Wednesday, 14 March 2012

A New Species Of Human

A 11,500 to 14,500 year old skull from the Red Deer Cave
In 2003, a 38,000 year old skeleton of a mysterious hominid was unearthed in the Liang Bua Cave on the island of Flores. At first it was thought to be from an ape, but analysis revealed that it was in fact from a fully grown, but tiny species of human which was named Homo floresiensis and given the nickname 'the hobbit.' In 2008, a single 41,000 finger bone was found in the Denisova Cave in the Altai mountains in Russia.

Genetic analysis showed that it came from another completely unknown species of human. While they have not yet been given a proper scientific name, the creatures are known as the Denisova hominids. These two discoveries caused a great stir in the palaeontological and anthropological world as they showed that there were still species of undiscovered humans which had once lived on the planet alongside our species and the Neanderthals.

An artist's impression of the Red Deer Cave people
Palaeontologists excavating in Southern China believe that they may have found a third new species. The 11,500 to 14,500 year old remains were uncovered in the Red Deer Caves near the city of Mengzi in the Yunnan Province alongside a further skeleton discovered at Longlin in the neighbouring Guangxi province. It was immediately apparent that they were something different. Computed tomography scans of the cranium showed that they had modern frontal lobes but archaic anterior lobes and large molars.

All in all the creatures seemed like a throwback to the early humans such as Homo habilis, with their chunky and archaic features. 'We're trying to be very careful at this stage about definitely classifying them' said study co-leader Darren Curnoe from the University of New South Wales, Australia. As a result the remains have simply been named the Red Deer Cave people. As we still do not have a current definition for our own species, it makes naming new humans difficult.

The team have put forward three different hypotheses to explain their origins. The first is that they were simply a form of archaic Homo sapiens which migrated out of Africa very early and lived separate from other human populations before dying out. The second scenario states that they are simply a subspecies of ours which evolved in Asia and lived alongside our own kind until very recently. Their final theory is that the Red Deer Cave people are a hybrid of archaic and modern humans.

'The other option is that they evolved these more primitive features independently because of genetic drift or isolation, or in a response to an environmental pressure such as climate' said Dr Curnoe. What makes them interesting is where they fit into the picture of Chinese anthropology. Between 11,000 and 14,000 years ago, modern humans in China were making pottery and developing the first forms of agriculture. Stone tools found alongside the Red Deer Cave remains may help to answer this.

The team are currently attempting to extract DNA from the fossils and perform genomic analysis to determine their position on the human family tree. This, apart from determining whether they are a new species or not, may show if they inter-bred with our species or even the Denisovans and how interaction with them may have shaped our species both culturally and genetically.