Saturday, December 13, 2014

This Paper Explains How Potassium Channels Evolved

Promoting Evolution Literacy

The evolution of proteins such as potassium channels, according to a recent paper, occurs easily and is a good opportunity for communicating evolutionary principles, promoting evolution literacy, and refuting the misleading message of “design creationism” which is empirically unfounded and conceptually wrong. Nothing more than mutations and natural selection are sufficient to explain the origin of highly specialized proteins such as potassium channels. Those are important claims given the consistent message from both experiments and theory that protein evolution is so astronomically unlikely it can safely be put in the “impossible” category. There is only one problem: the paper is all wrong.

One problem with evolutionists writing papers which are peer reviewed by other evolutionists, for consumption by yet other evolutionists, is the lack of scientific scrutiny. In this case the paper presents a silly calculation for the evolution of a potassium channel protein that wouldn’t stand up even to minimal legitimate peer review. The calculation multiplies a nominal mutation rate per generation by a nominal generation rate per year by several millions of years to obtain 483, which is the length of the protein coding gene sequence.

In other words, all that is needed are millions of years and roughly a mutation per nucleotide and, there you have it, a potassium channel gene emerges. Along the way the paper sports the usual teleological language (natural selection is a “tinkerer”), evolution is full of serendipity (the cellular chemical apparatus that magically generates new proteins is itself a product “of Darwinian evolution”) and so forth. The paper, as they say, isn’t even wrong. But at least it promotes evolution literacy.

6 comments:

  1. So that's 483 consecutive beneficial mutations?

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  2. Yes, that's about it. There needs to be a gradual path of ever increasing fitness, all the way to the final protein.

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  3. How long would it take for a lab to simulate these 483 consecutive beneficial mutations -- replay evolution, so to speak. Such an experiment would be, in my opinion, the logical next step, rather than declaring success and taking the bow. Bet bones that if they tried they wouldn't be able to get from there to here.

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  4. I did a heavy skim of the paper you are talking about. 'Best I can tell he is very nearly approximating the "wiesel" algorithm -- assuming that any "correct" mutation at any point will be selected by natural selection. If the wiesel algorithm was a realistic view of how biology really works, I think I would abandon my ID leanings.

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  5. "If the wiesel algorithm was a realistic view of how biology really works, I think I would abandon my ID leanings."

    Except that creating a protein, as improbable as that is, is really the easy part. Coming up with a use for the protein and the instructions to make it participate in that use, now that's another story. How does the wiesel algorithm weasel out of that one? ;-)

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  6. I am an organic chemist, and I lack some insight in DNA mechanisms of mutation. But, if the argument of the article is correct, there are few mutations possible for each codon.
    For example, AAA can only generate AAG, AGA, GAA, after AGG, GAG (fun!), GGA and GGG, and four aminoacids are encoded, and GGG can take only the reverse way. Other cases should be more critical.
    This is a punch not for ID, but for the darwinism.

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