And Adam knew Eve his wife; and she conceived....
Genesis 4:1
"Sanford and Carter have also analyzed the Y chromosomes of modern men which they found to be only about 300 mutations on average 
different than the consensus sequence of a Y chromosome Adam.
As a result, they state:“Even if we assume a normal mutation rate for the Y chromosome (about 1 mutation per chromosome per generation), we would only need 300 generations (about six thousand years), to get 300 mutations.”
As with their previous mtDNA work, this is the most straightforward application of the DNA clock concept and provides data perfectly in accord with a biblical timeframe for the origins of man." CMI