back them up. It is said in the paper that the toolkit resembles those known from East Africa, and its a short hop across the Red Sea to Arabia - but other anthropologists are not certain. For example, Ravi Kanisetter of Karnatak University in Dharvad, India, was supportive of the idea of Arabia as a gateway to Asia. The oldest Indian toolkit assigned to modern humans dates from before 74,000 years ago so the find fits that earlier discovery. Other archaeologists and anthropologists are not so sure and say the Arabian tools differed slightly from contemporary African examples - they are somewhat thicker. Instead, they favour the idea that people from India colonised eastern Arabia - and the African end of things is allowed to rest. Hence, there is the prospect there was a migration to the west rather than to the east, a novel idea that cannot be disputed when Australian and New Guinea evidence is added to the equation. In addition, and adding to the mix, the paper comes a couple of weeks after some tools and teeth found in a cave in Israel were dated even earlier, and likewise attributed to modern humans rather than the endemic Neanderthals. The recent paper highlights how such little evidence is used to construct grand schemes on human origins.