Human genome sheds light on the mystery of human history

Scientists have developed a new statistical method based on the sequence of complete human genomes today to elucidate the events that took place at the dawn of human history.

The method is applied to the genomes of East Asians, Europeans, people of West African and South African descent.

Conducting an analysis of six genomes, the team found that those genes contained traces of genetic material from many of the ancestors of humanity, assembled and created a new combination of time. time by genetic recombination.

Research shows that San people are separated from human communities
Other Africa about 130,000 years ago. (Photo: iStockphoto / Giuseppe Masci)

The main finding of this study is that the San - the indigenous hunter-gatherer group of a nomadic nation in southern Africa - were separated from the earlier communities than previously thought, about 130,000 years ago. Meanwhile, modern ancestors of European and Asian people migrated from Africa only about 50,000 years ago.

Previous studies of human demographics mainly rely on mitochondrial DNA (outside the nucleus of the cell) inherited in the maternal line or the Y chromosome data transmitted from father to son. However, studies are limited because of the small number of gene locations.

This study uses the complete genome of each individual, providing a richer and more complete picture of human evolution.

'With mitochondrial DNA, you can only learn about the family tree of the family (mother line), with only one path from each individual to their ancestors' , Adam Siepel, Associate Professor of Biomedical Statistics. learn to know.

'The difference in our method is not only to use full genome sequences but also to look at them at the same time,' said Ilan Gronau, the study's lead author . 'This is the first study to put all these issues together'.

Previous studies using mitochondrial DNA, Y chromosomes and other signs have estimated that modern humans appeared about 200,000 years ago in eastern or southern Africa; and San people in southern and central Africa - indigenous groups - separated from the African community about 100,000 years ago. But this study shows another result. Accordingly, San people began to separate from about 130,000 years ago.

To conduct the analysis, scientists use an initial statistical approach to deduce the timing of the species' separation, but is somewhat relevant, such as humans, chimpanzees and gorillas.

The study was funded by the Packard Foundation, the National Science Foundation, the National Institutes of Health and has just been published in Nature Genetics.