New discoveries made at Denisova Cave, Siberia.
Three Denisovans and a Neanderthal: five new 200,000-year-old fossil bone fragments have come from Denisova Cave in southern Siberia. A four-year, painstaking search produced the finds, from a study analysing almost 4,000 bone fragments found in the cave.
The researchers from Austria, Germany, and Russia, led by Diyendo Massilani, extracted and analysed ancient proteins and DNA from the bones. They used a biomolecular method called peptide fingerprinting, a form of mass spectroscopy, to examine the shattered bones, all no larger than 4cm long. Until recently, such fragments would have been considered unidentifiable. But the peptide fingerprinting allowed the research team to identify five bones with the peptide profile of humans from the earliest occupied levels of the cave. Four of the human bones contained enough DNA to allow the reconstruction of their mitochondrial (mtDNA) genomes. Three aligned with the Denisovan mtDNA type, and one with that of Neanderthals. These are some of the earliest human remains ever to be genetically sequenced.
We now know that the Denisovans appeared at the cave during a warmer period, when the climate resembled that of today. They hunted herbivores such as bison, deer, gazelle and the fast-moving saiga antelope, even the formidable woolly rhinoceros. At the time, the cave was in a strategic location close to the floodplain of the nearby Anui River, where raw material for making stone tools was readily available. This hunting tradition endured for thousands of years. The first Neanderthals then appeared in the cave around 159,000 to 130,000 years ago, although, of course, they may have been in the region earlier.
This important cave is, so far, the only known site to have been periodically visited by the Denisovans, Neanderthals, and us, Homo sapiens.
Image: excavations in the eastern chamber of Denisova Cave.
Credit: IAET, Siberian Branch Russian Academy of Sciences