#oldest dna

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Oldest DNA ever found sheds new light on where humans came from

Science

Oldest DNA ever found sheds new light on where humans came from

Scientists have unravelled the oldest DNA ever retrieved from a Homo Sapiens bone, shedding light on modern humans' colonisation of the planet. A femur found by chance on the banks of a west Siberian river in 2008 is that of a man who died around 45,000 years ago, they said. Teased out of collagen in the ancient bone, the genome contains traces from Neanderthals - a cousin species who lived in Eurasia alongside Homo Sapiens before mysteriously disappearing.

While it is still possible that modern humans did traverse southern Asia before 60,000 years ago, those groups could not have made a significant contribution to the surviving modern populations outside of Africa, which contain evidence of interbreeding with Neanderthals.

Chris Stringer, a professor at Britain's Natural History Museum

Previous research has found that Neanderthals and Homo Sapiens interbred, leaving a tiny Neanderthal imprint of just about two per cent in humans today, except for Africans. The discovery has a bearing on the so-called "Out of Africa" scenario: The theory that Homo Sapiens evolved in East Africa around 200,000 years ago and then ventured out of the continent.

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Oldest DNA ever found sheds new light on where humans came from

Science

Oldest DNA ever found sheds new light on where humans came from

Scientists said Wednesday they had unravelled the oldest DNA ever retrieved from a Homo sapiens bone, a feat that sheds light on modern humans' colonisation of the planet. A femur found by chance on the banks of a west Siberian river in 2008 is that of a man who died around 45,000 years ago, they said. Teased out of collagen in the ancient bone, the genome contains traces from Neanderthals - a cousin species who lived in Eurasia alongside H. sapiens before mysteriously disappearing. Previous research has found that Neanderthals and H. sapiens interbred, leaving a tiny Neanderthal imprint of just about two per cent in humans today, except for Africans. The discovery has a bearing on the so-called "Out of Africa" scenario: the theory that H. sapiens evolved in East Africa around 200,000 years ago and then ventured out of the continent.

While it is still possible that modern humans did traverse southern Asia before 60,000 years ago, those groups could not have made a significant contribution to the surviving modern populations outside of Africa, which contain evidence of interbreeding with Neanderthals.

Chris Stringer, a professor at Britain's Natural History Museum

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Frozen History

                                          What may be the oldest fragments of the modern human genome found yet have now been revealed — DNA from the 7,000-year-old bones of two cavemen unearthed in Spain, researchers say.

These findings suggest the cavemen there were not the ancestors of the people found in the region today, investigators added.

Scientists have recently sequenced the genomes of our closest extinct relatives, the Neanderthals and the Denisovans. When it came to our lineage, the oldest modern human genomes recovered yet came from Ötzi the Iceman, a 5,300-year-old mummy found in the Alps in 1991. Researchers have salvaged DNA from even older human cells, but this comes from the mitochondria that generate energy for our bodies, and not from the nucleus where our chromosomes are housed. (Mitochondrial DNA is passed down only by mothers.)

Now researchers have rescued fragments of genomes from the remains of two cavemen unearthed in northern Spain.

The skeletons of two young adult males were discovered by chance in 2006 by cave explorers in a cavern high in the Cantabrian mountain range, whose main entrance is found at 4,920 feet (1,500 meters) altitude. Winters there are notably cold, which helped preserve the DNA in the bones.

These bones date back to the Mesolithic period, before agriculture spread to the Iberian Peninsula with Neolithic settlers from the Middle East. These cavemen were hunter-gatherers, judging by the ornament that one was found with of red-deer canines embroidered onto a cloth.

"There are many works that claim the Basques [of the Iberian Peninsula] could be descendants from Mesolithics that became isolated in the Basque country," Lalueza-Fox said. "We found the modern Basques are genetically not related to these two individuals."

The scientists also recovered the complete mitochondrial DNA of one of these cavemen. This revealed that European populations during the Mesolithic were very uniform genetically.

"Despite their geographical distance, individuals from the regions corresponding to the current England, Germany, Lithuania, Poland and Spain shared the same mitochondrial lineage," Lalueza-Fox said. "These hunters-gatherers shared nomadic habits and had a common origin."

The researchers now aim to complete the genomes of both cavemen. Such data could help "explore genes that have been modified with the arrival of the Neolithic in the European populations," Lalueza-Fox said.

The scientists detailed their findings online today (June 28) in the journal Current Biology.