The Denisovans - Study Resources

The Genus Homo and the Emergence of Us ANTH 2301 The Denisovans Similar to Homo naledi, the Denisovans are ancient Homo. Only one finger bone, three teeth, a few shards, a partial jawbone, and an askull fragment are among the few remains. Their anatomical characteristics are mostly unknown due to this dearth of information. A portion of the specimens are dated to between 500,000 and 30,000 years ago, and they originate from the Denisova Cave in Siberia, Russia. Based on the little fossil record, conclusions drawn from genetic research, and sediment analysis, these dates have been determined. On the Tibetan plateau, another example was discovered more recently. A monk found a jaw and two teeth in the Baishiya Karst Cave in 1980, but scientists weren't able to examine the jaw until 2010. Based on dating, the specimen was created some 160,000 years ago. According to protein analysis, the jaw belonged to a group that was probably well suited to living at high elevations and was Denisovan in origin (Chen et al. 2019). Since there are so few bones remaining, genetic analysis provide the majority of our knowledge on this species. Nuclear DNA investigations revealed a closer ancestry between Denisovans and Neanderthals than between them and contemporary humans. DNA evidence points to many eras of Denisovan interbreeding with both modern humans and nearby Neanderthal populations. One research that traced the male Y chromosome discovered that the old Denisovan Y chromosome that was previously present in Neanderthals was actually displaced by interbreeding between early humans and Neanderthals. According to Petr et al. (2020), modern humans diverged from Neanderthals around 370,000 years ago, while the Denisovans are thought to have split off approximately 700,000 years ago. Most people agree that H. heidelbergensis was the direct progenitor of Neanderthals, Denisovans, and occasionally even modern humans. One specimen is a first-generation hybrid, with a mother from Neanderthal culture and a father from Denisovan culture (Slon et al. 2018). The discovery of Denisova 11 in Russia's Denisova Cave shows that interactions between Late Pleistocene Homo species led to intermarriage. By comparing the DNA of these three groups, it can be concluded that, with no Denisovan ancestry found in Europe and only 0.1 percent in China, the majority of modern Europeans and Asians got between 1-4 percent of their DNA from Neanderthals. It is now under question whether the genetic makeup of Tibetans, Melanesians, and Indigenous Australians is mostly 3–5% Denisovan and 2.74 percent Neanderthal. The proportions of extinct hominin DNA in contemporary people have been studied by statistical geneticist Ryan Bohlender and his colleagues. They came to the conclusion that the genomes of Pacific Islanders may have been influenced by a third group that is yet unidentified, and that Neanderthals and Denisovans are not the complete story (Rogers, Bohlender, and Huff 2017). Indicators indicating the presence of a group for which no fossils have yet been discovered include statistical and genetic data. We call these populations "ghost populations." For instance, evidence suggests that between 2 and 19 percent of the DNA of four communities in West Africa may have descended from an unidentified archaic hominid that split off from the Neanderthal and human progenitor between 360 KYA and 1.02 MYA (Durvasula and Sankararaman 2020). A recent discovery in China seems to support the theory that there is a third branch within the species Homo.