Friday, December 20, 2013

The little finger reveals the turbulent history of mankind - The Point

The – Published on 12/20/2013 at 11:18 am

Genetics says that Neanderthals, homo sapiens and other archaic human groups have been together many children.


At the end of the prehistoric Neanderthals and other mysterious groups of people crossed our homo sapiens ancestors physically and sometimes sexually caves in Siberia and Europe. It is unclear whether they lived happily, but we know they had many children. And even if all are off, a part of their genetic heritage still survives today in us. This story is a little bird told. More precisely a bit of toe belonging to a Neanderthal woman who lived here 50,000 years in a cave in the Altai Mountains.

Geneticists launched since 2006 traces of Neanderthal, are able to read the DNA of the bone and reconstruct the genome of this woman. Their results, unprecedented accuracy, shed new light on the history of primitive humans disappeared, but also the genetic melting pot that the rest of us modern humans, are heirs. With the exception of Africa, all modern humans have in their genome and 1.5% to 2.1% DNA inherited from Neanderthals, according to the new estimates. As for Asian populations and Indians, about 0.2% of their genome was caused by a distant cousin of Neanderthal man Denisova. A proportion that rises to about 6% for the aborigines of Australia, Papua New Guinea and some Pacific Islands.

Published Wednesday in the journal Nature , “the study shows how the history of humans and hominins (their missing cousins, Ed) was complicated at the time, “summed up one of the authors, Montgomery Slatkin. “We know there were many crosses, and there were probably others that we have not yet discovered,” he said in a statement released by the University of California, Berkeley . Neanderthals and dénisoviens could also mate them: the first gave at least 0.5% of its DNA to the second line. DNA analysis also revealed the presence of a fourth thief in this family imbroglio: the human genome Denisova contains 2.7 to 5.8% of the genome of a human “archaic” old at least a million years, previously unknown to the battalion!

Genetic essence of homo sapiens

“This old population of hominins existed before the Neanderthals, the dénisoviens and modern humans are separate,” says Kay Prüfer, the Max Planck Institute for Evolutionary Anthropology Leipzig (Germany), lead author of the study. “It is possible that this human is unknown homo erectus that is known by its fossils. Additional studies are needed to confirm or refute this possibility,” says the researcher.

With further comparison, the geneticists believe even be able to identify the specific genetic sequences modern humans, to the exclusion of all other primates, apes, Neanderthals or dénisoviens . The genetic nature of homo sapiens would in a “relatively short” list (87 specific genes and some thousands of variants), as Svante Pääbo, director of the Max Planck Institute and a pioneer of ancient DNA. “This is a catalog of genetic traits that differentiate modern humans from all other organisms, whether living or extinct. I believe that within hide some things that made the huge expansion of populations can human, their culture and their technology over the past 100 000 years, “he said. “You can not point a finger gene and say this is what is responsible for the language or another trait that modern humans have exclusivity,” says Montgomery Slatkin. “But this list of genes will tell us about the changes that the human lineage has known, even if these changes are likely to be very subtle.”

much for the great history of mankind. For the record, the Neanderthal owner toe was perhaps the result of an incestuous liaison. The study shows indeed that his parents shared the same blood: half-brother and half-sister from the same mother, uncle and niece, aunt and nephew or double first cousins ??… This is not necessarily proof of dissolute morals, but rather a sign that the population density in Neanderthals and dénisoviens was very low, which resulted in more frequent inbreeding today.

No comments:

Post a Comment