WASHINGTON. - The humanity could have been about to extinguish 70.000 years ago, when the Earth was only inhabited by about 2.000 individuals threatened by natural disasters and illnesses, according to a genetic investigation of the University of Stanford (California) and the Academy of Sciences of Russia, published in \'American Journal of Human Genetics\'.
According to the theory of these investigators, during that lingering period, considered critical due to the scarce number of the inhabitants in the planet, these people were exposed in a bigger measure to illnesses, conflicts and natural disasters.
And that means that the humanity confronted in that period a high disappearance risk if anyone of these negative factors had been overturned with more force than other.
The study also suggests that the humans (\'homo sapiens sapiens\') carried out its first outside of Africa trip 70.000 year ago.
On the other hand, this research affirms that contrary to the chimpanzees that are the man\'s genetic relatives, all the human beings have basically the same DNA (deoxyribonucleic acid).
The experts assure that a group of chimpanzees -of those that it is believed that humans were divided in diverse groups five or six million years ago -, can have more genetic variety to each other that those more than 6.000 million individuals that inhabit the Earth at the present time.
Those millions of years could be enough so that the chimpanzees and the man developed substantial genetic differences, they affirm. Because of that all the humans have virtually identical DNA, the experts in genetics are investigating the slight differences among the diverse minorities.
One of the methods involves the called microsatellites that are repetitive segments of DNA and that differ among the diverse groups. These microsatellites have a high mutation, or error that has been gone through generation by generation, transforming them into a valuable tool for the studies when divergences are detected in two population groups.
During the investigation, the scientists of Stanford and Russia compared 377 microsatellites marked in DNA, taken of 52 regions around the world. The analyses revealed a near genetic similarity between two populations that lived off the hunt in the sub-Saharan África.
They also threw light on the separation of the populations of hunters and farmers of Africa that could have happened in between 70.000 and 140.000 years ago.
Topic: Ouch! It was pretty close... (Read 499 times)