Scientists have identified fragments of "Denisovsky" bones in an archaeological layer 200 thousand years old. Human skeletal remains in layers of this age have not yet been found in the Denisova Cave.
Three thousand eight hundred tiny indeterminate fragments of ancient bones from the Denisova Cave in Altai were analyzed by scientists of the Max Planck Institute of Evolutionary Anthropology in Jena using zoo-mass spectrometry and revealed their belonging to specific species of ancient animals of the Paleolithic era. Among this huge pile of fragments, four human fragments were found, which were sent for DNA analysis and determined the type of ancient hominids who lived in the cave 200 thousand years ago. Three fragments from the most ancient archaeological layer belonged to Denisovans and one from a later layer (age 140 thousand years AGO) belonged to a Neanderthal.
The layer containing the fragments of the Denisovans' skeleton contained rich archaeological stone material and many fragments of animal skeletons, from which scientists were able to determine the living conditions of Denisovans 200 thousand years ago. Human skeletal remains in archaeological layers of this age have not yet been found in the Denisova Cave. The finds were discovered in the Eastern Gallery of the cave, where scientists note the absolute preservation and undisturbed time sequence (stratigraphy) of archaeological layers. Stratigraphy is a key factor in determining the age of finds in Paleolithic archaeology, since there are various obstacles to determining the age of Paleolithic finds older than 50-55 thousand years — this is the upper limit of the age determined with high accuracy by the radiocarbon method. Cultural layers are sometimes disturbed by rodent activity, as well as various geological factors. In this sense, the Eastern Gallery can serve as an exemplary object with preserved stratigraphy, where each deposited layer is visible to the naked eye.
In just a few years, the age of the hominids studied has increased by as much as four times - from 50 to 200 thousand years ago. The researchers obtained this opportunity (to clarify the age) thanks to the developed technology for identifying the animal species using mass spectrometric analysis of protein sequences isolated from collagen morphologically indeterminate bone fragments. The total number of bone fragments examined over the past five years has amounted to more than 12 thousand units.
Denisova Cave was discovered in the 1970s, and excavations in it were conducted for a long time by specialists in the Iron and Bronze Ages, who by the mid-1980s had completed studies of the cultural layers of that era. In 1984, in Denisova Cave (Central Hall, the oldest layers) a human milk tooth was found, which could be identified as Denisovsky only 30 years later, when the Institute of Archaeology began to actively cooperate with the Institute of Evolutionary Anthropology of the Max Planck Society. In the course of this collaboration, in 2010, first mitochondrial and then nuclear DNA (2012) of a new taxon of ancient man from Denisova Cave was isolated for the first time. It was a fragment of the phalanx of the little finger of the girl. Later, several more bones of Denisovites were added to it. To date, more than 10 bone remains of Denisovans have been found, including teeth, skull fragments, phalanges and several morphologically indeterminate bone fragments.
In addition to bone fragments of Denisovans, archaeologists also found the remains of Neanderthal bones, which led them to think about the coexistence and contact of these populations of ancient people. And in 2018, their assumptions were once again confirmed by genetic analyses — one of the fragments belonged to a hybrid girl in the first generation - from a Neanderthal mother and a Denisovan father! Moreover, a detailed study of DNA showed that a Denisovan several generations ago also had Neanderthals in his maternal ancestors. It was also possible to detect the human identity of the fragment of the hybrid girl thanks to the use of the zoo-mass spectrometry technique - ZooMS.
For more than 30 years of excavations (since 1984), archaeologists have managed to find not so many bone remains of Denisovans and Neanderthals. With the advent of zoo-mass spectrometry technology, it became possible to identify the ownership of the smallest bone fragments, of which many thousands have accumulated over decades of excavations in the cave. This study showed that out of many thousands of animal remains, only a few belong to humans. Nevertheless, with the introduction of the method of mass spectrometry of peptide sequences isolated from bone remains, the total number of bone fragments of ancient hominids from Denisova Cave immediately increased by a third. These studies were conducted by a group of scientists from Oxford and Jena under the leadership of Katerina Duka.
"Anthropological remains are usually counted in units, whereas animal bones in the form of fragmented material in caves are usually tens of thousands—" explains Mikhail Shunkov, head of the Department of Stone Age Archaeology of the IAET SB RAS, Corresponding member of the RAS, Doctor of Historical Sciences. - In addition to primitive man, animals, mainly ungulates, were hunted by his direct competitors - predators: cave hyenas, bears, wolves. In the same archaeological layers where fragments of human bones were found, there were also stone tools — an industry of the early stage of the Middle Paleolithic, which is not found anywhere in Northern Asia except Denisova Cave. At the same time, there are quite close analogies with Paleolithic stone tools of the Middle East."
"We assumed that the Denisovans came to Altai about 300 thousand years ago from the territory of the Middle East, because in the Levant and in the Denisova Cave, similar stone industries were found in archaeological layers of this age—" the scientist noted. "Paleogenetic data helped us to make sure that the Denisovans were the first inhabitants of the Denisova cave, as well as to identify the ownership of the oldest stone tools — they were made by Denisovans."
Archaeologists note two main forms among the stone tools of the Middle Paleolithic — the scraper and the point, which gradually changed their shape, their working edge improved. The so-called plate industry gradually developed. Denisovans were able to make thin and elongated stone plates. Knife-type microplates in the Upper Paleolithic period were no longer used as an independent tool, but as a blade-insert into the groove of a composite tool with a handle made of wood or bone. At all stages of the development of stone tools, scientists note the continuity of technologies. The appearance of a new tool did not mean the cessation of the manufacture of more archaic varieties of tools. Over time, the technology has improved. Among the tools of the Upper Paleolithic type there are many pointy points, miniature punctures, chisel-shaped tools. Together with ornaments made of bone and ornamental stone in the same layers there are tools with which they could well have been made.
Genetic traces of Denisovans in the East were found in the genes of the modern population of the mountainous part of Tibet, as well as the aboriginal population of Australia and the islands of Oceania (5-6%). Nevertheless, the remains of Denisovans have so far been found only in two caves. At the same time, the level of genetic diversity of Denisovans, according to the materials of DNA studies of bone remains, is very high. This means that the population of Denisovans was numerous, had an exceptionally wide distribution up to the tropical latitudes of East and South Asia, and lived in the Altai for a very long period - about 300 thousand years. As part of the Denisov genome obtained from the phalanx of the little finger, the presence of alleles defining dark skin, brown eyes and brown hair was established. But more ancient representatives of this species of hominids could look different. In this regard, researchers call the bearer of the culture of the beginning of the Upper Paleolithic (about 50 thousand years ago) Homo sapiens altaiensis, and the term Denisovans use when referring to the older representatives of this taxon.
The article was published in the journal Nature Ecology and Evolution
PHOTO: Employees of the Institute of Archaeology and Ethnography of the Siberian Branch of the Russian Academy of Sciences during archaeological work in one of the galleries of Denisova Cave © RIA Novosti
Source: naked-science.ru, sci-dig.ru
Certificate of registration of mass media ЭЛ № ФС 77 - 78868 issued by Roskomnadzor on 07.08.2020