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Ray Scanlon rscanlon at wsg.net
Fri Oct 30 09:10:03 EST 1998

Jim Balter wrote in message <36395A34.4F58BF9F at sandpiper.net>...
>Neil Rickert wrote:
>> My disagreement is that you seem to have been making claims which
>> discount the signal energy and put the DNA in charge of everything.
>> However, you are also ignoring other sources of variation during the
>> development process, which have effects other than through the signal
>> energy and DNA.  For example, how well nourished the child is will
>> also have effects on development, including neural wiring.
>In fact there are cases of identical twins where one has a brain and
>one doesn't.   Scanlon's claim that identical twins have identical
>neural topology is a matter of quasi-religious dogma contrary to fact.

Good Lord, did I say that? My mind must be slipping, I will be 77 next
month! I have never heard of a scientific investigation of the brain wiring
of identical twins as opposed to fraternal twins or the population in
general. I would very much like to hear if someone has done it and how they
did it.

I do suspect that because of the way in which DNA constructs the body that
the brains of identical twins would resemble each other in the same way that
hair color, height, and body proportions resemble each other. But that is
just idle speculation on my part. I repeat: idle, idle, idle speculation.

In particular, I am not pushing any religious dogma, quasi- or otherwise.

The nucleotides in DNA make codons in mRNA and the human body results,
teeth, esophagus, and brain. I don't preach it, I just marvel.

Of course, the environment is part of the equation, I never said or thought
otherwise. With a specific person, we may speculate on the relative
importance of DNA versus environment and that too is interesting. I do take
exception when people say that the brain is fundamentally different from the
pancreas, that DNA does not construct both.

On the question of signal energy. Of course it is important, overwhelmingly
so. The DNA sets up the rules for the general wiring and incoming signal
energy alters the fine structure of the brain. That's the way it works, is
this preaching? Hubel and Wiesel demonstrated this over forty years ago,
it's time we all accepted it.

Those interested in how the brain works might look at

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