DNA tests of bones add new species to human genus

Scientists have discovered remains of a mysterious new species of human being who lived alongside our ancestors 30,000 years ago in a cave in Siberia and named the cavemen "Denisovans," reported by Beijing Daily.

During the last Ice Age, Denisovans walked the Earth when modern humans were developing sophisticated stone tools, jewelry and art.

According to scientists, the cavemen were identified from DNA extracted from a tooth and finger bone, which belonged to a girl aged around 5 to 7, found in Denisova cave. The girl is nicknamed the X-Woman. Apart from the finger and tooth bone, scientists also found some ornaments and jewelry.

Provisional tests published earlier this year suggested she belonged to an entirely new species. Now a full DNA analysis has confirmed her place on the increasingly complex human family tree.

The discovery follows the controversial discovery of another so-called "new" species of 3-foot-tall human, referred to as "the Hobbit," on an Indonesian island in 2004.

However, many researchers have dismissed the Hobbit, claiming the bones came from a modern human with a growth disorder.

The Denisovans were physically different from the thickset Neanderthals and modern humans although they also walked upright two legs. The tooth resembles much older human ancestors, such as Homo erectus, pictured, which died out 1 million years ago, and scientists believe the Denisovans were similar in looks. They lived at a time when our ancestors and the Neanderthals were fishing and hunting, wearing jewelry, painting caves and making animal carvings.

A study also found extracts of Denisovan DNA in modern-day inhabitants of Melanesia, the islands to the north and east of Australia, including New Guinea. That suggests the Denisovans interbred with the ancestors of the Melanesians and may have been widespread in Asia.

The new species appears to have been a "sister group" to the Neanderthals and its discovery paints a complicated picture of human evolution and migration out of Africa, the cradle of mankind.

Scientists believe one group of early human ancestors left Africa between 300,000 and 400,000 years ago and quickly split up. One branch evolved into the Neanderthals who spread into Europe, while the other moved east and became Denisovans.

Around 70,000 years ago, there was another wave of migration when modern humans quit Africa. These were our ancestors, and they first encountered and interbred with Neanderthals, leaving traces of Neanderthal DNA in the genetic code of all non-Africans alive today.

One group of modern humans later came into contact with Denisovans, leaving traces of Denisovan DNA in the humans who settled in Melanesia.

David Derbyshire contributed to the story

By People's Daily Online