From: CurtAdams@aol.com
Date: Wed Apr 03 2002 - 11:30:09 MST
In a message dated 4/3/02 9:38:17, jacques@dtext.com writes:
>Cultural progress is likely to have a huge impact on both our
>environment and our nature in the next few decades.
Probably, but we can't stand still. The conservative position
is untenable. Only active processes can counter the effects of
evolution.
>Biological evolution in the sense of the natural selection of genes is
>negligible on that time scale. It's barely one or two generations !
Current selection pressure on increased fecundity is astronomical.
If say, the standard deviation of offspring number is 1 and the heritability
1/3, offspring # goes up 1/3 every generation and you have pressure
to speed up generation time.
>And if our nature failed to change significantly through evolution in
>the last 10 000 years since we dropped the hunter-gatherer way of
>life, leading to the disadaptation that was the object of my post, I
>fail to see how evolution will suddenly re-adapt ourselves to our
>exponentially changing environment in a few generation.
Going to agriculture is not the relevant shift, although I expect that has
changed human nature too, albeit less significantly. The shift is that
there's no limit on reproduction, which is quite recent. Freedom from
famine is only 300 years old even in England (Holland might be longer,
I don't have data; certainly nowhere else) and in most of the world it's
only
this generation. The demographic transition is more recent than that
and so alleles which permit the transition have been shielded from
detrimental selection.
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