Bryan College in Dayton, Tennessee has recently added to its statement of faith, to which faculty members must subscribe, a “clarification” that
We believe that all humanity is descended from Adam and Eve. They are historical persons created by God in a special formative act, and not from previously existing life forms.
Jerry Coyne at his Why Evolution Is True blog has pointed at this with alarm here, and he linked back to the Chattanooga Times Free Press story here. Jerry cites studies showing from the amount of variability in human populations, that effective population size of the individuals leaving Africa in the Out-Of-Africa event cannot have been much less than 2250, and the effective population size in Africa cannot have been much less than 10,000.
VJTorley at Uncommon Descent has published a firm response, saying Jerry was “In a pickle about Adam and Eve” and saying that when he said that “2250 is greater than two”
Evidently math is not Professor Coyne’s forte.
Note: 2,500 isn’t the same as 2,250.
Note: 2,250 + 10,000 = 12,250.
The math lesson is over.
He also quotes a paper by Luke Harmon and Stanton Braude, which notes that effective population sizes can be larger than actual population sizes, and says
It’s rather embarrassing when a biology professor makes mistakes in his own field, isn’t it?
Has Jerry gotten himself into a pickle? I have some background in this area — I have worked on coalescent trees of ancestry of genes within a species, I wrote one of the two basic papers on effective population size of populations with overlapping generations, and I even shared a grant with Luke Harmon two years ago.
A few simple points:
1. 10,000 + 2,250 = 12,250 all right, but in fact that number is even greater than 2.
2. Effective population size can be greater than population size. It can get as much as 2 times higher. That still leaves us with a long way to go.
3. The Bryan College administration does not know how to write a Clarification. Their statement says that all humanity are descended from Adam and Eve, but does not make it clear whether there could have been other ancestors too. I suspect they meant that there weren’t any.
4. According to UD’s own statements, Intelligent Design arguments are supposedly not statements about religion, so that ID arguments do not predict anything about Adam and Eve. ID proponents are being slandered when they are called creationists, we are told repeatedly. So why the concern about Adam and Eve at UD?
So was Jerry wrong? About Adam and Eve, no. Though he is wrong when he says that his “website” is not a blog.