By analyzing the DNA of many different people, it is possible to learn the
approximate date and location of their common ancestor. Scientists have
done this with mitochondrial DNA (mtDNA) from diverse human populations.
Since mtDNA is inherited only from the mother, this traces humanity back
to a common "mitochondrial Eve." Scientists say she came from Africa
about 200,000 years ago (Cann et al. 1987), but the age may be mistaken,
and Asia and Europe have also been suggested as the location, consistent
with an origin from near Mt. Ararat. Mitochondrial Eve is consistent with
Biblical Eve.
The "mitochondrial Eve," to which this claim refers, is the most recent
common female ancestor, not the original female ancestor. There would
have been other humans living earlier and at the same time. The mtDNA
lineages of other women contemporary with her eventually died out.
Mitochondrial Eve was merely the youngest common ancestor of all
today's mtDNA. She may not even have been human.
The same principles find that the most recent human male common
ancestor ("Y-chromosome Adam") lived an estimated 84,000 years after
the "mitochondrial Eve" and also came from Africa (Hawkes 2000;
Underhill et al. 2000; Yuehai et al. 2001).
The results assume negligible paternal inheritance of mitochondrial
DNA, but that assumption has been called into question. Male mtDNA
resides in the tail of the sperm; the tail usually does not enter the
egg that the sperm fertilizes, but rarely a little bit does. It is
also possible that there is some recombination of mtDNA between
lineages, which would also affect the results (Awadalla et al. 1999;
Eyre-Walker et al. 1999). But these challenges have themselves been
questioned (Kivisild et al. 2000).
Awadalla, P., A. Eyre-Walker and J. Maynard Smith, 1999. Linkage
disequilibrium and recombination in hominid mitochondrial DNA.
Science 286: 2524-2525.
Cann, R. L., M. Stoneking and A. C. Wilson, 1987. Mitochondrial DNA
and human evolution. Nature 325: 31-36. See also Wainscoat, Jim,
1987. Out of the garden of Eden. Nature 325: 13.
Kivisild, T. et al., 2000. Questioning evidence for recombination in
human mitochondrial DNA. Science 288: 1931,
www.sciencemag.org/cgi/content/full/288/5473/1931a
Underhill, P. A. et al., 2000. Y chromosome sequence variation and the
history of human populations. Nature Genetics 26(3): 358-361.
Yuehai Ke et al., 2001. African origin of modern humans in East Asia:
A tale of 12,000 Y chromosomes. Science 292: 1151-1153.
http://www.sciencemag.org/cgi/content/full/292/5519/1151
See also Gibbons, A., 2001. Modern men trace ancestry to African
migrants. Science 292: 1051-1052.
Further Reading:
Sykes, Bryan, 2001. The Seven Daughters of Eve. New York: Norton.
Dawkins, Richard, 1995. River out of Eden. New York: Basic Books.
