As a result, between 1pc [percent] and 4pc of the DNA of non-African people alive today is Neanderthal, according to the research. The discovery emerged from the first attempt to map the complete Neanderthal genetic code, or genome. It more or less settles a long-standing academic debate over interbreeding between separate branches of the human family tree. Evidence in the past has pointed both ways, for and against modern humans and Neanderthals mixing their genes. ... Prof Svante Paabo, of the Institute for Evolutionary Anthropology in Leipzig, Germany, said: "Those of us who live outside Africa carry a little Neanderthal DNA in us."
I will have a thorough write-up when I get a hold of the paper, which should be soon. As I said, this is a story of genomics, not just genetics. 1-4% is not trivial. The Daily Telegraph has more:
They were surprised to find that Neanderthals were more closely related to modern humans from outside Africa than to Africans. Even more mysteriously, the relationship extended to people from eastern Asia and the western Pacific - even though no Neanderthal remains have been found outside Europe and western Asia. The most likely explanation is that Neanderthals and Homo sapiens interbred before early modern humans struck out east, taking traces of Neanderthal with them in their genes. Professor Svante Paabo, director of evolutionary genetics at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who led the international project, said: "Since we see this pattern in all people outside Africa, not just the region where Neanderthals existed, we speculate that this happened in some population of modern humans that then became the ancestors of all present-day non-Africans. "The most plausible region is in the Middle East, where the first modern humans appeared before 100,000 years ago and where there were Neanderthals until at least 60,000 years ago. "Modern humans that came out of Africa to colonise the rest of the world had to pass through that region." ... Several genes were discovered that differed between Neanderthals and Homo sapiens and may have played important roles in the evolution of modern humans. They included genes involved in mental functions, metabolism, and development of the skull, collar bone and rib cage.
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