Expelled and the Challenge to Population Genetics

What? You thought I was serious? I'm Mad, not crazy. But the release of Expelled gives me an opportunity to note one facet of creationist stupidity.

A while ago, in response to Michael Egnor, who features prominently in the movie Expelled, I discussed how creationists party like it's 1859. As the movie Expelled inadvertently demonstrates, they fail to recognize that we biologists have done a little work since Darwin's Origin of Species. Specifically, creationists never discuss either population genetics or phylogenetics because, if they did, they would get their asses handed to them (and I think a fair number of them are too stupid to master material many college undergraduates are capable of learning).

Anyway, regarding Expelled, I found this very interesting bit about the neutral theory which is also something creationists never discuss:

In 1967, Motoo Kimura published a paper showing that the genetic content of the genome must have been influenced substantially by selectively neutral genetic drift. Other authors built on this work to argue that molecular evolution might be dominated by neutral drift, and not by natural selection. As William Provine writes, "The initial reaction to the neutral theory of Kimura, King and Jukes was generally very negative" ("The Neutral Theory of Molecular Evolution, Random Drift and Natural Selection." In Cain A.J. and Provine W.B. "Genes and ecology in history." Reprinted in Berry R.J. et al (eds) 1991. Genes in ecology: the 33rd Symposium of the British Ecological Society. Blackwell, Oxford, p. 23-25). Provine adds, "when DNA sequence data began to pour in after the early 1980s, the situation changed dramatically." The abundance of selectively neutral differences within populations and among species matched the predictions of the neutral theory, and could not be explained by selection alone.

"By 1990," Provine continues, "molecular evolutionists had largely abandoned the null hypothesis of selection to explain observed molecular differences and accepted the neutral theory.... Even the molecular evolutionists who argue for the importance of selection at the DNA level construct and use models for which the neutral theory is the assumption." This represented a radical change in the scientific approach to evolution, which had formerly considered natural selection to be paramount. Clearly, evolution at the molecular level operated by different rules. Although the neutralist hypothesis was a break with traditional neodarwinism, its incorporation into evolutionary biology was smooth -- once researchers had the ability to gather DNA sequence data and test the predictions of the theory.

So the scientific consensus can be and is challenged regularly. There is no unchallengeable orthodoxy, which is what Expelled would have you believe. The preceding stories are just a few well-known examples of biologists who challenged the scientific consensus, including principles of Mendelian genetics and of Darwinian evolution. These scientists prevailed because they did good science: they backed their challenges with successful predictions and empirical evidence. And, they were right. Scientists are constantly questioning, refining, and expanding theories, including evolution - and natural selection theory. As Michael Shermer writes, "Anyone who thinks that scientists do not question Darwinism has never been to an evolutionary conference."

Here's another thing that isn't discussed in Expelled. Neutral theory--a result of which is that most adaptive variation is rapidly lost--is the theologically challenging part, not natural selection. ID creationism: lousy science, even crappier theology.