RE: Flagellum Re: Definitions of ID

From: Nelson Alonso (nalonso@megatribe.com)
Date: Tue Sep 12 2000 - 11:14:02 EDT

  • Next message: Nelson Alonso: "RE: Blood clotting and IC'ness?"

    Fam:
    Given the suggestion that the flagellum is IC and therefor shows evidence of
    intelligent design and therefor intelligence I would like to offer the
    follow
    data points against this idea.

    Ian Musgrave shows his views on evolution of the flagellum

    http://x59.deja.com/[ST_rn=ps]/getdoc.xp?AN=598548093

    archived at

    http://www-personal.monash.edu.au/~ianm/flagella.htm

    Nelson:
    I would like to address these links. Ian here thinks that the flagellum,
    because it has some parts similar to the secretory apparatus, evolved from
    the type III secretory system.Thus all the parts could be removed and
    selection will still be able to select for the flagellum since it is acting
    as a secretion system. I like Tim's analogy when Ken Miller brought this
    objection up:

    "We will not be impressed by the clever fellow who points
    out that it could run down the street in the absence of wheels if you
    put it on the back of an elephant, and argues that bikes with wheels
    evolved spontaneously from bikes on the backs of elephants. "

    But there is a more fundamental problem. The type III secretory system is
    actually quite complex. And it contains quite a few other parts that it
    needs for it's function. It also sits causally downstream from the
    flagellum, which would indicate that it may have evolved from the flagellum
    and not vice versa. In this review of a paper:

    Type III Secretion Machines: Bacterial Devices for Protein Delivery into
    Host Cells
     Jorge E. Galan and Alan Collmer
     Science 1999 May 21; 284: 1322-1328.

    "Made up of more than 20 proteins, type III secretion systems are the most
    complex of all known protein secretion systems in bacteria. The observation
    that these virulence-associated systems were always linked to phenotypes
    related to interactions between bacterial pathogens and their animal or
    plant hosts intrigued researchers in this field from the outset."

    It goes on to say that they require many chaperones for many of it's
    proteins.

    "Despite the architectural similarity between flagella and type III systems,
    the structural components of the needle complex share limited sequence
    similarity with components of the flagellar basal body "

    Thus the reductionist viewpoint's prediction is falsified. And to view the
    flagellum as a type III system has no basis except as an apologetic.



    This archive was generated by hypermail 2b29 : Tue Sep 12 2000 - 11:10:59 EDT