In <71cqlh$gol at ux.cs.niu.edu> rickert at cs.niu.edu (Neil Rickert) writes:
>>"Ray Scanlon" <rscanlon at wsg.net> writes:
>>>Of course, the environment is part of the equation, I never said or
>>otherwise. With a specific person, we may speculate on the relative
>>importance of DNA versus environment and that too is interesting. I
>>exception when people say that the brain is fundamentally different
>>pancreas, that DNA does not construct both.
>>The DNA does not construct either the pancreas or the brain. DNA is
>a set of specifications for making proteins. A blueprint does not
>construct a house or anything else, but carpenters and bricklayers
>may use the blueprint in carrying out their construction. DNA
>doesn't construct anything. The machinery of the living cell
>constructs, and uses the DNA in the construction.
>I suspect that Ray understands what you are TRYING to say, better than
you do yourself. Certainly, I do.
Homunculus reinvented? The little-man-in-the-cell "using" a blueprint
while IT ("he") constructs more cells and eventually a person?
Poor metaphore. How about this one (it has its own flaws, but at least
it is different): is the cell like a computer "using" DNA like a
program? or is the program "using" the computer? (Not QUITE the same
question as "is a chicken an egg's way of making another egg?", but
reminds me of it...)
None of these metaphores does justice to the complexity and elegance of
the process. At each stage, the organism is the outcome of an
interaction between the organism's elements within its internal
environment (including its DNA) and between it and its external
environment. The DNA remains (relatively?) stable and unchanged
throughout all these interactions, but of course which portions of its
information are acting on ITS environment (or is being "accessed" by
it) changes froom moment to moment.
re relative amount of influence: the question makes as much sense as
asking which contributes more to the area of a rectangle--the height or
the width? (not ooriginal; forget who said it first--Hebb??? about that
More about identical twins and the power of the environment: I used to
draw cartoon diagrams of a striated muscle cell, a red blood cell, and
a nerve cell on the blackboard, and then tell my students that these
were identical siblings that grew up in different environments. (true)
Of course, you could also use this to demonstrate the versatility of
that very smart DNA--able to produce such diverse offspring, to meet
the demands of different environments, not just a mindless "blueprint"
for the cell's "use".
Bottom line: no substitute for the painstaking moment by moment
analysis of develomental interactions. Those who undertake this
analysis are not the strawmen Rickert imagines.
(Bytheway: just what IS his point, anyway? In 50 words or less.)
F. Frank LeFever, Ph.D.
New York Neuropsychology Group