To The discover why Neanderthals are so closely related to humans outside of Africa, scientists from Harvard and the Max Planck Institute of estimates dating when Neanderthals and modern humans in Europe last share a common ancestor. Research published in the journal PLoS Genetics, the thrust of the historical context for the cross-breeding. Research shows that modern humans may have interbred with Neanderthals soon after they spread out of Africa.Neanderthals were in Europe when modern humans spread out of Africa. Both coexisted for thousands of years before Neanderthals became extinct about 30,000 years ago.
When the Neanderthal genome sequenced in 2010, it is revealed that humans outside Africa has a little more Neanderthal genetic variants than Africans. One of the scenarios that could explain this observation is that modern humans have been mixed with the Neanderthals as they come out of Africa. Alternatively, but more complex, is the scenario that the population in Africa is the ancestor to Neanderthals and modern humans.
Dr. Sriram Sankararaman colleagues measuring range of DNA fragments that are similar to the genome of the Neanderthals in Europe. Because recombination between two chromosomes when the egg and sperm are formed reduce the size of a few pieces of each generation, Neanderthal-related pieces will be smaller.
The research team estimates that Neanderthals and modern humans last time swapping genes between 37,000 and 86,000 years ago, shortly after the emergence of modern humans outside of Africa, but the possibilities before they begin to spread across Eurasia.
The researchers found that the likelihood of sexual intercourse took place in the Middle East.
They wrote: "Genetic analysis by itself does not indicate where possible gene flow. However, the calendar in conjunction with archaeological evidence suggests that the two populations are likely to meet somewhere in the western part of Eurasia.
"An interesting hypothesis is in the Middle East, where archaeological evidence and the fossil suggests that modern humans appear before 100,000 years ago."
