400 thousand-year-old DNA of man found

 400 thousand-year-old DNA of man found

A study published in the journal Nature revealed that DNA was found in the femur of a 400-thousand-year-old human skeleton.

Evolutionary experts say the research could open a new horizon for the study of human ancestors.

The bone in question was recovered from the 'bone pit' found in Spain, which contains the remains of 28 people from the ancient period.

But the findings raise new questions rather than answer questions about man's complex family tree.

Human remains found in a cave in the northern Spanish city of Burgos, which have been studied for more than 20 years, are thought to belong to a period called the Middle Pleistocene.

Fossils bearing Neanderthal features are thought to be Homo heidelbergensis, or the first members of the Neanderthal lineage.

Because of the degradation of DNA over time, it has never been possible to study the genetics of such ancient human fossils before.

But rapid advances in sequencing technology surprise scientists: "many years ago, geneticists said that DNA older than 60 thousand years cannot be found."says Jose Bermudez de Castro, author of the study and of the Human Evolution Research Center (CENIEH).

From Siberia To Iberia

Professor Svante Paabo, director of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, is a person who has a share in these developments. "Now we can examine the DNA of Man's ancestors hundreds of thousands of years ago."he says.

In this way, scientists sequenced close to the entire mitochondrial DNA (mtDNA). But the coast of this genetic code has produced unexpected results.

Although the remains found in Spain appear to be physically close to Neanderthals, their DNA was found close to those of human remains found thousands of kilometers away in the Denisova Cave in Siberia, which date back 40 thousand years.

Denisova's remains showed that these people were from a group close to Neanderthals. DNA from a small finger bone and tooth was what scientists called "the genome in search of fossils." Because there were not enough fossils belonging to this group.

Using Lost mutations in ancient DNA sequencing, the researchers found that the man found in the "bone pit"had a common ancestor with the man from Denisova that dates back 700 thousand years.

Core DNA

There are various possibilities as to how a person sharing Denisova's DNA came to be in Middle Plestocene Spain.

First, mtDNA in Spain may have come from the common ancestor of the Spanish and Denisova hominids.

Second, the racial mix between Spanish remains (or their ancestors) and another ancient human species may have carried Denisova-like DNA to this western population.

Prof Castro has a theory about who this enigmatic ancestor might be: an older species of human known as Homo Salaf. A million years ago, they lived in the Gran Dolina area, a few hundred meters from the 'bone pit'.

Prof Chris Stringer, of the Natural History Museum in London, said: "We need to have all the data to fully draw the picture of human evolution. We can't get them just from stone tools, just Fossils. The introduction of DNA allows us to take a new look at this event." said.

But since mtDNA is a small and unusual component of our genetic copy, the results are limited. For example, there is no trace of the racial mix between Neanderthals and modern man in the mtDNA of modern man.

For precise information, scientists need to extract the sequence of core DNA derived from the cell nucleus for Neanderthals and compare it with that of modern humans. Likewise, kinship between the Spanish remains and other ancient people will only be possible by decoding the core DNA.

From the point of view of 400 thousand-year-old Spanish fossils, this is difficult to do, but as a result of the stability of the heat in the cave, it is promising that they are well preserved.

"In this case, the question of their kinship to Neanderthals, modern humans and Denisovans will also be solved for sure."he says.