Did ancient human trek out of Africa start in SA?
The modern-day Cradle of Humankind might be 40km outside Johannesburg, but the real thing is on the Southern Cape coast.
That's the belief of European scientists who say they have found "genetic evidence that Southern Africa is a plausible candidate for the cradle of modern humankind".
The evidence comes in the form of maternally inherited mitochondrial DNA, which the geneticists and archaeologists have studied in what they call unprecedented detail.
Writing this week in the journal Scientific Reports, they claim to have found the first "clear signal" that modern humans migrated from the Southern Cape to East Africa between 60,000 and 70,000 years ago.
They believe this "relatively minor genetic influx involving several thousand individuals at most" would have been sufficient to seed populations that went on to colonise the planet.
"The populations in Eastern Africa that resulted from the arrival of new groups from the south were the starting point for the greatest expansion ever undergone by modern humans," write Cambridge University archaeologist Paul Mellars and his fellow researchers.
This expansion was "not only back across Africa but also out of Africa, along the Indian Ocean into South Asia, Southeast Asia and Australasia, and ultimately to the rest of the globe". It is generally acknowledged that Homo sapiens emerged in Africa more than 300,000 years ago.
According to Mellars and co-authors Martin Richards, of the University of Huddersfield in the UK, and Pedro Soares, of the University of Minho in Portugal, these humans in the south and east of the continent were "cognitively modern" and "would not seem out of place if they were raised in any 21st-century society".
Archaeological evidence, particularly from Pinnacle Point in Mossel Bay and Blombos Cave near Still Bay, showed "complex technological and symbolic behaviours" as long ago as 165,000 years.
Later evidence of these behaviours in Eastern Africa was the first clue of a northward migration, but there had been an absence of genetic evidence.
The breakthrough by Mellars and his team came from their focus on mitochondrial DNA in modern-day East Africans, which allowed them to extrapolate that about 2,000 women migrated northward between 65,000 and 60,000 years ago.
The scientists admitted that archaeologists doubted that human symbolic behaviour "radiated outwards from a single source in Southern Africa at such a recent date", but they said their discovery should confound the sceptics.
Mellars said: "This work shows that the combination of genetics and archaeology working together can lead to significant advances in our understanding of Homo sapiens."
• A minuscule discovery in another Cape cave that was occupied at least 80,000 years ago has shed new light on humans' early love of miniaturisation.
A sliver of crystal quartz from Boomplaas Cave, in the foothills of the Swartberg, north of Oudtshoorn, is thought to have been a poisoned arrowhead.
Justin Pargeter, from the Centre for Anthropological Research at the University of Johannesburg, announced his discovery last month in the journal Evolutionary Anthropology.
The anthropologist found the tiny quartz tool in a bag labelled "waste" at Iziko Museum in Cape Town. "It was diminutive, about the size of a small raisin, and weighed less than half a penny," he said.
TECHNICAL TRICKS OF THE STONE AGE
Archeological evidence shows that up to 165,000 years ago, residents of the caves at Pinnacle Point, Mossel Bay and Blombos Cave near Still Bay: Constructed tools from bone;
Made ornaments by perforating the shells of sea snails;
Created the earliest known drawing, using red ochre (clay);
Used heat to treat silcrete, allowing it to be flaked more easily for use in tools;
Incised symbolic designs into red ochre;
Decorated their bodies with red ochre during rituals;
Optimised shell-fishing by tracking lunar phases; and
Made beads from shells.