Islanders in the Pacific Ocean could be might be taking traces of a long lost human species locked up in their DNA. Today, modern people inherit a small chunk of our genes from Neanderthals, together with proof that some of us take the genetic fires of a lesser known sister group, called the Denisovans.
But genetic analysis of folks living in modern Melanesia indicates that they carry traces of a thirdparty, as yet unidentified ancient relative different from others.
The most recent research, presented at a meeting of the American Society for Human Genetics in Vancouver, bolsters previous findings that there might be an additional strand to the story of contemporary people, with multiple groups of ancient human interbreeding.
Genetic evaluation of Europeans, Asians and others using non-African descent hints that early humans interbred with Neanderthals. Some groups inherited as much as four per cent of the DNA from these types of extinct human cousins.
A single finger bone and a few teeth found in a cave in Russia showed another branch of the family tree, the Denisovans, also abandoned their hereditary calling card from contemporary humans, accounting for up to four per cent of people’s DNA at Melanesia.
ANOTHER TWIST IN THE TALE OF HUMAN EVOLUTION?
The island peoples from the Pacific Ocean have a different genetic ancestry. Genetic analysis shows their ancestors bred with two groups of early people, both the Neanderthals and Denisovans. This connection is produced by comparing samples of islanders with DNA sequences extracted from remains of these early human species.
But studying the rate of genetic blending in Melanesia showed a high percentage of other extinct ancestry that was unaccounted for. Researchers consider this genetic evidence of a third unknown group of species which predated the Denisovans by thousands and thousands of years.
The tantalising genetic evidence supplies a hint of some other branch of the human family tree. But unlike Neanderthals and Denisovans, there aren’t any known physical stays to compare it with. This unidentified third group could add yet another twist in the story of human development.
Now, the most recent number crunching has shown another genetic twist in the narrative of modern people.
Ryan Bohlender, a geneticist at the University of Texas, and colleagues looked at the rate of genetic blending which would account for what is seen in contemporary Melanisians and found that something did not add up.
As expected, their analysis found the hereditary calling cards of Denisovans and Neanderthals, but in addition, it revealed a high proportion of other extinct ancestry unaccounted for.
To describe this mystery DNA, the group consider that early Melanesians has to have bred using a third set of hominids.
By working out the amount of DNA shared with Neanderthals and Denisovans, they calculated this third extinct human species probably branched off from their common ancestor 440,000 decades ago.
Past studies have revealed that ancient Melanesians’ trysts using Denisovans might have helped them to adapt to new environments and spread throughout the Pacific and to Australia.
One of the Denisovan genes are those which boost resilience to viruses and provide metabolic benefits, including raising blood sugar levels and breaking down fats.
Tracing the hereditary lineage has revealed that modern humans interbred with Neanderthals a number of occasions and Denisovans at least once, before both of these human cousins died out.
Click to WATCH: Scientists Shocked As They Find Melanesians Carry DNA Of An Unknown “Human” Species
WHO WERE THE DENISOVANS?
The Denisovans are an extinct species of human that appear to have lived in Siberia and even down so much as southeast Asia.
Although remains of those mysterious early people have only been found in one site – the Denisova Cave in the Altai Mountains in Siberia, DNA analysis has shown they were prevalent.
DNA from these early humans has been found in the genomes of modern people over a wide region of Asia, suggesting they once covered a huge variety.
They’re thought to have been a sister species of the Neanderthals, who lived in western Asia and Europe at roughly the exact same time.
The two species seem to have separated from a frequent ancestor around 200,000 decades ago, while they split from the modern human Homo sapien lineage about 600,000 decades ago.
Bone and ivory beads found from the Denisova Cave were found in precisely the same sediment layers as the Denisovan fossils, resulting in suggestions they had complex tools and jewellery.
‘But, direct relationship work by the Oxford Radiocarbon Unit reported in the ESHE meeting indicates the Denisovan fossil is over 50,000 years old, whereas the oldest ‘advanced’ artefacts are approximately 45,000 years old, a date that matches the appearance of modern humans elsewhere in Siberia.’