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Tuesday 14 March 2017

Yet more iconoclasm. II

Nylon and Nylonase: Ann Gauger Disentangles an Evolutionary Icon - 
David Klinghoffer

Nylon is a human-synthesized substance. It’s familiar from ladies’ stockings and a variety of other uses, from toothbrush bristles to car parts.

It didn’t exist until 1935 years ago because it hadn’t been invented. Thus a strain of bacteria capable of digesting it would evidently need to do something novel that no bacteria had done before. When Japanese scientists in 1975 discovered such a bacterium at work, Darwinists later brandished this. They said it showed evolving new proteins is a breeze.

The nylon-degrading enzyme nylonase arose in the course of 40 years. That sounds like a score for evolution, right? Indeed, our theistic evolutionary friends over at BioLogos were in a triumphant mood on the subject a little while back on their Open Forum (“Biological Information and Intelligent Design: evolving new protein folds“).

Now they had Doug Axe on protein evolution, and by extension Stephen Meyer, beat! Writes biologist Dennis Venema:

Meyer’s argument (based on Axe) is that protein folds are too rare for evolution to find. The amino acids in the de-novo nylonase are a new sequence of amino acids — the frameshift mutation means that the old gene is being translated in a different reading frame, hence a new string of amino acids. This new, de novo, protein folds up into a functional nylonase.

If Meyer’s argument was correct, this could not happen. The probability of these new amino acids finding a functional sequence is, according to Meyer, only one in 10 to the 77th power. So, the fact that we can observe new functions coming into being shows that his estimate is grossly over-inflated.

In a brief window of time, some bacteria developed the ability to consume nylon. Ergo, no need for intelligent design in biology?

Not so fast, explains Discovery Institute biologist Ann Gauger. In an ID the Future conversation, she talked with Sarah Chaffee. Conclusion: “Nylonase was a pre-existing enzyme, had a pre-existing activity. It was easy to convert it to the ability to degrade nylon [by a] step-wise path. Therefore, there’s no reason to think that the enzyme is a newly derived enzyme from a frame shift. We don’t need that explanation.”

In short, as an icon of evolution, nylonase has no legs. Listen to the podcast here, or download it here.



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