Reflectorites
On Mon, 09 Oct 2000 08:25:28 -0500, Susan Brassfield Cogan wrote:
[...]
>SJ>Susan said "we can watch ... natural selection happen every day ..." Wesley
>>said "Natural selection, though, is notoriously difficult to empirically
>>isolate as a mechanism of action."
>>
>>How can Susan "watch" something "happen every day" that is "notoriously
>>difficult to empirically isolate"? IOW how does Susan know she is watching
>>"Natural selection"?
SB>Wesley was talking about isolating natural selection from drift and my
>understanding was that he was talking about populations over a large amount
>of time.
Agreed. And I am talking about how Susan isolates "natural selection from
drift" and how Susan can "watch ... natural selection happen every day ..."
in only individuals in her home (see below).
Why does Susan think that Wesley *needs* to see "natural selection" in
"populations over a large amount of time"?
SB>You see natural selection every time you spray for roaches or
>don't take all your antibiotics.
I would have no problem with this if it *was* natural `selection', i.e.
differential survival and reproduction.
But as a matter of interest how does Susan *see* "natural selection
*every* time you": 1. "spray for roaches" or 2. "don't take all your
antibiotics"?
In the case of 1. if a "roach" survives after Susan sprayed it with
insecticide, how does Susan "see" that it did not survive because she
did not spray it properly? Also how does Susan "see" that the "roach"
does not die later without offspring?
As for 2. how does Susan "see" bacteria, let alone that they have been
naturally `selected' against the effects of the "antibiotics"?
Finally, if Susan did manage to "see" the above, how does she know
that what she sees is not natural `selection' but instead genetic "drift"?
[...]
Steve
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"Biologists must constantly keep in mind that what they see was not
designed, but rather evolved." (Crick F.H.C., "What Mad Pursuit: A
Personal View of Scientific Discovery," [1988], Penguin: London, 1990,
reprint, p.138)
Stephen E. Jones | Ph. +61 8 9448 7439 | http://www.iinet.net.au/~sejones
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