London: A study on genetic diversity of Indian populations has helped scientists confirm that early humans first left Africa around 60-70,000 years ago by crossing into Arabia.
Results of a six-year effort suggested that ancestors of modern people in Europe, Asia and Oceania migrated along a southern route, not a northern route through Egypt as some had supposed, the BBC reported.
It also indicated an important role for South Asia in the peopling of the world.
The researchers found that Indian populations had more genetic diversity - which gives an indication of the age of a population - than either Europeans or East Asians.
This supports the idea that pioneering settlers followed a southern coastal route as they populated East Asia and continued into Oceania.
A route out of Africa via the Arabian Peninsula, along the southern coast of Asia, explained the observed patterns in genetic diversity much better than a route through Egypt’s Sinai desert.
This supports other evidence showing that sea levels might have been low enough around 60-70,000 years ago for humans to cross from the horn of Africa into Arabia via the Bab-el-Mandeb straits in the Red Sea.
The latest findings are based on a new analytical method, which exploits patterns of recombination in human genomes.
“Through a determined approach of analytics and mathematical modelling, we undertook the intricate task of reconstructing the genetic history of a population. In doing so, we now have the tools to explore much more of the human genome,” said IBM researcher Laxmi Parida.
Dr Spencer Wells, director of the Genographic Project, said such methods could provide “greater insights into the migratory history of our species.”
The results are published in the journal Molecular Biology and Evolution.