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Are there "Identical Twin" plants?

Andrew Dalke dalke at acm.org
Sun Dec 17 02:38:14 EST 2000

George Hammond wrote:
>     For instance, if you had 3 brand new cars Volkswagon,
>     Mazzeratti, and plymouth; it is known that the top
>     speeds under perfect conditions are 85, 165, and 100.

How do you know that?  Take 3 different Volkswagons off
the production line and they will all have (slightly)
different top speeds.  In one the spark plug gaps was off by
a bit.  In another, the tires are slightly flat.  In the
third, the oxygen sensor was somewhat blocked.

Some of these might even compensate for other problems.
If the oxygen sensor is bad you might get a higher top
speed with "bad gasoline" because the two effects cancel
each other out.

At best you could get a good mechanic to come in and fix
things then see how fast it goes.  There's still the wind
and the roughness of the road, and the atmospheric density
and other parameters affecting the top speed.

Do this enough times and you might be able to extrapolate
from that the top speed is around 85, but that will only
be an estimate and there's nothing to say that on the right
day you might get lucky and break 86.

This is relevant to your question because you earlier asked
if there was some limit to plant size while here you assert
without justification that such a limit not only exists
for cars but is easily quantifiable from its design.

>     Now fill all the tanks with "bad gasoline", and we
>     find the top speeds to be  60, 130, and 80.  This
>     indicates a "performance deficit" of 25, 35 and 20
>     respectively.  The bad gasoline is a "nurture" effect,
>     while the difference in the original top speeds is
>     the "nature" (or genetic) effect.

Arguing by analogy is almost always troublesome.  Consider
the opposite case of using "good gasoline" (a higher octane?
nitrous?)  Couldn't that make a car go faster than the factory
rated speed of 85?  Perhaps the "nurture" effect can make
the car perform better than the "genetic" effect from the

Similarly, plants may grow a lot bigger if given, say, 15 hours
of light per day all year rather than the 12 hours average
they get now.  If your estimates on limits did not take into
account these possible non-natural environmental influences
then would that mean the plants exceeded their genetic makeup?

(In my previous response I mentioned that some plants to better
when more CO2 is present.  That doesn't occur naturally now,
but the experiment was done to see how plants might do in
a possible greenhouse-effect earth.  I bring this up again to
point out that a lot of possible variations on plant size are
not tested, so extrapolations of existing experiments will
not necessarily point out a definite maximum.)

>       We should be able to do the same thing with plants.
>     What I'm trying to demonstrate, is that there is a
>     universal "bad environment" effect, whereby, NO PLANT
>     ever reaches it's "genetic top speed"... it's
>     "genetic full growth" as it were.

And I argue that such a statement is so broad as to be useless.
There are no plants, animals, bacterial, archeobacteia,
minerals, clouds, planets or freckles which can ever exceed
its "natural" limits.  The only time you can reach the limit
is to have no variation - there are no 2 proton hydrogens
because hydrogens only have 1 proton.

Can Mozart create a symphony which cannot be created by Mozart?

                    dalke at acm.org

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