>From me:
>> Cultural evolution has been occuring in earnest over only the last 10 to
>> 100 thousand years. This is an insignificant period, genetically. We are
>> all of one genetic mold, so to speak. In the time of recorded history
>> culture has been changing so rapidly that what makes a "fit" human brain is
>> dramitically different with each generation.
>
>I find "dramatically different" a strong claim. We're so dependent on
>communication [especially verbal] that the pressures there are plausibly
>fairly consistent.
I disagree. Eisenstein does an excellent job in "The Printing Press as an
Agent of Change" of showing how print no only changed the way people write
and publish, but how they speak and think as well. McLuhan, while
needlessly mystical, also brings up a number of telling examples in
"Understanding Media" of the way TV, radio, and other electronic media
effect our perceptions. Modern urban life is dramatically different than
even 50 years ago, much less 500 or 5000.
>Hmm. Let call a generation at 20 years [overestimate]. According to the
>above, cultural evolution has been running for at least 5000 generations.
>That is a VERY significant period, genetically!
>Assume that our population is large enough to avoid random genetic
>drift...[calculations follow]
I agree with the mathematics but disagree with the premise (isn't that
always the case?). You are assuming consistent pressure on a single
allele. Culture doesn't work that way. Dyslexia hasn't been selected
against becuase it wasn't a significant problem before printing.
Carpal-tunnel was unheard of a decade ago. The culture-environment is a
very rough and rapidly changing fitness landscape.
Reed
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Reed Konsler konsler@ascat.harvard.edu
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