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Possible new extinct human species identified

March 25, 2010
Courtesy Nature Publishing Group
and World Science staff

A pre­vi­ously un­known line­age of hu­mans has been iden­ti­fied based on genes ex­tracted from a bit of bone found in Si­be­ria, sci­en­tists say.

The find­ing may rep­re­sent a new spe­cies that lived along­side Ne­an­der­thal peo­ple and an­a­tom­ic­ally “mod­ern” hu­mans in that re­gion, ac­cord­ing to the re­search­ers.

Denisova cave from the out­side. (Cred­it: Bence Vio­la)


“I at first did­n’t be­lieve” that the re­sult could be pos­si­ble, said one of the re­search­ers in­volved with the find­ing, Svante Pääbo of the Max Planck In­sti­tute for Ev­o­lu­tion­ary An­thro­po­l­ogy, Leip­zig, Ger­ma­ny. How­ev­er, Pääbo said, ge­net­ic test re­sults showed “it’s some new crea­ture that has not been on our ra­dar screen so far.” The find­ings are pub­lished in the March 25 is­sue of the re­search jour­nal Na­ture.

The con­clus­ions were based on the se­quenc­ing, or de­cod­ing, of the or­gan­is­m’s “mi­to­chon­drial ge­nome,” that is, DNA from a cel­lu­lar struc­tures called the mi­to­chon­dria. 

Mi­to­chon­chon­drial DNA is not in­her­it­ed the same way as the rest of an an­i­mal’s DNA, but rath­er is passed down only from the moth­er. Be­cause un­like oth­er DNA it re­mains re­la­tive­ly un­changed when passed down through genera­t­ions, it plays an im­por­tant role in an­ces­try stud­ies, in par­tic­u­lar in de­ter­min­ing an or­gan­is­m’s moth­er-line an­ces­try.

The ge­net­ic se­quenc­ing point­ed to a pre­vi­ously un­known ho­minin, or ex­tinct mem­ber of the hu­man line­age, who lived in the Al­tai moun­tains of south­ern Si­be­ria be­tween 48,000 and 30,000 years ago, said the re­search­ers.

The inves­tigat­ing team, which in­clud­ed al­so re­search­ers from the Un­ited States, Aus­tria and Rus­sia, se­quenced genes from a ti­ny piece of pinky fin­ger bone found in Denisova cave in the Al­tai Moun­tains. They com­pared the mi­to­chon­drial ge­nome with that of mod­ern hu­mans and Ne­an­der­thals. 

The anal­y­sis in­di­cat­ed that the crea­ture shared a com­mon fe­male or “mi­to­chon­drial” an­ces­tor with mod­ern hu­man and Ne­an­der­thals about a mil­lion years ago, the sci­en­tists said. That’s about twice as old as what is be­lieved to be the most re­cent com­mon mi­to­chon­drial an­ces­tor of mod­ern hu­mans and Ne­an­der­thals. Ne­an­der­thals were a stocky, now ex­tinct sub­group of our spe­cies, Ho­mo sapi­ens, who lived in Eu­rope and parts of Asia from around 100,000 to 30,000 years ago.

The age of the fos­sil and the lay­ers of earth in which they turned up al­so sug­gest “the Deni­sova ho­minin lived close in time and space with Ne­an­der­thals as well as with mod­ern hu­mans,” the re­search­ers wrote.

Al­though re­search­ers said they lacked de­fin­i­tive enough in­forma­t­ion to de­clare the fos­sil a new spe­cies, they said it al­so likely rep­re­sented a sep­a­rate migra­t­ion out of Af­ri­ca from mod­ern hu­mans and Ne­an­der­thals, both of whom are thought to have orig­i­nat­ed in that con­ti­nent. The in­ves­ti­ga­tors al­so said they have no in­forma­t­ion yet that could serve to phys­ic­ally de­scribe any un­usu­al char­ac­ter­is­tics that the new­found hu­man rela­tive might have pos­sessed.


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A previously unknown lineage of humans has been identified based on genes extracted from a bit of bone found in Siberia, scientists say. The finding may represent a new species that lived alongside Neanderthal people and anatomically “modern” humans in that region, according to the researchers. “I at first didn’t believe” that the result could be possible, said one of the researchers involved with the finding, Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. However, Pääbo said, genetic test results showed “it’s some new creature that has not been on our radar screen so far.” The findings are published in the March 25 issue of the research journal Nature. The findings were based on the sequencing, or decoding, of the organism’s “mitochondrial genome,” that is, DNA from a cellular structures called the mitochondria. Mitochondrial DNA is not inherited the same was as the rest of an animal’s DNA, but rather is passed down only through the mother. Because unlike other DNA it remains more of less unchanged when passed down through generations, it plays an important role in ancestry studies, in particular in determining an organism’s mother-line ancestry. The genetic sequency pointed to a previously unknown hominin, or extinct member of the human lineage, who lived in the Altai mountains southern Siberia between 48,000 and 30,000 years ago, said the researchers. The group, which included also researchers from the United States, Austria and Russia, sequenced genes from a tiny piece of pinky finger bone found in Denisova cave in the Altai Mountains. They compared the mitochondrial genome with that of modern humans and Neanderthals. The analysis indicated that the creature shared a common female or “mitochondrial” ancestor with modern human and Neanderthals about a million years ago, the scientists said. That’s about twice as old as what is believed to be the most recent common mitochondrial ancestor of modern humans and Neanderthals. Neanderthals were a stocky, now extinct subgroup of our species, Homo sapiens who lived in Europe and the area around the Mediterranean from 100,000 to 30,000 years ago. The age of the fossil and the layers of earth in which they turned up also suggest “the Denisova hominin lived close in time and space with Neanderthals as well as with modern humans” in southern Siberia, the researchers wrote. Although researchers said they did not have definitive enough information to declare the fossil a new species, they said it also likely represented a separate migration out of Africa from modern humans and Neanderthals, both of whom are thought to have originated in that continent. The investigators also said they have no information yet that could serve to physically describe any unusual characteristics that the newfound human ancestor might have possessed.