Humans are both very like and very different from other species we find on Earth. At the sub-cellular and biochemical level, the similarities, the almost universality of the DNA code and its property of self-duplication and storage of genetic information is breathtaking. On the other hand, no other species has succeeded in the scope and breadth of it’s colonization of this planet. Much of the “success” in growing a population that now exceeds seven billion individuals can be attributed to our being a social species. Sociability and its evolutionary roots have been well studied. However there does seem to be something missing. The rapid runaway expansion of human culture and the extraordinary flowering of human art, which might be attributed in turn to the literal expansion of the human brain seem to require further explanation. Continue reading
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.
Seriously, are the ID proponents at UD ever going to wonder why Gould and Eldredge remained persuaded that common descent occurred, and that “punctuated equibrium”, although contrary the uniformly incremental pattern that Darwin envisaged, was nonetheless consistent with Darwin’s proposed adaptive mechanism of heritable variation in reproductive success?
Because Darwin was indeed wrong about uniform change. Unlike us, he didn’t have computers with which to model the predicted output of his mechanism. Indeed he didn’t even know what the vector of heritability was. We do. Here’s a sample output from Eureqa, a program that uses Darwin’s proposed mechanism to “evolve” equations to fit data:
If there is nothing beyond the material universe, judgments of right and wrong are no more informative than pan-hoots.
says “news” at Uncommon Descent. Well, I have no idea what a pan-hoot is, but presumably it is a not-informative thing.
There’s a lot of discussion of censorship swirling around the ID/evolution/online world right now, which I find very odd. Apparently the magazine Nautilus has closed a comment thread (without apparently deleting any comments) on the basis that “This is a science magazine, and our comments section isn’t the place to debate whether evolution is true”.
Accusations of “censorship” by “evolutionists” have been flying around for a while now, at least since the Expelled movie and it resurfaced regarding the withdrawal of the Biological Information: New Perspectives book from the Springer catalogue. And now, recently, Jerry Coyne has been named “Censor of the Year” by the Discovery Institute.
My own instincts tend against censorship, and although I do not think that all censorship is bad, I would certainly rather err on the side of too little than too much. Here, as I hope everyone knows, only a very narrow class of material is ever deleted, and only a very narrow class of offenses bring down a ban.
But what is censorship, and who, if anyone, is censoring whom in the ID/evolution debate?
Let’s lay this one to rest, shall we?
All science is observational – observations are what we call “data”.
All science is predictive, whether it concerns events that happened in the past, and are unlikely to occur again, or events that are reproducible.
Allan Miller’s post Randomness and evolution deals with neutral drift in the Moran model applied to a bag of M&Ms. Much of the discussion has focused on the question of counting generations in a situation where they overlap. I think it’s a good idea to divert that part of the discussion into its own thread.
Here are the rules. Start with a population of N M&Ms. A randomly chosen M&M dies. Another randomly chosen M&M gives birth to a child M&M. Repeat.
Because the focus of this thread is generation count and not fixation, we will pay no attention to the colors of M&Ms.
How do we count generations of M&Ms?
Lizzie Allan Miller said:
Here’s a simple experiment one can actually try. Take a bag of M&M’s, and without peeking reach in and grab one. Eat it. Then grab another and return it to the bag with another one, from a separate bag, of the same colour. Give it a shake. I guarantee (and if you tell me how big your bag is I’ll have a bet on how long it’ll take) that your bag will end up containing only one colour. Every time. I can’t tell you which colour it will be, but fixation will happen.
I’ve written an interactive browser based version you can explore this idea with.
What is it with ID proponents and gambling? Or rather, what is it that makes people who play p0ker and roulette think that that gives them a relevant background for statistical hypothesis testing and an understanding of stochastic processes such as evolution? Today, “niwrad”, has a post at UD, with one of the most extraordinary garblings of evolutionary theory I think I have yet seen. He has decided that p0ker is an appropriate model this time (makes a change from coin tossing, I guess).