Scientists reveal the ancestral homeland of modern humans

Pablo Tucker
October 29, 2019

The study provides a window into the first 100,000 years of modern humans' history.

By combining genetics with geology and climate computer model simulations, researchers were able to paint a picture of what the African continent might have been like 200,000 years ago. Articles appear on for a limited time.

"Most people are interested in their past and where we come from. but in our lab to understand our future we really need to understand our past", Professor Vanessa Hayes said as she announced the research done by the University of Sydney and the Garvan Institute of Medical Research.

"Mitochondrial DNA acts like a time capsule of our ancestral mothers, accumulating changes slowly over generations", Hayes said. "Comparing the complete DNA code, or mitogenome, from different individuals provides information on how closely they are related", she said.

They worked with local communities in Namibia and South Africa to collect blood samples.

This was the "first human exploration", said co-author Axel Timmerman of the Center for Climate Physics in South Korea.

While it has always been known anatomically modern humans - homo sapiens sapiens - originated in Africa, scientists have until now been unable to pinpoint the precise location of our species' birthplace.

Geological evidence suggests the homeland region once housed Africa's largest ever lake system, known as Lake Makgadikgadi. Prior to the emergence of modern humans, the lake began to drain because of shifts in tectonic plates that lay beneath it.

To locate the cradle of humanity, the team took samples of mitochondrial DNA from 1,217 Africans. 'What has been long debated is the exact location of this emergence and subsequent dispersal of our earliest ancestors'.

The area is now salt pans, but 200,000 years ago it was home to Homo Sapiens and hosted a population of modern humans for at least 70,000 years, according to a study released in the scientific journal Nature on Monday.

But if it was so ideal, why did our ancestors begin to explore other places between 130,000 and 110,000 years ago, first heading northeast and later southwest from the ancestral home?

"The first migrants ventured north east, followed by a second wave of migrants who travelled south west. A third population remained in the homeland until today", Hayes said.

The authors speculate that the success of this migration was most likely a result of adaptation to marine foraging, which is further supported by extensive archaeological evidence along the southern tip of Africa.

The researchers also investigated the way the climate changed and what role it played in motivating early humans to migrate.

But a dramatic swap to the local weather precipitated by an adjustment within the orbital tilt of the Earth allowed populations to pass northwards.

"These first migrants left behind a homeland population", remarks Professor Hayes.

The research was supported by an Australian Research Council Discovery Project grant (DP170103071) and the Institute for Basic Science (IBS-R028-D1).

Participants for this study were recruited within the borders of South Africa and Namibia.

"But what we hadn't known until the study was where exactly this homeland was".

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