Origins of modern humans pinpointed in study

Scientists think they have pinpointed the origins of modern humans.
Scientists think they have pinpointed the origins of modern humans. Photo credit: Getty.

Scientists believe they have pinpointed the ancestral home of living humans.

Australian research released on Tuesday in the Nature journal reveals the ancestral homeland of living humans is the southern African countries of Botswana, Namibia and Zimbabwe. 

The exact place of origin is believed to be the Makgadikgadi–Okavango palaeo-wetland in Botswana. Roughly 200,000 years ago, that location was home to an enormous lake which has since broken up into wetlands. This is now a mostly inhabitable place, dominated by deserts and salt pans.

Professor Vanessa Hayes, a geneticist at the Garvan Institute of Medical Research in Australia who worked on the study, said it would have been a suitable habitat for humans.

"It's an extremely large area, it would have been very wet, it would have been very lush. And it would have actually provided a suitable habitat for modern humans and wildlife to have lived," the BBC quoted Hayes as saying.

The researchers believe earlier ancestors stayed in the area for about 70,000 years before any explorers ventured out. It's believed they left the area after a shift in the climate.

The results were determined by looking at the genetic code of mitochondria - known as the powerhouses or energy centres of cells - of more than 1000 living southern Africans. Mitochondria DNA is inherited from people's mothers, meaning maternal lineage can be tracked.

But the study has been met with criticism by some who say mitochondria alone can't be used to reconstruct human origins. 

"You can't use modern mitochondrial distributions on their own to reconstruct a single location for modern human origins," Professor Chris Stringer of the Natural History Museum told BBC.

"I think it's over-reaching the data because you're only looking at one tiny part of the genome so it cannot give you the whole story of our origins."

Others say the research makes sweeping conclusions based only a small amount of DNA from a relatively small location.

The full study can be found here.