Saturday, December 29, 2007

Evolution in action

For decades, industrial melanism was held up as the textbook example of evolution in action. Practically every biology textbook (except possibly those published in Kansas) had the example of the peppered moth, whose dark form had become dominant in response to increased levels of industrial pollution (well, technically due to the light ones being more likely to be eaten as they were more easily seen when sitting on soot-darkened tree-trunks). But a few years ago, someone suggested that the original experiments on differential predation were flawed. Naturally, the Creationists lept at it - evolution had been disproven! But I doubt they'll be so vocal about the latest news on the issue. Cambridge professor Michael Majerus has redone the experiments, and the results support the original hypothesis:

"I conclude that differential bird predation here is a major factor responsible for the decline of carbonaria frequency in Cambridge between 2001 and 2007," Professor Majerus said.

"If the rise and fall of the peppered moth is one of the most visually impacting and easily understood examples of Darwinian evolution in action, it should be taught. It provides after all the proof of evolution," he said.

And that proof is now that much stronger and more survivable for the additional testing. Unfortunately, I doubt the Creationists will recognise that either.

(Hat tip: Crooked Timber)