Re: [asa] New fruit fly threat in Southern California

From: Bill Powers <>
Date: Thu Aug 06 2009 - 09:10:56 EDT


It seems to me that you are proposing a distinguishing mark for an
evolutionary event as opposed to one that is not.

The model I will refer to the Fat Man model.

Fat Man ( I think I have this history correct) as originally designed
had an engineering defect that was later corrected before it was dropped
on Nagasaki. The plans for Fat Man were stolen from Los Alamos and
delivered to the Russians. The Russians so carefully copied the designs
given them that they also produced the engineering defect, which they
also had to correct.

In the Fat Man model we have two species or objects, and we want to be
able to account for the relationship between the two. There are two
possibilities: they are correlated or they are independent. We can get
at this by assessing probabilities.

On Wed, 5 Aug 2009, David Campbell

>>> One of David's examples below provides another example of how evolutionary
>>> theorizing can *look* as if it contributes substantially to biological
>>> theory or practice while *in fact* being merely a redundant interpretive
>>> gloss.
> On the contrary, evolutionary models provide a reason for supposing
> that species that are presumed to be close relatives based on one set
> of data are likely to be similar in other features. (It would be
> possible to develop a non-evolutionary model with a similar
> prediction, though I can't immediately come up with one that isn't
> reducible to "the designer made things to look as though they
> evolved.")
> If the similarities were merely common constraints imposed by
> necessity on separately designed organisms, then there would be no
> reason to suppose that other features, not subject to the same
> constraints, would show the same resemblances. For example, a
> phylogenetic analysis of the flies based on cox1 genes (a
> mitochondrial protein) has no known reason to correspond to
> similarities in pheromones, except common ancestry. In fact, it would
> generally be advantageous for different species of similar flies that
> live near each other to have different pheromones to avoid confusion.
> --
> 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 Thu Aug 6 09:11:30 2009

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