The period some 30,000 – 50,000 years ago is getting positively crowded with different branches of humans. The direct ancestors of modern humans lived and interbred not only with Neanderthals and Denisovans but also apparently with still another, as yet unknown, branch of humans.
Nature: New genome sequences from two extinct human relatives suggest that these ‘archaic’ groups bred with humans and with each other more extensively than was previously known.
The ancient genomes, one from a Neanderthal and one from a different archaic human group, the Denisovans, were presented on 18 November at a meeting at the Royal Society in London. They suggest that interbreeding went on between the members of several ancient human-like groups living in Europe and Asia more than 30,000 years ago, including an as-yet unknown human ancestor from Asia. ..
… All humans whose ancestry originates outside of Africa owe about 2% of their genome to Neanderthals; and certain populations living in Oceania, such as Papua New Guineans and Australian Aboriginals, got about 4% of their DNA from interbreeding between their ancestors and Denisovans, who are named after the cave in Siberia’s Altai Mountains where they were discovered. The cave contains remains deposited there between 30,000 and 50,000 years ago.
Those conclusions however were based on low-quality genome sequences, riddled with errors and full of gaps, David Reich, an evolutionary geneticist at Harvard Medical School in Boston, Massachusetts said at the meeting. His team, in collaboration with Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have now produced much more complete versions of the Denisovan and Neanderthal genomes — matching the quality of contemporary human genomes. The high-quality Denisovan genome data and new Neanderthal genome both come from bones recovered from Denisova Cave.
The new Denisovan genome indicates that this enigmatic population got around: Reich said at the meeting that they interbred with Neanderthals and with the ancestors of human populations that now live in China and other parts of East Asia, in addition to Oceanic populations, as his team previously reported. Most surprisingly, Reich said, the new genomes indicate that Denisovans interbred with another extinct population of archaic humans that lived in Asia more than 30,000 years ago, which is neither human nor Neanderthal.
It would seem that when the world was still in the grip of an ice age 30,000 – 50,000 years ago, the reality of human history was not so far away from Tolkien’s Middle Earth. Ancient history but it was only 1,500 – 2,500 generations ago. Middle Earth was where men could breed with elves and hobbits were an off-shoot of men. The Druedain were also off-shoots of men and some – if not all – orcs were deliberately bred from elves while all trolls and dragons were artificially bred.
From the J.R.R. Tolkien Encyclopedia: Scholarship and Critical Assessment
from The biology of Middle Earth – JRR Tolkien Encyclopedia
Tags: Altai Mountains, David Reich, Denisova Cave, Denisova hominin, JRR Tolkien, Middle Earth, Neanderthal, Svante Pääbo
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