Darwinism News

Jerry Coyne vs. Allan Miller (TSZ) vs. Behe

Spread the love

natural selection cannot build any feature in which intermediate steps do not confer a net benefit on the organism.

Jerry Coyne
as reported in Hopless Matzke

contrast this with what Allan Miller said at The Skeptical Zone

It is sufficient that NS does not act too strongly against, not that it must act for, a particular change.

Allan Miller
TSZ Allan Miller says natural selection has to fail for evolution to work

I actually agree with Miller to the extent that Miller agrees with Michael Lynch and Mae Wan Ho

many genomic features could not have emerged without a near-complete disengagement of the power of natural selection

Michael Lynch
opening, The Origins of Genome Architecture

and

a relative lack of natural selection may be the prerequisite for major evolutionary advance

Mae Wan Ho
Beyond Neo-Darwinism

What does this all mean? The fact that a complex feature may be selectively advantaged does not imply that natural selection was the mechanism that evolved the feature. It may well be that the intermediate transitional forms were selectively disfavored, hence “luck despite the odds” enabled the feature to finally emerge. But in such case, this is an appeal to pure luck not Darwinian mechanisms!

Once such a feature emerges, it could be selectively favored, but this does not mean at all that the steps leading to the final product were selectively beneficial. I highlighted a fallacy that is common in evolutionary biology: Selection is falsely called a mechanism when instead it should be labeled an outcome.

I found Coyne’s quote in Hopless Matzke, and because I still hear some swearing by the power of Darwinian selection, I felt I occasionally have to contest such devoted belief to an insufficient cause for complex designs in biology.

Allan Miller wins the battle with Coyne, but loses the war with Behe’s irreducible complexity since Allan’s claim is essentially an appeal to blind luck despite the odds.

HT David Berlinski and Tyler Hampton

5 Replies to “Jerry Coyne vs. Allan Miller (TSZ) vs. Behe

  1. 1
    Joe says:

    Natural selection is eliminative- whatever is good enough to survive gets the chance to reproduce.

    Ernst Mayr in “What Evolution Is” page 281:
    On natural selection being a pressure or force

    What is meant, of course, is simply that a consistent lack of success of certain phenotypes and their elimination from the population result in the observed changes in a population

    On the role of chance:

    The first step in selection, the production of genetic variation, is almost exclusively a chance phenomenon except that the nature of the changes at a given locus is strongly constrained. Chance plays an important role even at the second step, the process of elimination of the less fit individuals. Chance may be particularly important in the haphazard survival during periods of mass extinction.

  2. 2
    Johnnyfarmer says:

    Well let me pose an interesting thought … would flagellated bacteria survive if you remove their flagellum ?

    If they can survive without flagellum then why would flagellum be selected for ????

  3. 3
    Johnnyfarmer says:

    Do single cell organisms need mobility to survive. Obviously they do not. Many simply remain stationary absorbing dissolved nutrients within close vicinity of their cell walls. As nutrients are depleted more move in by diffusion.

    If nutrients are always being replenished by diffusion what would be the big advantage for bacterial cells to evolve mobility? Why would mobility be selected for?

    If immobile strains of bacteria thrive and coexist in the same environment with mobile strains then really what is the advantage to being mobile?

    And if the flagellum did not evolve then it must have been designed. Was it designed for a specific purpose … such as to improve digestion in a host ? If mobile strains would grow faster than immobile they would divide sooner which would mean they could multiply faster within a host’s digestive system… which would be beneficial to the host

    Was the flagellum designed to aid digestion in a host’s intestinal tract or did the flagellum evolve because of selection? (assuming we could somehow get around the problem of irreducible complexity)

    Intuitively I just can’t comprehend why slight incremental increases in mobility would be selected for!!!

  4. 4
    Johnnyfarmer says:

    In a scenario where flagellum evolves through many transitional forms why would these transitional forms become extinct?

    ….Because the fittest one is the one that swims a little faster ?????

    And I also wonder why evolution would select for a fast rotating (10,000 rpm) strain when that strain typically functions at a much slower rpm.

    Selection must have been in the form of a fast moving predator such that the slower swimming bacteria become prey…. (which seems a bit far fetched)

  5. 5
    scordova says:

    Intuitively I just can’t comprehend why slight incremental increases in mobility would be selected for!!!

    Exactly, the intermediate stages could actually be liability, not a benefit.

Leave a Reply