Humans Moved Out of Africa More Recently than Previous Estimates

Humans moved out of Africa much later than previously thought, according to a new study on mitochondrial DNA from human ancestors.

For the study, researchers analyzed mitochondrial DNA from 10 fossilized samples of early human ancestors. The specimens ranged from remains of a man who lived in China some 40,000 years ago, to a man from France who lived about 700 years ago. The study also included three 31,000-year-old skeletons from Czech Republic along with natural mummy Ötzi the Iceman, believed to have lived between 3350 and 3100 B.C., reports Physorg.

"Out of Africa is one of the major events within human evolution. We need to know when it happened," Johannes Krause of the University of Tübingen in Germany and an author of the study told Sciencemag. 

The study results show that humans were living in Europe and Asia before and after the latest glaciations.

According to the latest research, the genetic divergence between people living in Africa and elsewhere in the world began somewhere between 62 and 95 thousand years ago, which fall well within the dates revealed by studies that have been conducted on various tools that ancient humans used. However, recent genetic analyses argue that humans began leaving the continent of Africa some 130 thousand years ago or even earlier.

Researchers in the present study say that previous research has underestimated the number of mutations in a particular generation and so has inaccurate results regarding human migration out of Africa.

Earlier studies rely on a value called as generational mutation rate, which is derived from counting the number of genetic mutations in newborn babies and comparing them with their parents. This value then acts like a molecular clock that can be used to estimate when a particular event might have occurred.

However, this method underestimates the number of mutations and fails to distinguish between a true mutation and a false mutation, the present study found.

The study is published in the journal Current Biology.