"Adam", our most common male ancestor, walked the earth 209,000 years ago, 9,000 years earlier than previously believed and within the time frame of his other half "Eve", the genetic maternal ancestor of mankind, according to a new paper. 

Writing in the European Journal of Human Genetics, Dr. Eran Elhaik from the University of Sheffield and colleagues also take the opportunity to blow up some other research, such as the discovery that the Y chromosome predated humanity (the A00 lineage) and originated in a different species through interbreeding, which dates "Adam" to be much older. 

Going after the work of others is not new to Elhaik. Earlier this year he also claimed to debunk Michael Hammer's previous work on the unity of the Jewish genome and together with co-author Dr. Dan Graur they refuted the proclamations made by the ENCODE project on junk DNA. 

"We can say with some certainty that modern humans emerged in Africa a little over 200,000 years ago," said Elhaik. "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.

"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. If we take the numerical results from previous studies seriously we can conclude that the past may be altered by the mother of 'Adam' deciding not to conceive him in the future, thus, bringing a retroactive end to our species.

Critics of biology think that scientists are some cabal that circle the wagons around each other. That is not the case, they love to try and trip each other up. Nothing typifies the conservative nature of science more than peer review.

"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 question to what extend did our humans forbearers interbreed with their closest relatives is one of the hottest questions in anthropology that remains open."