Paleogenetics from the United States found in the DNA of Denisovans and Neanderthals traces of an extremely ancient population of people that separated from the general tree of human evolution almost 2 million years ago. They met with a common ancestor of Denisovans and Neanderthals about 750 thousand years ago, scientists write in the journal Science Advances.
Alan Rogers, a professor at the University of Utah in Salt Lake City (USA), and his colleagues writes:
“Recently, we learned that the ancestors of the modern inhabitants of Eurasia came into contact with ancient people, Neanderthals and Denisovans. We managed to show that hundreds of thousands of years before that, both came into contact with an even more archaic population of people who first settled in the territory Europe and Asia”
10 years ago, Russian anthropologists and paleogenetics, announced the discovery of the so-called Denisovans, a previously unknown species of people whose remains were found in the Denisova Cave in Altai. Scientists were able to make this discovery due to the fact that they were able to extract and study fragments of the Denisov genome, preserved inside the teeth and knuckles.
Initially, their discoverers believed that the ancient inhabitants of Altai were relatives of Neanderthals living in the Denisova Cave about 50 thousand years ago. Subsequently, it turned out that Denisovans appeared much earlier and were a separate subspecies of people whose traces of DNA were preserved in the genomes of modern Polynesians, Indians of South America and some peoples of Southeast Asia.
The similarities in the DNA structure of Denisovans and Neanderthals, Rogers says, led many scientists to believe that they were close relatives, whose common ancestor left Africa about 600-800 thousand years ago. In the past five years, scientists have been fiercely arguing about what happened next and when the “purebred” Homo neanderthalensis and their Altai “cousins” appeared.
In particular, Rogers and his colleagues suggested three years ago, comparing the DNA of Neanderthals and Denisovans, that their ancestors split unexpectedly early, about 700 thousand years ago. Their opponents, anthropologists believe that this happened much later, referring to the fact that the small size of the populations of ancient people distorted the results of Rogers calculations.
First people of the earth
These discrepancies and disputes, as Rogers found out, were caused by the fact that the DNA of Neanderthals and Denisovans hides traces of another, much more ancient population of people, which is extremely distant in genetic terms from all other known representatives of the genus Homo.
Paleogenetics came to this conclusion using a new technique that allows us to find common features and differences in the genomes of modern Eurasians, Africans, as well as Neanderthals and Denisovans. Comparing how often common and unique mutations occurred for each of these representatives of the genus Homo, scientists tried to understand whether traces of previously unknown groups of ancient people were hidden in their genomes.
A large number of common mutations in the genomes of Neanderthals and Denisovans, as well as their absence among Europeans and Africans, indicated that the common ancestor of the first two species came into contact with a previously unknown and very ancient population of people. The number of this group of ancient Homo was quite large, reaching a mark of 20-50 thousand individuals.
Scientists’ calculations show that its representatives separated from the general tree of human evolution about 2 million years ago. This suggests that these ancient hominids are among the Homo erectus, bipedal people, the oldest “Eurasian” remains of which were found in Georgian Dmanisi at the end of the last century.
Representatives of this ancient species of hominids, as shown by the calculations of Rogers and his colleagues, have existed in Eurasia for a very long time. According to researchers, they should not have disappeared earlier than 750 thousand years ago, when they met with the first populations of common ancestors of Neanderthals and Denisovans who left Africa. Subsequently, as scientists suggest, these people could additionally contact the Altai Homo.
According to researchers, these ancient people survived about the same fate as the Neanderthals and Denisovans, who disappeared about 50 thousand years ago under the onslaught of new “migrants” from Africa, the ancestors of modern Homo sapiens. Studying their genetic heritage, as Rogers and his team hope, will help uncover the mystery of their disappearance and reveal their role in the evolution of mankind.