Scientists have reconstructed the entire genome of an extinct type of human from a 30,000-year-old finger bone, and made it available on the internet.
The discovery of the finger in Denisova Cave in southern Siberia was announced in 2010, and a draft version of the genome created. This showed that this individual came from a previously unknown group of extinct humans that have become known as Denisovans.
Together with the Neanderthals, Denisovans are the closest extinct relatives of currently living humans. It appears that human occupation at the site started up to 280,000 years ago, while the finger bone was found in a layer which has been dated to between 50,000 and 30,000 years ago.
Now, the Max Planck Institute for Evolutionary Anthropology team has developed new techniques which have allowed them to sequence every position in the Denisovan genome about 30 times over, using DNA extracted from less than 10 milligrams of the finger bone.
This allows even the small differences between the copies of genes that this individual inherited from its mother and father to be distinguished.
“The genome is of very high quality,” says Matthias Meyer, who developed the new sequencing techniques.
“We cover all non-repetitive DNA sequences in the Denisovan genome so many times that it has fewer errors than most genomes from present-day humans that have been determined to date.”
It’s the first high-coverage, complete genome sequence of an archaic human group. It’s hoped that biologists will be able to use the genome to discover genetic changes that were important for the development of modern human culture and technology, and which enabled modern humans to leave Africa and rapidly spread around the world. It’s also expected to reveal new aspects of the history of Denisovans and Neanderthals.
The genome is available here.