Travel Reference
In-Depth Information
The mitochondrial “Eve”
Mitochondrial DNA studies show that the San form an important part of
our family tree. The role that the San have played in our history became clear
during the search for the mitochondrial Eve.
Just as it is possible to trace some Mongolian Y chromosomes back to
a single ancestor who lived a thousand years ago, it is possible to trace the
ancestry of all present-day human mitochondrial chromosomes back to
one woman who lived in the distant past. Descendants of her mitochondrial
chromosomes are carried by every human alive today. All the mitochon-
drial chromosomes that were carried by other women who lived at that time
have been lost over the intervening millennia. All the dif erences among our
present-day mitochondrial chromosomes have accumulated as a result of
mutations since the time that ancestral woman lived; none date to before
her time.
It is unfortunate that the woman in question has become known as the
mitochondrial Eve. The world's press, and even some careless scientists and
science writers, have repeatedly claimed that she was the ancestor of all pres-
ent-day humans. This is not true, as other scientists have gone to great pains
to point out with increasing levels of irritation. There were other women
living at the time of the mitochondrial Eve, probably many of them in many
dif erent tribes, but by chance all the descendants of their mitochondrial
chromosomes have become lost during the thousands of human genera-
tions from that time to this. At some point these other mitochondrial chro-
mosomes all ended up in males or in females who had no children.
Even though the mitochondrial chromosomes of those other women
have been lost by chance, some of the genetic information carried by their
other chromosomes has survived. The women and the men of their tribes
contributed some of their nuclear genes to people living today. Because of
these contributions, our genetic legacy is far larger—and far more inclu-
sive—than the little bit of mitochondrial DNA that was carried by the mito-
chondrial Eve.
