Y-chromosomal Adam

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In human genetics, Y-chromosomal Adam (Y-mrca) is the patrilineal human most recent common ancestor (mrca) from whom all Y chromosomes in living men are descended. Y-chromosomal Adam is thus the male counterpart of Mitochondrial Eve (the mt-mrca), the matrilinear human most recent common ancestor, from whom all mitochondrial DNA in living humans is descended.

1 Time frame
2 Naming
3 References
4 See also
5 External links

[edit] Time frame

Y-chromosomal Adam probably lived around 50,000 years ago, judging from molecular clock and genetic marker studies. While their descendants certainly became close intimates, Y-chromosomal Adam and mitochondrial Eve are separated by at least 50,000 years, or many hundred generations.

The more recent age of the Y-mrca compared to the mt-mrca corresponds to a larger statistical dispersion of the probability distribution for a paleolithic man to have living descendants compared to that of a paleolithic woman. While fertile women had more or less equally distributed chances of giving birth to a certain number of fertile descendants, chances for fertile men varied more widely, with some fathering no children and others fathering many, with multiple women.

Y-chromosomal Adam is not the same individual at all points in human history; the Y-mrca of all humans alive today is different from the one for humans alive at some point in the remote past or future: as male lines die out, a more recent individual becomes the new Y-mrca. In times of rapid population growth, patrilinear lines are less likely to die out than during a population bottleneck.

[edit] Naming

Y-chromosomal Adam is named after the "Adam" of the Genesis creation story as a metaphor only, and is not considered to be the first human.

The name incorrectly implies that Y-chromosomal Adam was the only living male of his time; he was not. Many men alive at the same time as Y-chromosomal Adam have descendants alive today. However, only Y-chromosomal Adam produced an unbroken line of male descendants carrying his Y chromosome (Y-DNA) that persists today.

[edit] References

"Modern Men Trace Ancestry to African Migrants", A Gibbons, Volume 292, Number 5519, Issue of 11 May 2001, pp. 1051-1052.
"African Origin of Modern Humans in East Asia: A Tale of 12,000 Y Chromosomes", Yuehai Ke et al, Science 2001 292: 1151-1153
Fazale Rana and Ross, Hugh, Who Was Adam: A Creation Model Approach to the Origin of Man, 2005, ISBN 1-57683-577-4