The ancient secrets of Denis Caves have been discovered
New studies reveal the deep history of archaic people in southern Siberia
Two new studies highlighted when two groups of archaic people (hominines) – Neanderthals and their cousins, Denisovci – occupied Denis's cave in Russia, the only place in the world that they knew were occupied by both hominine groups and modern humans at different times.
For the first time, studies determined the time frame when Denisovanci and Neanderthals were present at the site and the surrounding conditions they faced before extinction. Denisovci, who were only recently discovered, lived at the same time that Neanderthals and modern humans were lurking on the Earth but were genetically different from both.
Finds, published in Nature January 31, 2019 is the result of many years of detailed research by a multidisciplinary team of researchers from Russia, Australia, Canada, Germany and the United Kingdom.
New studies have shown that hominins have occupied the site almost continuously through relatively hot and cold periods over the past 300,000 years, leaving behind stone tools and other artefacts in jam deposits. Fossils and DNA traces of Denisovana are at least 200,000 to 50,000 years ago, and those of Neanderthals are 200,000 to 100,000 years ago.
In 2018, the fragment of the cave from the cave gave the genera of the daughters of the Neanderthal and Denisian parents – the first direct proof of the crossing between the two archaic hominine groups. New studies reveal that this girl lived about 100,000 years ago.
The Denis Cave is located at the foot of Siberia, for 40 years archaeologists from the Institute of Archeology and Ethnography (Siberian Branch of the Russian Academy of Sciences) excavated in Novosibirsk.
The site first came to world attention in 2010 by publishing the genome derived from the fingers of a previously unknown type of hominine named Denisovani. Further discoveries were about genetic history of Denisovans and Altay Neanderthals, based on the analysis of several and fragmented hominine residues.
Until now, reliable dates for hominid fossils found in cave beds have remained unimaginable as well as dates for DNA, artifacts and animal and plant residues from sediments.
Fifty years of radioactive carbon age and more than 100 years of optical dating support a new chronology for Denisov's cave, as well as the minimum age for a bone fragment of a mixed neanderthal / denisian origin obtained by dating uranium series.
One of the studies, led by Professor Zenobia Jacobs, the Australian Research Council (ARC), with the University of Wollongong in Australia, included optic dating of the sedimentation caves, most of which was cut off for radiocarbon dating. Optical dating measures the time of quartz or feldspar grain in the sediment that was last exposed to light.
The second study, led by Dr. Catherine Douka of the Max Planck Institute for Human History, Germany, received radiocarbon time from the bone, tooth and charcoal fragments obtained from the upper layers of the site and developed a statistical model for integration of all information about cave.
"This new chronology of Denisov's cave provides a time frame for the wealth of information our relatives gathered about the archaeological and ecological history of the caves during the past three ice-interglacial cycles," said Professor Jacobs.
"We had to invent some new methods to present the deepest and oldest deposits and build a robust chronology for sediments in Denis Cave," said associate professor. Dr. Li Li, Geocologist and Associate of ARC Future at Wollongong University.
To determine the most probable age of archaic hominine fossils, a statistical model was developed at Oxford University in the UK.
The model combines the age of optical, radiocarbon and uranium series with stratigraphic deposition and genetic data for Denisovana and Neanderthal fossils compared to others – the latter is based on the number of substitutions in the mitochondrial DNA sequences that were analyzed. at the Max Planck Institute for Evolutionary Anthropology in Germany.
Dr. Douka says improved age estimates for hominid fossils obtained using a new statistical model include "all dating data available to these small and isolated fossils that could easily be moved after depositing."
Modern people were present in other parts of Asia 50,000 years ago, but the nature of any encounter between them and Denisovana remains open to speculation in the absence of any fossil or genetic traces of modern people there.
"For the same reason, one more open question is whether Denisovani or modern people made the oldest bone points and personal ornaments." [tooth pendants] found in the cave, "said Professor Tom Higham (University of Oxford), co-author of radiocarbon dating and statistical modeling studies.
"With direct dates from 43,000 to 49,000 years ago, the earliest such artefacts are known throughout northern Eurasia."
Professor Richard & # 39; Bert & # 39; Roberts, co-author of both papers and director of the Center for Excellence for Australian Biodiversity and Heritage, headquartered at Wollongong University, said the studies expanded our understanding of ancient cave inhabitants but has still been. a lot to learn.
"Although these new studies have raised the veil of some of the secret Denis Caves, other intriguing questions remain for further exploration and future discoveries," he said.
The research was supported by the Russian Foundation for Science, the Russian Foundation for Fundamental Research, the Ministry of Education and Science of the Russian Federation, the Australian Research Council, the European Research Council, the Max Planck Society, the Royal Society. , and Canada's Social and Humanities Research Council.
"The Time of Archaic Occupation of Denin Caves in Southern Siberia" by Zenobie Jacobs, Bo Li and Associates (DOI: 10.1038 / s41586-018-0843-2); and "Hominine Fossil Age Estimates and the Beginning of the Upper Palaeolithic in Denis Cave" by Katerine Douka et al. (DOI: 10.1038 / s41586-018-0870-z) were published on January 31, 2019. Nature.
Provided by Wollongong University
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