Re: Mitochondrial Eve

Gordon Simons (gsimons@email.unc.edu)
Sat, 15 May 1999 10:57:45 -0400 (EDT)

Many thanks are due Glenn for his recent report and commentary on
"Mitochodrial Eve." The discovery that paternal mtDNA is an important
component to our understanding of human evolution is extremely important.
And it seems that the discovery supports -- i.e., is consistent with and
thus provides some confirmatory evidence for -- several of his theses.

I would like to make two points, one concerning his last comment, and one
about statistical studies based on constant mutation rates.

1. Glenn concludes:

> This data, along with the possible Neanderthal/Human hybrid reported
> earlier, screams out for a new apologetical treatment. Christians who
> have argued for a humanity that was less than 100,000 years old and
> genetically separate from archaic Homo sapiens such as Neanderthal and
> Homo erectus are in danger of following the path traveled by the
> young-earth creationists. That is, they are beginning to ignore
> important pieces of data in order to support their preferred theological
> interpretation. This is a too often occurrence among many christian
> apologists.

Whose house is out of order? Human biologists or Christians? These papers,
if they "scream" for anything, scream for a reassessment by human
evolutionists of many of their present cherished views. The apple cart
has been turned upside down, and much scrambling has occurred. This is not
to say that the basic picture of human evolution has been altered. But
much recent work based on mutational studies now seems suspect.

It is nice that there are a few Christian folks like Glenn who are
attempting to match Christian apologetics with new data, but most
Christians have more important things to do than, schizophrenicly, to
match Christian apologetics to the ebbs and flows of scientific research
-- particularly during times of significant transition.

2. This gets to my second point. Glenn quotes Hagelberg et al (1999):

> " .... For example, position 16129 is considered to be one of the most
> hypervariable in human mtDNA, with a rate approximately eight times
> higher than the background mutation rate in the first hypervariable
> segment of the human mtDNA control region ...

Many statistical studies based on mutation rates have *assumed* a constant
mutation rate. A ratio of eight to one is not even close to constant. This
suggests (to me at least) that any study which must depend on an assumed
uniform mutation rate needs to viewed with considerable skepticism.

Gordon Simons