These GEITP pages have often discussed evolution and dispersal (migration) of hominins (i.e. any species of early human that is more closely related to humans than chimpanzees — including modern human) during the past 6 million years. The time period — during which the Neanderthals and the Denisovans lived, and where they were geographically distributed — is still being studied. Denisovan remains are known only from the locality of Denisova Cave, located in the foothills of the Altai Mountains in southeastern Siberia [the 4th attachment (editorial) shows a nice photo of the front of that cave]. Neanderthal remains have also been recovered from “deposits” (fecal material) of this cave. The cave consists chiefly of three large chambers (Main Chamber, East Chamber and South Chamber), each containing deposits several meters deep.
Excavations have yielded Middle Paleolithic (~300,000 to 30,000 years ago) stone artefacts and a variety of Upper (Late) Paleolithic (~50,000 to 10,000 years ago) artefacts — as well as remains of (non-human) animals and plants. The fragmentary remains of four Denisovans, two Neanderthals, and a daughter of Neanderthal and Denisovan parents (providing evidence for admixture between these two populations) — have also been recovered; their genomes have been sequenced, as has DNA extracted from the Pleistocene (i.e. geological epoch which lasted from ~2,588,000 to 11,700 years ago, spanning Earth’s most recent period of repeated glaciations) sediments.
Denisova Cave is a key site for understanding the complex relationships between hominin groups that inhabited Eurasia in the Middle and Late Pleistocene epoch. Authors [see attached Douka et al. article] reported three direct dates for hominin fragments and obtained a mitochondrial DNA (mtDNA) sequence from one of them. Authors [by a Bayesian age-modeling approach that combines chronometric (radiocarbon, uranium series and optical ages), stratigraphic and genetic data to calculate probabilistically the age of the human fossils at the site] estimate the age of the oldest Denisovan fossil at the site as early as 195,000 years ago. All Neanderthal fossils — as well as Denisova fossil, and daughter fossil of the Neanderthal x Denisovan parents — were dated to between 80,000 and 140,000 years ago. The youngest Denisovan dates to 76,000–52,000 years ago.
Authors [see attached Jacobs et al. article] performed similar studies on this same Denisovan cave material independently — and reconstructed the environmental context of hominin occupation of the site from ~300,000 to 20,000 years ago. The first article is far more detailed than the second article. 🙂
DwN
Nature 31 Jan 2o19; 565: 594–599 & 640–644 [two articles] & Nature pp 571-572 [editorial] & Science 1 Feb 2o19; 363: p 438 {editorial]