The Garden of Eden may not have looked much like its traditional image of a lush, fertile corner of the Earth.

Instead, a genetic study of Africa suggests that the origin of humanity lies in a sandy, inhospitable region near the coastal border of Namibia and Angola.

The area is populated by the Bushmen, or San people, who may be the closest thing to a biblical Adam and Eve. The study even gives the co-ordinates as 12.5° E and 17.5° S.

Scientists suggest that the clicking sounds characteristic of the San’s language may be a remnant of original human speech.

The conclusion emerges from the largest study of African genetics yet, conducted by an international team led by Sarah Tishkoff, of the University of Pennsylvania.

Researchers studied genes from more than 3,000 people in 121 of 2,000 population groups in Africa. The study demonstrated that there was more genetic diversity in Africa than anywhere else on Earth, and found that modern African populations evolved from 14 ancestral ones.

Dr Tishkoff said that the study had traced the origin of mankind on the assumption that the oldest population would have the greatest genetic diversity. That diversity decreases as populations migrate away from the origin. “The source area for migration within Africa was in that area that represents today the San homeland,” she said. “What it’s really reflecting is the high level of diversity we are seeing in the San populations. It’s consistent with other studies that those populations have the most ancient lineages.”

She left open the possibility that the San may have themselves migrated at some point from a Garden of Eden somewhere else. “It’s very possible that those populations may have migrated from another region, such as eastern Africa. If that’s the case, 50,000 years ago they might have been in eastern Africa and that might have been the source of the migration,” she said.

The study also calculated the point from which human beings — perhaps a single tribal band as small as 150 people — left Africa about 50,000 years ago to populate the rest of the world. The exit point lies near the midpoint of the African coast of the Red Sea, at the coordinates 37.5° E, 22.5° N.

The genes of African-American populations were also studied, showing, as expected, that their roots lay principally in West Africa, source of the transatlantic slave trade. The ancestry of African-Americans was 71 per cent from the Niger-Kordofanian population of West Africa, 13 per cent European and 8 per cent other Africans.

Remains of the day

- The ruins of Babylon were discovered in the 19th century in Iraq. Saddam Hussein planned to restore the ancient city, complete with the Hanging Gardens

- Satellite images taken in 2004 of Mount Ararat in Turkey led Hawaiian Christian archaeologists to declare they were “98 per cent sure” they had found Noah’s Ark

- The Hollywood director James Cameron claimed two years ago that the tombs of Jesus and Mary Magdalene, found outside Jerusalem in 1980, were authentic. He said it was proved by DNA analysis

Sources: Times Archive; BBC; National Geographic

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