Scientists have identified the ancestral homeland of every human alive today. They say all people in the world today once had their home in an area south of the Zambezi river.

The area is now a salt desert, but it was once a vast lake where our ancestors lived 200,000 years ago.

The researchers say our ancestors lived there for about 70,000 years until the climate changed. When fertile green corridors opened up they began to move away, and so began the later migration out of Africa.

"It has been clear for some time that anatomically modern humans appeared in Africa roughly 200,000 years ago," said Professor Vanessa Hayes, a geneticist at the Garvan Institute of Medical Research in Australia.

"But what has long been debated is exactly where these people first appeared and why our ancestors later separated and spread out."

Other researchers in the field, however, have doubts about Professor Hayes's conclusion.

The area named as our ancestors' place of origin lies south of the Zambezi basin, in northern Botswana.

The researchers believe our ancestors settled near a huge African lake system called Lake Makgadikgadi, which has since dried out into winding salt flats.

"It is a truly huge area, and it would have been very wet and warm then," Professor Hayes said. "And it would have provided a suitable habitat for modern humans and the wildlife around them."

Source: BBC Bangla. First published in Bengali on The Agro News.