Matthias Meyer recently published the results of what can be called the most wasteful in the world to draft genome sequencing. Decterov only 0.1% of the genome of the oldest DNA, a molecular biologist from the Institute of evolutionary anthropology of max Planck in Leipzig, Germany, has wasted so much raw data that they would be sufficient for the mapping of the genomes of the ten modern man.
But it was necessary because the DNA in old bones age 430 000 years degraded and contaminated. Feat Meyer showed that the remains, extracted in a cave in Northern Spain, represent the first man and pushed back the estimated time in which the ancestors of the people had to break away from these Neanderthals.
“Start this thing already very ambitious, and dealing with it is actually impressive, said Ludovic Orlando, a researcher of ancient DNA in the natural history Museum of Denmark in Copenhagen. We really have reached the limits of the possible”.
The analysis is devoted to the confusion on the subject of species, which belong to these remains. The report, published in 2013, scientists described avenirovna mitochondrial genome of the femur, which is made of DNA from energy-producing cell structures, which are more in cells than nuclear DNA. And suggested that at least one individual identified in the remains was more closely associated with the group Denisovsky people — whose remains were found in Siberia, than to the European Neanderthals.
“It is wonderful to obtain mitochondrial and nuclear DNA from something vozrasta 430 000 years. It’s just fantastic. And amazing opportunity,” — says Maria Martinon Torres, paleoanthropology from University College London.
These remains are known as hominids, SIMA (Sima hominin), as were found in SIMA de Los Huesos (Spanish for “pit of bones”), a 13-metre cave in the Spanish Atapuerca mountains. Few ancient places are so important or interesting as Shem, in which were stored the remains of at least 28 individuals, along with dozens of cave bears and other animals. These hominids could be crushed to death, but some scholars believe that they were deliberately buried in this place.
Skull hominid Sims have incipient browridges and other traits characteristic of Neanderthals. But other characteristics and uncertainties associated with their age some studies gave them 600,000 years, and some 400 000 — convinced many scientists that the remains may belong to the older form, known as Homo heidelbergensis (Heidelberg man).
The skeleton of a Homo heidelbergensis
The confusion reached its peak when Meyer, his colleague Svante Paabo and their team have identified a mitochondrial connection to the denisovans. However, they hoped that removing the nuclear DNA of the skeleton — which represents a much more ancient line than mitochondrial DNA that is inherited only through the maternal line, — will clarify the situation.
Recovery kernel
The group of Meyer managed to pull out of nuclear and mitochondrial DNA from five samples of Sims, possibly representing different species. The key to their success, according to Meyer, was that since 2006, astronomers carefully cooled the blade teeth and the tissue from the pit to save ancient DNA in anticipation of advanced methods of molecular analysis.
March 14, Meyer’s group reported in Nature that the nuclear DNA showed that the SIMA hominids are, in fact, the earlier Neanderthals. And their age suggests that early ancestors of the human race has diverged from Neanderthals about 550 000-765 000 years ago — too long ago to common ancestors of both groups were Heidelberg people, as suggested by the individual hypotheses.
Now scientists have to find a population that lived 700,000 to 900,000 years ago, says Martinon Torres. She believes that Homo antecessor is known for its remains in Spain the age of 900,000 years, is the strongest candidate for common ancestors, if the same view will be found in Africa or the middle East.
Recent mitochondrial sequence identified by the team, however, again confirm the enigmatic relationship between the SIMA hominids and the denisovans. Meyer says that the ancestors of both groups wore mitochondrial DNA, which is reflected in both groups, but late Neanderthals it’s gone. Such an exception could occur by accident, but now Meyer prefers the hypothesis that yet unknown species from Africa migrated into Eurasia and mixed with Neanderthals, pushing the chronicle of mitochondrial DNA. (In support of this idea, the technology of stone implements came out of Africa into Eurasia about a million years ago and over 250 000 years ago).
It is hard to exclude certain ideas without new data, Meyer said. Need complete or almost complete genome of the SIMA hominids, genetic data or other early Neanderthals.
“It is interesting, and we bend over backwards trying to make sense of it all,” said Chris stringer, paleoanthropology from the natural history Museum in London. Stringer said that the restoration of such old nuclear DNA gives him the hope that scientists can analyze ancient DNA that goes even further back in time. “Instead of trying to understand in the last hundred thousand years,” he says, ” we can start Dating DNA further down the human tree.”