Scientists claim to have traced the homeland of all modern humans to the region of northern Botswana, south of the Zambezi River.
The area is now salt-pans, but 200,000 years ago it was the home of Homo Sapiens and has hosted a population of modern humans for at least 70,000 years, according to a 1945 study published in the scientific journal Nature on Monday.
The group remains in the region until regional climate change causes them to migrate, about 130,000 years ago first to the northeast, then to the southwest.
"We have long known that modern humans originated in Africa about 200,000 years ago," says Vanessa Hayes of the Garvan Institute of Medical Research and the University of Sydney.
"But what we didn't know until the study was where exactly that homeland was."
The area identified in the study was called Makgadikgadi-Okavango, once home to a huge lake, about twice as long as large than the size of contemporary Victoria Lake.
Scientists have come to their conclusions after analyzing DNA samples from 200 Hoysan people, ethnic group living in modern South Africa and Namibia who are known to carry a high fraction of a clone of DNA known as L0.
The researchers then combined the DNA samples with geog data on rainfall, archeological and climatic changes to create a genomic timeline that suggests a permanent L0 line extending back 200,000 years.
Their work creates a kind of genetic map tracing the L0 lineage to show that prehistoric people lived in the region for about 70,000 years before being scattered around the world.
"Every time a new migration occurs, the migration event is recorded in our DNA as a time stamp," Hayes tells AFP.
"Over time, our DNA naturally changes, it's the clock of our history."
Although there were humanoid fossils that preceded the 200,000-year index indicated in the study, the team stated that their L0 data survey allowed us to trace our line directly back to the region south of the Zambezi River.
"We're talking about anatomically modern humans, people living today," Hayes says.
"Everyone who walks in today … actually goes back to L0 is the oldest and everything goes back to this (region)."
The team said they wanted to collect more DNA samples to help to refine their methods and better reconstruct the history of the first movements of our earliest ancestors.  Research Concerns
However, some researchers were not convinced of the findings of the study.
Chris Stringer, who studies human evolution at the UK Museum of Natural History, says that research into human origins is complicated.  "I am very cautious about using modern genetic distributions to conclude exactly where ancestral populations lived 200,000 years ago, especially in a continent as large and complex as Africa," he said in a statement [" posted on Twitter.
" Moreover, with so many studies concentrating on one small part of the genome, or one region, or one stone tool industry, or one "critical" fossil, it does not can cover the full complexity of our mosaic origin e, after considering other data, "he said.  He noted that other studies suggest that our origins may be related to West Africa and East Africa, not South Africa.
Al Jazeera and news agencies