Scientists have concluded that modern humans, Homo sapiens, all originated from a single point in southern Africa roughly 200,000 years ago.
A study published Monday in the journal Nature suggests that parts of Botswana’s Makgadikgadi salt pans — found to have once been Africa’s largest lake system — housed modern humanity’s very first ancestors.
According to the researchers, humans thrived in the area for about 70,000 years before drastic climate change forced them to migrate out of the region, and consequently out of Africa.
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“It has been clear for some time that anatomically modern humans appeared in Africa roughly 200,000 years ago,” study lead Vanessa Hayes, a professor at the Garvan Institute of Medical Research, said in a press release.
“What has been long debated is the exact location of this emergence and subsequent dispersal of our earliest ancestors.”
Previous fossil evidence suggested the first humans originated in other parts of the continent, namely in Eastern Africa as well as to the northwest in Morocco, but Hayes and her colleagues’ study claims to have made a breakthrough, going so far as to even pinpoint the specific region.
“We not only suggest southern Africa, but we pinpoint southern Africa — plus the region we call the Okavango-Makgadikgadi region,” said Hayes in a video presentation on the study.
According to another researcher from Hayes’ team, archaeological and fossil findings were used geographically locate the now arid and salt-cracked area of Makgadikgadi as the source of modern humans.
“Prior to modern human emergence, the lake had begun to drain due to shifts in underlying tectonic plates,” said Dr. Andy Moore in a press release.
“This would have created a vast wetland, which is known to be one of the most productive ecosystems for sustaining life.”
The study also suggested that other climate events, such as shifts in rain patterns, led to the opening of several green corridors for our early ancestors to migrate out of their homeland for the first time.
According to Hayes, the first wave of migrants travelled northeast when the first green corridor opened 130,000 years ago, while a second wave migrated southwest when their corridor opened 110,000 years ago.
A third group remained and adapted to the land, forming the population of people living there today.
To further trace genetics and changes over generations, Hayes and her team collected hundreds of blood samples containing mitochondrial DNA which they then combined with geography and climate research to produce their findings.
Some critics, however, say a study of a single region wouldn’t be able to fully comprehend the complexity of both human development and migration.
In an interview with BBC News, professor Chris Stringer of the Natural History Museum said that mitochondrial DNA — the piece of DNA that’s passed down from mother to child — can’t be used to locate a single location for modern human origins.
“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,” said Stringer.
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