Unique remains give vital clues to man's origins and early travels, say experts.
Siberian archeologists work in the eastern part of Denisova Cave. Picture: Novosibirsk Institute of Archaelogy and Ethnography
Two separate cases this week show world scientists examining Siberia's deep past to understand the present. In one, the Royal Society in London was shown a genome analysis comparison between Neanderthals and the Denisovans, the latter from a girl's bone and teeth remains unearthed a cave in the Altai region of Siberia dating back around 50,000 years.
This points to a missing link, a 'missing human ancestor', say scientists, but also led to colourful headlines and stories on how 'ancient humans rampantly indulged in interspecies sex in a Lord Of The Rings-type world of different human groups'.
The other, based on publication in scientific journal Nature, is analysis of a 24,000 year old arm bone of a young Siberian boy which shows that the distant ancestors of native Americans looked more European than East Asian, a story revealed in The Siberian Times in October.
From this bone, scientists have sequenced the oldest-ever genome of a 'modern' human.
'Genetically, this individual had no east Asian resemblance but looked like Europeans and people from west Asia. But the thing that was really mind-blowing was that there were signatures you only see in today's Native Americans'. Picture: Russian State Hermitage museum
Disclosures about the first case were also foreshadowed in this story in The Siberian Times and are based on the discovery of early human remains in the Denisova Cave in the Altai Mountains. David Reich, of Harvard Medical School, said: 'Denisovans appear more distinct from modern humans than Neanderthals. He added, according to New Scientist: 'Denisovans harbour ancestry from an unknown archaic population, unrelated to Neanderthals.'
Mark Thomas, an evolutionary geneticist at University College London, claimed: 'What it begins to suggest is that we're looking at a Lord Of The Rings-type world - that there were many hominid populations'.
Scientists say they discovered evidence of Neanderthal and Denisovan viruses in modern DNA, indicated they originated in a common ancestor more than half a million years ago. Neanderthals co-existed man's ancestors in Europe for thousands of years, but belonged to a different human sub-species, becoming extinct around 30,000 years ago.
The revelation brought vivid coverage for Siberia in the international media, with the Herald-Sun in Australia explaining: 'Ancient humans rampantly indulged in inter-species sex in a Lord of the Rings-type world of different human groups, new DNA analysis has revealed. And our ancient bedfellows appear to have included a 'mystery human ancestor' which has not yet been identified.'
The second Siberian case has sparked a cascade of interest from around the world this week, but especially in North America because of its stunning implications for the origins of Native Americans.
'Denisovans appear more distinct from modern humans than Neanderthals; Denisovans harbour ancestry from an unknown archaic population, unrelated to Neanderthals'. Pictures from Denisova Cave: Novosibirsk Institute of Archaelogy and Ethnography
As The New York Times told its readers: 'The genome of a young boy buried at Malta near Lake Baikal in eastern Siberia some 24,000 years ago has turned out to hold two surprises for anthropologists.
'The first is that the boy's DNA matches that of Western Europeans, showing that during the last Ice Age people from Europe had reached farther east across Eurasia than previously supposed. Though none of the Mal'ta boy's skin or hair survive, his genes suggest he would have had brown hair, brown eyes and freckled skin.
'The second surprise is that his DNA also matches a large proportion - some 25 percent - of the DNA of living Native Americans. The first people to arrive in the Americas have long been assumed to have descended from Siberian populations related to East Asians. It now seems that they may be a mixture between the Western Europeans who had reached Siberia and an East Asian population.
'The Mal'ta boy was aged 3 to 4 and was buried under a stone slab wearing an ivory diadem, a bead necklace and a bird-shaped pendant. Elsewhere at the same site some 30 Venus figurines were found of the kind produced by the Upper Paleolithic cultures of Europe.
'The remains were excavated by Russian archaeologists over a 20-year period ending in 1958 and stored in museums in St. Petersburg.'
Entrance to Denisova Cave, and Anui river valley where scientific 'Denisova Cave' camp is based. Pictures: Novosibirsk Institute of Archaelogy and Ethnography
Eske Willerslev, of the University of Copenhagen, and his research team, wrote in journal Nature: 'We estimate that 14 to 38 percent of Native American ancestry may originate through gene flow from this ancient population.'
Willerslev stated: 'Genetically, this individual had no east Asian resemblance but looked like Europeans and people from west Asia. But the thing that was really mind-blowing was that there were signatures you only see in today's Native Americans.'
Dennis H. O'Rourke, an anthropologist at the University of Utah, an expert of ancient DNA and the North American Arctic, urged new research efforts in Siberia to provide a better context for Dr. Willerslev's reconstruction of early American origins.
'I think it's a very important and really interesting result, but it is from a single individual,' he said.
The Toronto Star raised another issue which scientists are seeking to resolve.
'The discovery does not tell researchers on which side of the Beringia land bridge the groups intermixed, nor when they came to this continent, questions Willerslev would like to resolve by sequencing the DNA of ancient individuals discovered in North America.'
The land bridge connected the extreme east of the Siberian land mass to present-day Alaska.
First exclusive pictures inside the grave of 'giant' warlord horseman who held sway in the 11th century but lost his left arm in his final battle.