The ancient mysteries of the Denis Cave are revealed
New research reveals the deep history of archaic people in southern Siberia
Two new studies shed light on when two groups of archaic people (hominins) – Neanderthals and their mysterious cousins, Denisovans – occupied Denisov's cave in Russia, the only place in the world that was known to be occupied by both groups of hominins and modern people in different time.
For the first time, a timeline was established in the studies, when Denisovites and Neanderthals were present at the site and the environmental conditions they encountered before extinction. The Denisovites, which were discovered only recently, lived at the same time as Neanderthals and modern people roamed the Earth, but were genetically different from both.
Findings published in Nature January 31, 2019 was the result of years of detailed research conducted by a multidisciplinary group of researchers from Russia, Australia, Canada, Germany and the UK.
New studies show that hominins have taken place almost continuously during relatively warm and cold periods over the past 300,000 years, leaving stone tools and other artifacts in the cave sediments. Denisovan fossils and traces of DNA were found at least 200,000 to 50,000 years ago, as well as Neanderthals from 200,000 to 100,000 years ago.
In 2018, a fragment of bone from the cave gave the genome to the daughter of Neanderthals and Denis parents — the first direct evidence of a cross between two archaic hominin groups. New research shows that this girl lived about 100,000 years ago.
Denisov Cave is located in the foothills of the Altai Mountains of Siberia and during the last 40 years has been excavated by archaeologists from the Institute of Archeology and Ethnography of the Siberian Branch of the Russian Academy of Sciences in Novosibirsk.
The site first attracted worldwide attention in 2010, when information was published on the genome derived from a bone of a previously unknown type of hominin, called Denisovans. This is followed by revelations about the genetic history of Denisovans and Altai Neanderthals, based on an analysis of the few and fragmentary remains of hominin.
To date, reliable dates for hominin fossils extracted from cave deposits have remained unclear, as well as dates for DNA, artifacts, and animal and plant remains extracted from sediments.
Fifty radiocarbon datings and more than 100 optical datings support the new chronology of the Denisova cave, as well as the minimum age for a fragment of bone of mixed Neanderthal / Denisovian origin, obtained by dating the uranium series.
One of the studies conducted by Prof. Zenobia Jacobs, a future research fellow at the Australian Research Council (ARC) at the University of Wollongong in Australia, was dedicated to the optical dating of cave deposits, most of which are too old for radiocarbon dating. Optical dating measures the time elapsed since the last exposure to light by particles of quartz or feldspar in a sediment.
Another study conducted by Dr. Katerina Douka from the Institute of Human History. Max Planck, Germany, identified the age of radiocarbon from bone fragments, teeth, and charcoal extracted from the upper layers of the site, and developed a statistical model for integrating all the dating information for the cave.
“This new chronology of the Denisov Cave provides a graph for the rich data obtained by our Russian colleagues on the archaeological and ecological history of the cave for the last three glacial-interglacial cycles,” said Professor Jacobs.
“We had to invent several new methods to date the deepest and most ancient deposits and to build a reliable chronology of deposits in the Denisov Cave,” said Associate Professor Bo Li, geochronologist and ARC researcher at the University of Wollongong.
To determine the most likely age of the archaic hominin fossils, a statistical model was developed at Oxford University in the United Kingdom.
The model combined optical, radiocarbon and uranium series with information on sedimentation stratigraphy and genetic age for Denisovan and Neanderthal fossils relative to each other – the latter is based on the number of substitutions in mitochondrial DNA sequences that were analyzed at the Institute of Evolutionary Anthropology. Max Planck in Germany.
Dr. Douka said that the improved age estimates for hominin fossils, obtained using the new statistical model, “include all available data on the dating of these small and isolated fossils that could be easily moved after deposition”.
Modern people were present in other parts of Asia 50,000 years ago, but the nature of any clashes between them and Denisovites remains open to the assumption that there are no fossil or genetic traces of modern people in place.
For the same reason, another open-ended question is whether the Denisovites or modern people made the oldest bone glasses and personal adornments. [tooth pendants] found in the cave, "said Professor Tom Hyam (University of Oxford), co-author of the study of radiocarbon dating and statistical modeling.
"With direct dates between 43,000 and 49,000 years ago, they are the earliest such artifacts known in all of northern Eurasia."
Professor Richard & # 39; Bert & # 39; Roberts, co-author of both articles and director of the Center for Excellence in Biodiversity and Heritage of Australia, headquartered at the University of Wollongong, said that research has expanded our understanding of the ancient inhabitants of the cave, but still have a lot to learn.
“While these new studies have lifted the veil over some of the mysteries of Denisova’s cave, other intriguing questions remain unanswered as a result of further research and future discoveries,” he said.
This work was supported by the Russian Science Foundation, the Russian Foundation for Basic Research, the state task of the Ministry of Education and Science of the Russian Federation, the Australian Research Council, the European Research Council, the Max Planck Society, and the Royal Society. and the Council for Social and Humanitarian Studies of Canada.
“The time of the archaic seizure by hominin of Denisova’s cave in southern Siberia” by Zenobia Jacobs, Bo Li and others (DOI: 10.1038 / s41586-018-0843-2); and “Estimates of the age of hominin fossils and the beginning of the Upper Paleolithic in Denisova Cave”, made by Katerina Douka et al. (DOI: 10.1038 / s41586-018-0870-z), published in the issue of January 31, 2019 Nature,
Courtesy of Wollongong University
This Phys.org Science News Wire page contains a press release issued by the organization mentioned above, and is provided to you “as is” with little or no comment from Phys.Org employees.