Neanderthals 'bred with early humans'
Scientists discover genes from primitive species in 21st-century DNA
Neanderthal man interbred with the first anatomically modern humans to migrate out of Africa, according to a pioneering study showing that there was a flow of genetic material between early Homo sapiens and our extinct cousins.
Scientists had dismissed the idea that Neanderthalers could have had children with our early ancestors, but a study of the Neanderthal genome, derived from analysing 40,000-year-old fossilised bones, has produced the most convincing evidence to date of limited interbreeding.
The findings suggest that although there was "gene flow" from Neanderthalers to H. sapiens, there was no evidence of any genetic exchange in the opposite direction – suggesting that the resulting children were raised by modern humans. Interbreeding was more likely between Neanderthalers and H. sapiens women.
Although it is known that the territories of the Neanderthalers, which extended across Europe and central Asia, overlapped with those of modern humans, there was little evidence that they interacted with one another, despite living cheek by jowl for thousands of years.
Scientists said they were surprised at their analysis of the draft Neanderthal genome, which comprises some three billion "letters" of the genetic code and was painstakingly built up from small fragments of DNA extracted from the bones of various Neanderthal specimens excavated in Croatia, Spain, Russia and Germany.
When they compared the Neanderthal genome to that of five modern-day humans, the scientists found small fragments of Neanderthal sequences in all non-Africans, even in a person from Papua New Guinea, where Neanderthalers had never lived. This suggests the interbreeding occurred soon after the initial migration of H. sapiens out of Africa between 50,000 and 80,000 years ago.
"We can now say that, in all probability, there was gene flow from Neanderthals to modern humans," said Dr Ed Green of the University of California, Santa Cruz, the lead author of the study, which was published in the journal Science.
"The scenario is not what most people had envisaged. We found the genetic signal of Neanderthals in all the non-African genomes, meaning the admixture occurred early on, probably in the Middle East, and is shared with all descendants of the early humans who migrated out of Africa," Dr Green said.
Dr David Reich of Harvard Medical School in Boston, Massachusetts said that other possible explanations for the results have been largely dismissed and that they appear to resolve the controversy over whether there was any interbreeding between the two species of humans.
"The main finding is that there was gene flow from Neanderthals into the ancestors of all modern non-Africans. We do not find any evidence at all of gene flow into sub-Saharan Africans. We also do not find any evidence of gene flow in the reverse direction into Neanderthals," Dr Reich said.
"The proportion of Neanderthal ancestry in non-Africans today is between 1 and 4 per cent so it's a small but very real proportion of ancestry in non-Africans today," he added.
Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany had previously dismissed the idea of interbreeding when he analysed Neanderthal mitochondrial DNA, which is maternally inherited from mothers to offspring.
He said the findings on the nuclear DNA of Neanderthalers had surprised him because he was biased into believing that interbreeding did not occur. However, the work on mitochondrial DNA hints at the idea that the interbreeding was between Neanderthalers and H. sapiens women, he said.
- 1 Sofyen Belamouadden murder: The inside story of a crime that horrified Britain
- 2 How to turn off/stop 'seen by' on Facebook: Disable it to make your chats seem less passive aggressive
- 3 Company breaks open Apple Watch to discover what it says is 'planned obsolescence'
- 4 'We're not heroes, just tourists': Swedish police officers on holiday stop vicious assault on New York subway
- 5 Buckingham Palace guard who attacked passers-by in 'most most violent piece of CCTV footage' police officer had seen walks free
Top 20 misconceptions people believe are true
Sofyen Belamouadden murder: The inside story of a crime that horrified Britain
'We're not heroes, just tourists': Swedish police officers on holiday stop vicious assault on New York subway
Nepal earthquake: More than 1,100 killed across four countries and in Mount Everest avalanche
Australian student Tommy Connolly, 23, adopts his pregnant, homeless 17-year-old cousin to give her a chance at 'a better life'
The sickening truth about food banks that the Tories don't want you to know
Migrant boat disaster: Ukip candidate mocks victims in sickening Twitter post
Nigel Farage wants the BBC to stop making programmes like Doctor Who, Strictly Come Dancing, and Top Gear
Global warming: Scientists say temperatures could rise by 6C by 2100 and call for action ahead of UN meeting in Paris
Rupert Murdoch berated Sun journalists for not doing enough to attack Ed Miliband and stop him winning the general election
General Election 2015: Britain would become a 'communist dictatorship' under Ed Miliband and Nicola Sturgeon, claims wife of Michael Gove
£22000 - £40000 per annum: Recruitment Genius: This company is part of a Group...
£16000 - £18000 per annum: Recruitment Genius: Are you a a young, dynamic pers...
Voluntary: Cancer Research UK: We’re looking for someone to support our award ...
£70000 - £90000 per annum + bonus + car allowance + benefits: Ashdown Group: H...