Homo sapiens origins: the fossil evidence
Based on fossil and genetic evidence, Africa is widely recognized as the cradle of our species. Still, from a paleoanthropological point of view, it remains largely unexplored with the noticeable exceptions of east and south Africa and, to a lesser extent, northwest Africa. Therefore, the exact time of emergence as well as the geographical location of the origin of Homo sapiens is largely obscured by a lack of evidence. Chronological and geographical gaps in the fossil record have led to the simplistic notion that a restricted sub-Saharan “Garden of Eden” was the location of a rapid appearance of so-called “early modern human” forms about 200,000 years ago. This model has been largely falsified by the discoveries of Jebel Irhoud (Morocco). At least 300,000 years ago, hominins displaying shared derived conditions with present day humans that distinguish them from other contemporaneous species of hominins, were present at the north-western end of the continent. They were associated with early forms of Middle Stone Age industries that subsequently developed all over the continent. Not only is the timing of Homo sapiens emergence questioned by the Irhoud material, but also the notion of a rapid emergence of “modern humans”. Growing paleontological and archaeological evidence suggests that this emergence is likely a rather gradual pan-African process. It involved a whole range of populations that were neither anatomically nor behaviourally fully “modern”. Finally, new questions are emerging regarding the deeper ancestry of Homo sapiens. Forms represented in Africa and western Eurasia and assigned to Homo heidelbergensis or Homo rhodesiensis seem more and more unlikely to represent a credible common ancestor of Neandertals and extant humans.