# Adam and Eve and Jerry and Bryan and Vincent

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.

This entry was posted in Evolution, Intelligent Design by Joe Felsenstein. Bookmark the permalink.

Been messing about with phylogenies, coalescents, theoretical population genetics, and stomping bad mathematical arguments by creationists for some years.

## 103 Replies to “Adam and Eve and Jerry and Bryan and Vincent”

1. Patrick
Ignored
says:

SophistiCat: Unfortunately, poor coding and documentation practices were quite typical when I was in academia, so I would sooner blame incompetence than malice.

Fair enough, particularly with respect to the coding. This kind of program shouldn’t be held to the standards of enterprise software.

However, I would expect to see a detailed description of the model being implemented. That isn’t available for Mendel’s Accountant. This is in stark contrast to examples like Schneider’s ev which is documented very clearly and extensively.

2. vjtorley
Ignored
says:

Hi Professor Felsenstein,

Thank you very much for your reply. Just to be clear, I was envisaging an original ancestral population of just one couple, one million years ago. I take your point that the data certainly don’t point to the truth of the Multi-Germic Hypothesis. However, it seems that you don’t think the MGH I proposed is positively ruled out by the available evidence.

Re Noah’s flood: I don’t envisage it as killing off the entire human race. There has been a (highly speculative)suggestion that Noah’s flood may have been a tsunami triggered the the collision of a comet with Earth about 5,000 years ago: http://discovermagazine.com/2007/nov/did-a-comet-cause-the-great-flood . But even that would have killed off no more than 80% of humanity.

Thanks once again.

3. Joe Felsenstein
Ignored
says:

Re Noah’s flood: I don’t envisage it as killing off the entire human race. There has been a (highly speculative)suggestion that Noah’s flood may have been a tsunami triggered the the collision of a comet with Earth about 5,000 years ago: http://discovermagazine.com/2007/nov/did-a-comet-cause-the-great-flood . But even that would have killed off no more than 80% of humanity.

I suppose I should stay out of discussions about theology, but I would just comment that you’ve now started down the slippery slope towards “The Noah / Ziusudra / Utnapishtim / Gilgamesh story was inspired by a big local flood from which a farmer and his family escaped with his animals on a raft.” Maybe in Mesopotamia, maybe in the basin of the Black Sea. Which might well be, and doesn’t create any prediction about human genomes.

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