Y-chromosomal Adam

Because the Y chromosome in human males is only passed down through males, it is possible to trace lineage from son-to-father backwards in time. Accounting for minor genetic mutations over time, males can find common ancestors (which is how scientists were able to determine that 0.5% of all human males on Earth, and 8% of all Asian men, are descended from prolific lover/rapist/rapist developer Genghis Khan)^[1].Y-chromosomal Adam is the most recent male human who all living male humans are patrilinearly descended from. He is the male counterpart to Mitochondrial Eve.

Y-chromosomal Adam was a real person, but is named after Adam from Book of Genesis in the Old Testament of the Bible. In Christian mythology, Y-chromosomal Adam would actually be Noah; in reality, scientists don't know who Y-chromosomal Adam actually was (and the odds are good that he wasn't the named Adam or Noah). Unlike Adam from the Bible (and very much like Noah), Y-chromosomal Adam was not the only male on Earth; instead, all of his male contemporaries failed to produce exclusively male lineages that continue to live today.

It is also understood that Y-chromosomal Adam and Mitochondrial Eve, unlike Biblical Adam and Eve, need not have lived together in the same location or period of time, and were almost certainly not mates.

[edit]How long ago did he live?

Calculations by the geneticist Spencer Wells have shown that this man lived around 60,000 years ago.^[2] Other calculations put the time of Y-Adam as far back as 142,000 years ago^[3], over twice that of Wells' date.

In 2013, a recently-deceased man was found whose Y-chromosome DNA did not match any of the others previously acquired. This new information would now put the estimate for Y-chromosomal Adam to have been alive 340,000 years ago.^[4]. However, this value was derived from a low estimate of the mutation rate^[5][6]. More recent estimates of the mutation rate, based on ancient DNA data^[7], suggest that the date should be ~20% younger.