Researchers decode genome of 400,000-year-old prehistoric man - Spiegel Online

The famous archaeological site in the northern Sierra de Atapuerca can anthropologists puzzle. How old are the bones from the Sima de los Huesos karst cave are they really? Which species they belong to? And most importantly: Is it here to the oldest cemetery in human history? One may now be taken for granted: From this place, so proclaims the science journal “Nature”, comes the oldest legible genome of Homo sapiens

.

the new record in the genome-deciphering genetic researchers from the Max Planck Institute for Evolutionary Anthropology have set up. For years, she puzzles Neanderthal DNA of about a dozen caves together throughout Europe. Last year, then they succeeded in the Siberian Denisova a special coup: In a Fingerknöchelchen they made the genome of a hitherto completely unknown to mankind arrest

.

with an age of about 100,000 years, but caught his foray into the genetic history of Homo sapiens. So strong is the genetic material weathered in even older bones that the researchers tried vainly long to read it – until they Huesos have now succeeded in a femur from Sima de los. Crumbles, thinned and chemically modified, but still just detectable, the researchers found 400,000 year-old human DNA.

The bone comes from one of the most spectacular prehistoric man-sites in Europe. By sharp limestone caves crawling, the researchers discovered here already in the nineties not only to the hundreds of cave bear bones, but also on the world’s largest collection of human fossils Stone Age: Around 5000 fragments of a total of at least 28 individuals were able to identify them. A hand ax, unused and unusually carefully carved out of quartzite and ocher, was the only tool discovered – the Spanish archaeologists interpret it as an indication of a burial ritual

. “Amazing crumbly”

protected in the depths of the cave before the cons Nissen of the weather, the bones survived relatively unscathed. “However, most of the bones are amazing crumbly” Matthias Meyer, one of the participating scientists from Leipzig. “They are remarkably light in the hand.”

marriage he and his colleagues dared to approach the human remains, they tested their method on the bones of cave bears. “We have a responsibility not to damage precious fossils without good reason,” says Meyer. After a successful test bears, the researchers selected for the genome-search a particularly strong homo-bones, still in the thick, dense layers were recognizable. It was beneficial to them with this is that these upper leg had once been found in three items. “We were able to drill at the old fracture, without having to draw the outer shape of the bone,” says the Leipzig genetic researchers.

Without any damage however, things went not down – especially since the Gendetektive this time unusually needed a lot of bone material. In Denisova them had 10 milligrams of bone powder – less than a pinch – enough to read the entire genome. This time, however, they had to examine the 200-fold amount until they had deciphered only small parts of the genome. Publish it could now only the so-called mitochondrial DNA derived from the power plants of cells.

That was difficult enough. Because the majority of the genetic material, which ensures the researchers came from bacteria that settle in the sample. And even if the scientists but once encountered DNA clearly of human origin, was among those most any researcher who had kept these bones once in hands. In all this Genmüll track down the few truly neolithic genetic residues, requires a lot of finesse. The Leipzig had to develop new methods to filter out the old, often chemically modified DNA snippet to read and re-assemble them into meaningful text.

Enigmatic Clans

And now what this reveals about the life of primitive man hordes in the glacial plains of Spain? Deciphering gave the Leipzig group especially a big surprise: the sequence that they had finally assembled, similar to that from Denisova

.

Can it be that here members settled that enigmatic clans from Siberia? But how came their descendants then to Asia, and why are they not mingled it with the Neanderthals, which they have to be on the road met?

The news from Spain invites speculation. Geneticists Meyer but warns: “Mitochondrial DNA can lie.” Once before he and his colleagues had gone astray, as she hastily pulled inferences from mitochondrial DNA in Denisova. When they later the deciphering of the genetic succeeded little in the nucleus, they had to revise many.

The breakthrough Meyer sees therefore in the fact that now the proof is performed: human genome can even win hundreds of thousands of years. Until then, however, manage to win the entire genome of the Spanish cavemen, it will probably take a little longer this time. “We still do not even have a strategy on how we should tackle it,” says Meyer.