In a message dated 5/1/01 6:43:13 AM, rhanson@gmu.edu writes:
>>In Volume 98, Numbers 3-4 of the the International Journal of Neuroscience,
>>Dr. Miles Storfer, The Foundation for Brain Research, Delray Beach, FL. USA,
>>proposes that the prenatal development of human intelligence can be
>>influenced by our parents' postnatal environment - not by altering the DNA
>>sequences of our protein-coding genes, but by changing the "developmental
>>blueprint for gene expression" that unfolds in the womb (to wit, changes in
>>the timing and extent of gene expression in environmentally-stressed
>>portions of the developing neocortex). ...
>
>Is this guy a flake or a genius? I just talked to William Dickens, who
>wasn't impressed, but I was wondering: would our local experts in biology
>and/or neurology might pass judgement? He seemed to me to have an impressive
>command of a wide range of relevant evidence, but them I'm no expert the
>topics he discusses.
The writer is very bright but, at least on this topic, writes as if he's
nuts. The idea that parents manipulate is plausible and does happen; but
it's not common and I would expect strong data to support it over more
straightforward explanations of parental effects like well-fed mothers can
make better babies. His detailed modeling shows a lack of knowledge about
how imprinting and parental effects work and has a lot of grasping at straws.
Reading it feels very surreal as he's obviously done his homework on the
terminology and literature and then misses some real basics, or makes very
biased presentations.
Mothers do manipulate progeny pre-natally. An ape example is gorillas;
female gorillas produce male-skewed offspring when in good condition and
female-skewed offspring when in bad condition. However, for the mother to
manipulate offspring intelligence would require that the mother ascertain the
values and cost of intelligence to her children, that there be some
substantial trade-off, and that the trait is simple enough to be manipulated.
All this is very iffy.
The claims for environmental irrelevance in IQ are breathtaking. He cites
the Dutch Hungry Winter of 1944 (a mild famine lasting a few months) as
"only" reducing IQ 1.9 points. Gosh, a hungry childhood would "only" reduce
IQ about 90 points, at that rate. No mention of other work on calorie
restriction in very young
monkeys showing profound mental retardation.
The myopia/imprinting correlation just consists of citing unexplained
variance in poorly controlled or downright anecdotal studies. E.g. the
indian studies where myope children of non-myope parents have 8+ hours of
close work per day. 8 hours! That's a child labor subgroup; there will be
some major environmental differences with the myopic parent group, both with
children and with parents. He "proves" neuronal complexity causes mental
capacity with 3 case studies (and then later says it's cortical size that
matters!). He has this implicit assumption that if children differ when
starting school, it must be due to genetics. ??
The claim that fathers must make a stronger genetic contribution because
mothers provide more of the environment really doesn't hold any water. A
correlation between mother and child intelligence due to that would be equal
to the correlation of mother's IQ with grandmother's conferring ability (20%
at most), times the correlation with mother's conferring ability (50% at most
and probably much less), times correlation of mother's conferring ability
with baby's IQ (20% again) . That's less than 2%, possibly much less.
You'd never see it, even if it's there. Further, a lot of studies separate
out the pre-natal effects so *of course* they
don't show more input from mom's genes.
There is *no* requirement for sexual dimorphism for imprinting. There's an
association, because dimorphism in parental care provides opportunity for
conflict between parent's genomes about the offspring's demands. But if the
goal is offspring benefit apart from exploiting the other parent then a
non-dimorphic species would do it just as well. Even asexual mothers
manipulate offspring freely, as with production of the sexual morph in
cyclically parthenogenic Daphnia, or sporulation in [pick a species]. So the
"sex differences provides an opportunity for rapid mammalian evolution" is a
castle built on air.
The business of mitochondrial transmission of IQ through the father is
bizarre. We've never seen paternal mtDNA in a human, ever; plus the genome is
so tiny there's no room to have much going on. Fathers *do* imprint, but
only on nuclear genes, as far as we know.
Sorry to be crude, but this sounds like the attempts of a high-IQ male myope,
possibly Jewish, to justify himself as the ultimate in human evolution to
date. He's bending a lot of science to claim particular groups produce
super-sperm, basically, and I'll bet he's a member of those groups.
If somebody came up with some evidence of imprinting/ parental effects in
myopia or IQ, I'd be interested, but this isn't it. I'm mildly curious about
all the myopia variances but it's patently obvious the studies aren't very
comparable/well controlled. IMO it's probably something like whether
toddlers get read to. E.g., desparately poor Indian parents don't read to
their children and so the children are only myopic with extended close work.
Myopic (and usually middle-class) parents do read to their children so they
get a "head start" on myopia. Additionally, if parents can't afford
eyeglasses there are limits to how myopic the children will get.
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