> >From: zaimoni@ksu.edu
> >Date: Thu, 17 Oct 1996 00:57:20 -0500 (CDT)
> >Subject: Re: virus: Memes and Genes
>
> >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.
I agree that carpal-tunnel syndrome has not been selected against
significantly--the time-span is less than 1 full generation, and its
disabling/killing capability is relatively low. The first is more
important than the second.
=====
That's why I chose, as my focus, the alleles that affect the ability to
enunciate the key phonemes for recognizing speech--the ones most
distinguishable from background noise. Once the meme of verbal language
hits (proto)humanity, any alleles that interfere with those phonemes will be
STRONGLY selected against, CONSISTENTLY. This has a lot to do with the
rather sudden replacement (in geologic time) of the Neanderthal
pheno/genotype with the Cro-Magnon pheno/genotype. Some late
1970's/early 1980's attempts at reconstructing larynx structure [iffy, I
know] found that the Neanderthal attempt was better-adapted for eating,
but could not handle half of the vowels in any extant language. The
Cro-Magnon reconstruction was functionally indistinguishable from
current normal capabilities [physiologically]. I deliberately chose a
very weak selection coefficient; it is plausible that at a critical
mass, the selection coefficient would jump upwards considerably.
We are the *only* animal that can easily choke on what we eat or drink.
This is because our larynx structure is actively contra-adapted for
eating. Verbal communication [speech] must have enough of a selective
pressure to more the compensate for this, at some time in the past [and
definitely now!] *This* selective pressure DOESN'T change much.
I'll get back on the dyslexia comment after some research. If you're
correct, why are Caucasians and orientals underrepresented w.r.t.
dyslexia in America? By definition, conventional effort is not relevant.
However, dyslexia would effectively exclude one from the ruling
classes/high military rank anytime during the 1500+ years of the Chinese
empire: that empire had 16+ mutually unintelligible languages, and could
be controlled only because the written language was completely
independent of phonetics.