A reply to Frank Bruggeman
Personally, I think a lot depends on your definition of the word
"Theory". It seems to me that the central statement of the metabolic
control analysis theory, that control is shared between steps, is
moderately falsifiable. If a large number of pathways were analyzed
and all would have a single step with control coefficient 1.0 this
would falsify the theory. What if roughly half of all pathways would
have a single rate controlling step? It seems to me that the best is
to take Hans Westerhoff's definition: MCA is indeed a tool and the
theory it is based upon is the MCA theory. As long as it works
something about it is right.
> Therefore I'm inclined to think that MCA is not a theory but a tool and
> therefore its MCA and not MCT.
>> Can anybody think of a way to falsify MCA?
> Can anybody make an argument why MCA is a theory even though not
> falsifiable?
> Are there examples of similar theories?
A great example of a theory becoming an approach, not even a tool in
the strict sense, is the Gaia Theory of Lovelock. This theory was
indeed falsified, but still provided a very good angle to look at
earth system science. Gaia science nowadays looks at the interaction
between life and the dead matter of the Earth, but the original idea
of homeostasis has been abandoned. The many feedback systems that are
being discovered in the process, both positive and negative, remain
an exiting subject for research.
Best regards,
Benno
Benno ter Kuile
Leiden Institute of Chemistry, Gorlaeus Laboratories.
Leiden University;Einsteinweg 55 / P.O. Box 9502 2300RA, Leiden, The Netherlands.
Phone: +31 71 5275272 TeleFax: +31 71 5274537
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