4 December 2013
The discovery of DNA in a 400,000-year-old human thigh bone will open up a new frontier in the study of our ancestors.That's the verdict of experts in human evolution on an analysis in Nature journal of the oldest human genetic material ever sequenced.The femur comes from the famed "Pit of Bones" site in Spain, which gave up the remains of at least 28 ancient people.But the results are perplexing, raising more questions than answers about our increasingly complex family tree.The early human remains from the cave site near the northern Spanish city of Burgos have been painstakingly excavated and pieced together over the course of more than two decades by palaeontologists. It has yielded one of the richest assemblages of human bones from this stage of human evolution, in a time called the Middle Pleistocene.To access the pit, scientists must crawl for hundreds of metres through narrow cave tunnels and rope down through the dark. The bodies were probably deposited there deliberately - their causes of death unknown.The fossils carry many traits typical of Neanderthals, and either belong to an ancestral species known as Homo heidelbergensis - or, as the British palaeoanthropologist Chris Stringer suggests - are early representatives of the Neanderthal lineage.DNA's tendency to break down over time means it has not previously been possible to study the genetics of such ancient members of the human family.But the recent pace of progress in sequencing technology has astonished many scientists: "Years ago, geneticists said they wouldn't be able to find DNA that was older than 60,000 years old," said co-author Jose Bermudez de Castro, and a member of the team that excavated the Pit of Bones fossils."Of course, that wasn't true. The techniques have advanced hugely."
Another look into our Ancestors by DNA.