Exciting times in Botswana. Giant hand axes are among a stash of Stone Age tools discovered there that could tell us more about how the ancestors of modern humans hunted, coped with climate change and migrated through Africa.
Oxford University researchers have uncovered an incredible collection of artefacts including four hand axes, thought to be the worlds largest stone tools in the dry basin of Lake Makgadikgadi in the Kalahari Desert. Their latest finds throw light on how early humans adapted to climate change during the Middle and Late Stone Age, that is, 150,000 to 10,000 years ago.
Researchers say their discoveries show the region has been both wetter, and drier and windier, than it is today. And they estimate the lake has been full several times over the past 250,000 years.
Botswanas Lake Makgadikgadi spills over 66,000 square kilometres and when brimming with water would have been equal to todays Lake Victoria. So far the Stone Age stash found here includes the four big axes each more than 30 centimetres long plus thousands of smaller tools and flakes.
Significantly, many artefacts were found on the lake floor, not around its edge. This suggests ancient hunters might have been sharpening their tools in glee during a dry spell, when low water levels would have forced wild animals to gather at waterholes in the lake bed.
Its evidence of marked human adaptation, according to Professor David Thomas, head of the School of Geography and the Environment at Oxford. Its likely that early human populations would have seen this area as a prolific hunting ground when food resources in the region were more concentrated than at times when the regional climate was wetter and food was more plentiful and the lake was full of water, Prof Thomas said.
He added this challenges the idea that humans were only attracted to big lakes when they were full of water.
Work at Lake Makgadikgadi has been quietly carried out since the early 1990s, when the first axes were found. It is only now the discoveries are being scientifically reported.
Whats also exciting is that Lake Makgadikgadi may have been an important stopover for the human race. Information gleaned at this site, linked with that from similar dry lakes in the Sahara, could enlarge on the Out of Africa theory of human expansion, as archaeologists guess hominids the ancestors of modern humans would have migrated along a wet route through Africa to Europe.
The desert hoard of artefacts has put Botswana previously best known for the Okavango Delta, San paintings and Alexander McCall Smiths fictional Ladies Detective Agency firmly on the archaeological map. According to Prof Thomas, The interior of southern Africa has usually been seen as being devoid of significant archaeology. That has all changed thanks to his teams work, which is part of an ongoing project delving into the history of climate change in Africa.
More research is planned.
Read the Oxford University news release here.