A study in the journal Science pots modern human origins in South Africa back to 300,000 years ago. The DNA from the remains of a 2000 year old boy found at Ballito Bay in Natal during the 1960s has been used to re-write human history – after reconstructing his full genome (and that of 6 others who lived between 2700 and 300 years ago). Three of these people were Khoe-San (which includes Bushmen) and four were of Bantu origin. The genome of the Ballito boy was used to calculate the split between modern humans and earlier human groups and came up with the 300,000 figure. This methodology relies on a constant rate of genetic change – which may prove to be unrealistic as time goes by. For the moment it is catching the headlines. See www.eurekalert.org/pub_releases/2017-09/uoj-sac092817.php …
We are told that evidence now suggests multi region origins of modern humans. For the moment this is confined to Africa alone. If modern humans evolved south of the equatorial zone as well as north of it, in places such as Ethiopia and what is now the Sahara, we have what is known as a fudge – a scientific term for making the best out of contradictory evidence. One might add that if modern humans evolved in multiple locations in Africa – why not outside Africa. The Chinese are keen to have modern humans develop in their neck of the woods, and others have a preference for central Asia. Time will tell. In reality nobody knows for certain where modern humans originated or why. Was catastrophism involved? The link at https://phys.org/print425803447.html … has the same story but notes the 300,000 year date is basically pushing back the San Bushmen evolution. The San, at some stage were affected by admixture with incoming Khoesian people from further north but none of this is really particularly revelatory (apart from the date) and is a matter of genetics catching up with the obvious. Pierre Hallet, in his book, 'Pygmy Kitabu' more or less said this many years ago – prior to genetic research.