Entre muitas pessoas, pouca variação genômica

Para ler cum granum salis e atualizado na literatura especializada nesta questão genômica:

By David Brown
Washington Post Staff Writer
Monday, June 22, 2009

There is a simplicity and all-inclusiveness to the number three -- the triangle, the Holy Trinity, three peas in a pod. So it's perhaps not surprising that the Family of Man is divided that way, too.

All of Earth's people, according to a new analysis of the genomes of 53 populations, fall into just three genetic groups. They are the products of the first and most important journey our species made -- the walk out of Africa about 70,000 years ago by a small fraction of ancestral Homo sapiens.

One group is the African. It contains the descendants of the original humans who emerged in East Africa about 200,000 years ago. The second is the Eurasian, encompassing the natives of Europe, the Middle East and Southwest Asia (east to about Pakistan). The third is the East Asian, the inhabitants of Asia, Japan and Southeast Asia, and -- thanks to the Bering Land Bridge and island-hopping in the South Pacific -- of the Americas and Oceania as well.

The existence of this ancient divergence has long been known.

What is new is a subtle but important insight into what happened on a genomic level as the human species spilled across the landscape, eventually occupying every habitable part of the planet.

...

+++++

Read more here/Leia mais aqui.