for more than 50,000 years, the species to which we all belong, Homo sapiens, coexisted and even crossed it (as it is written in our genome) in Eurasia with at least two groups of human beings now extinct. Are the neanderthals, of which we know a lot thanks to the numerous fossil finds, and other people closely related to but much more mysterious call denisovanos . Virtually unknown, these hominids were identified just a decade ago thanks to the DNA of a few remnants: a phalanx of little finger and three teeth in a cave in the mountains of Altai, in Siberia, to which just a few months, they have added a lower jaw discovered in Xiahe, China. With those parts it was impossible to reconstruct its appearance, so that, in the absence of new and significant findings, her face seemed doomed to remain among the shadows.
however, today we can finally take a look. The prestigious journal "Cell" published on the cover of the first portrait reliable the man of Denisova. In particular, that of a girl of this group of human that lived around 80,000 years in Siberia and is notable for its skull width and robust , more even than the neanderthals. Perhaps even more amazing is that the portrait is the technique used to make it, completely innovative, that uses only the DNA from the bone of the little finger . The merit is of a team led by the Hebrew University of Jesusalén (HUJI) and involving researchers from the Institute of Evolutionary Biology (IBE), a joint centre of the University Pompeu Fabra (UPF) and Consejo Superior de Investigaciones Científicas (CSIC).
Eleven traits únicosLa girl denisovana - Maayan Harel"Pass the genetic information to know how it is morphologically an individual seems of science fiction, but what we have achieved," says ABC Tomàs Marquès-Bonet, ICREA research professor, director of the IBE and one of the authors of the study. The researchers studied the genome of the denisovanos, but instead of the sequences gave special attention to the methylation of the DNA, the mark that, like a traffic light, he says what genes are "turned on" or "off" .
In this way, they identified a hundred genes silenced in denisovanos that, however, they are active in sapiens and neanderthals. These data were crossed with the information collected in huge global base of monogenic diseases, which affect a single gene and results in a determined morphological development. Thus, the new technique allowed to reveal up to 56 traits that characterize the denisovanos , of which only eleven are species-specific, while the rest are shared with neandertals or modern humans.
Comparison of the skull of a modern human, denisovano and neanderthal - M. Harel"This little girl we would call attention in the metro due to its robustness"All this has enabled us to reveal the appearance of the owner of the pinky in a digital reconstruction in three dimensions, a young (age-specific is unknown) of eyes and hair brown. "In many features resembles the neanderthals, for instance, in their tilted front and the pelvis large, but others are fascinating, such as your skull is very wide and large dental arch, unique among the hominids," says David Gokhman, of the HUJI and the first author of the study. Marquès-Bonet acknowledge that, probably, this girl "we would call attention in the metro for its robustness". In general, the denisovanos turn out to be higher and stronger than the neanderthals.
Compared anatomical modern human, denisovano and neanderthal - M. HarelLa jaw timelyTo verify the effectiveness of the method, the researchers repeated using the neanderthal genome. The results were compared with a skeleton of the same species and, eureka, the traits predicted agreed between 85% and 90%. In the case of the chimpanzees, the success is increased up to 92%. The data were fantastic, but the team was not something that was going to respaldarles definitely.
"When we send the job to 'Cell' with these two tests passed something very nice: there appeared the first jaw denisovana. Analyzed and seven of the eight characters that we had predicted for that bone, of course without knowing that it existed, they were there. This gave us a power of validation is very strong," he says with satisfaction Marquès-Bonet.
The technique has been tested in neanderthals and chimpanzees, with a success rate of up to 92%Thanks to the DNA we also know that the denisovanos mated with neanderthals and with the ancestors of modern humans that live today in Australia, the Pacific islands, east Asia and southeast asia. Their genes contributed to the ability of tibetans to live at high altitudes, and the ability of the inuit to live in polar regions, to the cross with these populations makes tens of thousands of years. The new reconstruction, financed by the Caixa, does not allow us to know your lifestyle, or how they were able to survive the extreme cold of Siberia, but your anatomy you may be able to teach us more about the evolution and the adaptation to the environment of these elusive members of the human family.
Date Of Update: 21 September 2019, 15:01
