[Taxacom] Re Teleology example

[Michael Heads]

David, you agree that 'Not everything in biology exists because it helps an
organism'. We're saying that *nothing* exists because it helps the
organism. We don't have eyes because they're helpful - vision is the end
result and the end doesn't explain the process except in teleology. Why is
the mammalian heart a helix? Is it really because it's helpful? Or is it
simply a byproduct of long term trends?

Michael Heads
On Thu, Mar 7, 2013 at 7:46 PM, David Winter <david.winter at gmail.com> wrote:

> John Grehan has said:
>
> At various times I have raised, in this and other lists, the continued
> presence of intelligent design theology in science in the form of
> explicit teleology. Often the response is "that is not what they
> really intended".
> Here's a nice explicit example: "it's hard to see how these hair-like
> processes would evolve if they didn't serve a purpose." This from
> David Winter, "a PhD student in evolutionary genetics who very
> occasionally thinks he has something that the internet simply needs to
> know..." See http://sciblogs.co.nz/the-atavism/tag/new-zealand/
>
>
> John, that is not what I really intended.
>
>
> In fact, it's fairly obvious from context there is no teleology in the
> argument I was making (for a popular audience, in an informal
> publication)
>
> "I try very hard to avoid the sloppy thinking that presumes there is
> an adaptive explanation for every biological observaton, but it’s hard
> to see how these hair-like processes would evolve if they didn’t serve
> a purpose. The larger hairs are presumably made from the same calcium
> carbonate minerals as the rest of shell, and calcium is a precious
> resource for snails (so much so that empty shells collected from the
> field often show signs of having been partially eaten by living
> snails). In those species with finer projections, the hairs are an
> extension of the “periostracum”, a protein layer that covers snail
> shells.  If we presume that snail hairs come at a cost, in either
> protein or calcium, what reward are they hairy snails reaping from
> their investment?"
>
>
> That is
>
> * Not everything in biology exists because it helps an organism
> * That being said, the hair-like processes many snails sport cost
> something (in terms of resources and energy)
> * It is unlikely that a costly feature will be maintained if it
> doesn't benefit the organisms carrying it (as mutants that don't have
> the trait could out-compete those paying the cost)
> * Given all of the above, it's reasonable to presume the hairs are
> helping their carriers to survive and reproduce, so let's find and
> tests hypotheses as to how that might happen.
>
> Short of an alarm bell which might go off upon seeing the word
> "purpose" in the widely-used phrase "serve a purpose" I can't see what
> you object to.
>
> I obviously need to update my biography, indidently, as I'm now a PhD
> graduate who quite frequently has things the internet needs to know.
>
> (BTW, I don't subscribe to taxacom - if anyone wishes to include me in
> replies to this email you'll need to reply-all)
>
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