Originally posted by Wulebgr
That's pretty much the hypothesis that is being tested through DNA work that has identified a hypothetical Eve, likely in Africa some two million years ago (there are some decimals around this "two"--1.8? or 2.3?--that I cannot recall with sufficient accuracy).
As I understand it, all humans have enough DNA in common to have come from a single mother. Fatherhood, as we know, is always speculative.
Mitocondircal DNA goes from mother to child, as sperms doesn't have it.
X-chromosome DNA goes from father to child, as the mother doesn't have any X's.
However, Mitocondrical DNA is more stable than X-chromosome, but that doesn't say that there is one and one only mother ancestor. It is as much likely to say that there is one and only one father ancestor, but it's harder to show.
But, there is no single mother, nor any single father. It's as stupid as saying that the humankind started with only two inidivuals, one male and one female. The fact is rather that one group of people were separated from another group. Our group survived. That's us.
There were no first man and woman. There were no Adam and Eve.