Pictures excavations of the Sima de los Huesos in Atapuerca (Burgos) Javier Trueba / MSF
video Sima de los Huesos, a site located in Atapuerca (Burgos), is the largest accumulation of human fossils and the history since its discovery has brought great finds. The latter has been a (the Femur XIII) of human remains has been sequenced, with new techniques, its nearly complete mitochondrial genome .
Dating from about 400,000 years, this is oldest human DNA in History , whose study has been commissioned Atapuerca team and the Max Planck Institute for Evolutionary Anthropology. The results of this study are published this week in the journal Nature . Matthias Meyer’s team at the Max Planck Institute had very recently sequenced the complete mitochondrial genome a precedent bear the same site and found with human fossils. To do this they had to develop new analytical techniques , given the extreme degradation genetic material .remains outstanding Conservation
Sima de los Huesos is the Atapuerca fossil more of a fossil hominin species . In 1976 skeletal remains were found in at least 28 individuals, whose skeletons are complete, but their bones are highly fragmented, dispersed and mixed, making it difficult to rebuild.
species from Sima de los Huesos presents a combination of archaic features with other incipient Neanderthals , so it is considered evolutionarily related to the latter.
The reservoir conditions, isolated for hundreds of thousands of years in the depths of a karst system does have allowed exceptional preservation of human bones . Mitochondrial DNA is found in multiple copies in the mitochondria of cells and is transmitted only through the maternal line.
DNA Revelations
The researchers then proceeded to compare the extracted Femur XIII from the Sima de los Huesos with that of both modern humans and live-nearest large ape-like fossil species mitochondrial genome: Neanderthals and Denisovans .
From genetic data, researchers calculated an approximate age for the fossil of the Pit of the Bones of 400,000 years, very similar to that estimated by the same procedure for the bear. 430,000 years
Comparison of mitochondrial genome sequences has revealed a greater proximity fossil with Sima with Neanderthals Denisovans , contrary to expectations.
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Denisovans are considered very distantly related to Neanderthals, of which 700,000 were removed years ago. Just have morphological information of this species, found in the Denisova cave in southern Siberia, so it is not possible anatomical comparisons with fossils from the Sima de los Huesos
As revealed by Matthias Meyer.: “ not expected that mitochondrial DNA from the Sima de los Huesos share a common ancestor with the Denisovans instead of the Neanderthals, since fossil Sima show Neanderthal features “.
Given the antiquity of the site, a possible scenario is that humans from Sima are related to the ancestral population from which they evolved separately Neanderthals and Denisovans .
Another possibility, researchers say, is that other than hominins transmitted mitochondrial DNA of Denisovan type to the Sima hominins or their ancestors.
“This work shows that we can now study the DNA of fossils with several hundred thousand years old, opening the possibility of knowing genes of the ancestors of Neanderthals and Denisovans. It’s tremendously exciting,” said the director of the Max Planck for Evolutionary Anthropology, Svante Paabo.
According to Juan Luis Arsuaga , director of the Joint Centre (Complutense University of Madrid Carlos III Institute of Health) Evolution and Human Behavior and Scientific Director Museum of Human Evolution in Burgos: “There is only progress in understanding when it is the unexpected Everything points to a more complex than assumed in the Middle Pleistocene Hopefully future research to clarify the relationships between fossils.. Sima, Neanderthals and Denisovans. “
researchers now propose joint team sequencing mitochondrial DNA from other individuals of the Sima , and even recover some nuclear DNA sequences.
Investigations and excavations at Atapuerca are funded by the Ministry of Economy and Competitiveness, the Junta de Castilla y León and Fundación Atapuerca.
In this research, scientists have participated for the Spanish part Joint Centre (Complutense University of Madrid Carlos III Institute of Health) Evolution and Human Behavior, University of Alcalá de Henares, the National Research Center on Human Evolution in Burgos and the Catalan Institute of Human Palaeoecology and Social Evolution Tarragona.
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