A new study may have correctly placed "Adam" in humanity’s evolutionary history.
According to a new study, published in the European Journal of Human Genetics, the most recent common male ancestor to humans existed 209,000 years ago – 9,000 years earlier than scientists had previously thought. The findings place the earliest female ancestor, "Eve," within the same timeframe as her male counterpart.
"We can say with some certainty that modern humans emerged in Africa a little over 200,000 years ago," Eran Elhaik of the University of Sheffield said in a statement.
The latest findings contradict a recent study that suggested Adam was twice as old as Eve on the basis that the Y chromosome originated in a different species through interbreeding. They also debunked a separate study that said the discovery of the Y chromosome predated humanity.
"We have shown that the University of Arizona study lacks any scientific merit. In fact, their hypothesis creates a sort of 'space-time paradox,' whereby the most ancient individual belonging to Homo sapiens species has not yet been born,” Elhaik said. "Think of the movie 'Back to the Future,' when Marty was worried that his parents would not meet and as a result he wouldn’t be born -- it’s the same idea.”
The latest research used conventional biological models to date the most common male ancestor. The research team calculated the age of the Y chromosome by multiplying data on the average age fathers have their first child with the number of mutations they found. This number was then divided by the mutation rate of the Y chromosome.
“Of course, we can manipulate each one of these variables to make a finding look younger or older,” Elhaik told The Daily Mail. “In our paper, we showed the previous study manipulated all these variables to predate the Y chromosome.”
While the study challenges other conclusions, it raises more questions concerning the behavior of ancient humans.
"It is obvious that modern humans did not interbreed with hominins living over 500,000 years ago. It is also clear that there was no single 'Adam' and 'Eve' but rather groups of 'Adams' and 'Eves' living side by side and wandering together in our world,” Elhaik said. “The question to what extent did our human forbearers interbreed with their closest relatives is one of the hottest questions in anthropology that remains open.”