5 October 2006 (ScienceNOW) – For some biologists, “punctuated equilibrium” is a radical idea. The term was coined in the 1970s to describe an uneven pace of evolution in the fossil record. But because it posits that evolution happens in bursts, punctuated equilibrium goes against the notion that evolution inches forward in tiny steps guided by natural selection. Now evolutionary biologists have shown that evolution in the genome also has fast and slow speeds, and that natural selection isn’t always governing genetic change…

Pagel attributes the bursts of genetic change not just to natural selection, but also to an additional phenomenon called genetic drift, in which some genetic changes become incorporated into the genome even if they are not beneficial. Drift is likely to happen in the small populations that typically characterize an incipient species. As a new species settles into its new niche and its population grows, drift becomes less common, and the rate of genetic change slows. As a result, “We think species change very rapidly at first, and then they slow down,” says Pagel.

The work is causing a stir. “This study supports the idea that punctuated equilibria exist but also suggests a limit to its overall effect on genetic change,” comments Don Waller, an evolutionary biologist at the University of Wisconsin, Madison. But, despite the precautions Pagel took, Brian Charlesworth from the University of Edinburgh, U.K., worries that multiple changes at the same base in species that have been around a long time might have skewed the results.

I’ve always wondered how puctuated equilibrium is supposed to explain anything at all. If natural selection is supposed to be the primary driving force of evolution, and if it is as perfect a selector as evolutionists like to make it out to be, how is it that punctuated equilibrium finds a way to drift around it when the theory requires it. Yes, if you take a small population away from a larger population and stick it somewhere else it may survive in this new environment with a less-fit genome, but how often does this occur, and how is a step back to truly be considered as a step forward (other than that it promotes diversity).

One thing that should be noted here is that the study didn’t actually back up anything at all. It merely took the position that “genetic drift” occurs and can be advantageous without any substantiation, and then took the fact that there are discontinuities in the genetic data to push this idea as a requirement (since there must be a natural explanation for every design, or at least, there must be for it to be science, right?) All the problems of selection vs. entropy, irreducible complexity, and fitness (landscape) peaks are quietly brushed under the rug as naturalistic dogma rules the day.

But I’m sure it has pretty graphs, at least…

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