According to a research reported in the European Journal of Human Genetics, Adam who is our most recent ancestor had lived on the Earth for about 208,300 years ago. Researchers have used easier biological models which shows that Adam or Y- chromosome Adam is 8,300 years older than scientists originally believed to be. They have put Y-chromosomal Adam within the time frame of the Mitochondrial Eve.
Modern humans have emerged in Africa for over 200,000 years ago, that we can say with some confidence.
But the findings have contradicted with the paper which was published in the American Journal of Human Genetics in February 2013 that claimed the human Y chromosome originated in a different species through interbreeding who dated Adam who was thought to be twice as old.
Their hypothesis have created a sort of space-time paradox but the most ancient individual belonging to Homo sapiens species has not yet been born. If we take the results from other studies seriously then 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.
It is certain that modern humans did not interbreed with hominins living over 500,000 years ago. It is 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.
The question to what extend did our humans for bearers interbreed with their closest relatives is one of the hottest questions in anthropology that remains open.