Re: [asa] Behe's Math... was Arrogance

From: David Campbell <pleuronaia@gmail.com>
Date: Tue Aug 21 2007 - 18:57:12 EDT

Several different combinations of mutations can enable chloroquinone
resistance, so Behe's assumption that a particular set of mutations is
needed is incorrect. It's also unknown how many times the same
mutations may have occurred, since the end result would look similar.
Secondly, evolving resistance to chloroquinone is not the only option
for malaria (a protist, incidentally, and so quite different from,
e.g., bacteria) to survive in the face of widespread chloroquinone
usage. For example, it could also survive by jumping to a less
protected host than humans. Yet another problem is that this is
painting a target around the arrow after you shoot, to use Dembski's
metaphor. The odds of no mutations occurring in a reproductive event
is essentially zero. Thus, organisms are going to change over time.
The probability of arriving at chloroquinone resistance is not high,
but the probability of getting somewhere is high. Another problem is
the fact that once a particular feature evolves, it's often less easy
for it to evolve again because the organisms starting to evolve the
feature compete against those that already have it. Conversely, those
that already have it don't need to evolve it again, so there's little
incentive to re-evolve features.

It's also worth nothing that numerous studies on mutation rates under
artificial selection regimes exist. The use of a single example out
of numerous options does not provide high credibility.

The latest PNAS has a paper suggesting that useful evolutionary
options are well-connected in sequence space, i.e., that there's
generally a way to evolve from point A to point B without going
through a significantly disadvantageous intermediate. I have only
abstract access, so I can't assess details:

S. Ciliberti, O. C. Martin, and A. Wagner
Innovation and robustness in complex regulatory gene networks
PNAS 2007 104: 13591-13596;

-- 
Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"
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Received on Tue Aug 21 18:57:40 2007

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