Re: Natural Selection (was: Breast Size)

Bryant (mycol1@unm.edu)
15 Jun 1995 08:27:39 -0600

In article <3rniu4$knf@tardis.trl.OZ.AU>,
Jacques Guy <jbm@newsserver.trl.oz.au> thinks he sees a contradiction:
>mycol1@unm.edu (Bryant) writes:
>
>>Phil, I hate to argue semantics like this. But, I didn't say that
>>natural selection is driven "to" anything. I said that adaptations can
>>safely be referred to as functional--"opposable thumbs are for grasping."
>>That's all I've meant to convey in this thread.
>
>However: [Bryant _also_ said:]
>You don't evolve. Lineages and populations evolve. Because fitness
>advantages shape many traits (adaptations), it's fair to say that those
> ^^^^^
>traits evolved TO provide those fitness advantages. Our opposable thumbs
>^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^
>evolved TO grasp
>^^^^^^^^^^

>The ^^^^^^ are my emphasis. The capitalization of "TO" is Bryant's
>emphasis.

Indeed. Note that in the original (second quoted) passage, I said that
adaptations can safely be said to be adapted TO do things (a simple,
functionalist argument).

In the second (first quoted) passage, I was (ineffectively) explaining
that I *didn't* mean by this (first) line of argument that natural selection
is "driven" or goal-oriented in a forward-looking manner. Neither, however,
is it completely "random," as has been asserted.

You have (collectively) --or perhaps *I* have-- made the point about
sloppy language being misleading, however. Specifically, I shouldn't
have said that "I didn't say...TO..." when indeed I had! I should've
said, "when I said...TO...I didn't mean...goal directed, etc."

I do think that short-hand is inevitable and useful within a field,
however, so long as everybody knows what the short-hand is really
saying. I.e., "thumbs evolved to grasp" or "infanticide is an adaptive
cessation of investment" are shorthand for "opposable thumbs, arising
through a series of selectively favored mutations, offered their owners
selective advantages sufficient for the retention of the genes for that
trait," and "psychological evaluative mechanisms seem to have evolved in
the human brain which process cues of unhealth in an offspring in a
manner resulting in hostility or apathy towards the infant, albeit
subconscious..."

Fair enough? Thanks.

Bryant