> He [Greg Petsko] pointed out that TIM barrels (a fairly
>common protein fold) is the architecture for several different enzyme
>mechanisms. Knowing the fold only leads us to a set of several and often
>very diverse possibilities. Then he made the outrageous claim that knowing
>the function tells us little or nothing about the function! The point was
>that many proteins have multiple functions and that knowing one function
>still leaves us in the dark relative to the other functions. Crick's
>dictum is no longer good enough, Petsko said. Study function, but if you
>can't study function ... well ... don't study. He then urged us not simply
>to train structural biologists, but structural biologists who are
>interested in function and who can and will use all the repertoire of the
>methods of biology to understand function.
As a non-biologist, I would like a clarification of language here. It seems
to me that if someone is a thoroughgoing Darwinist, he will avoid all
language that is teleological. Isn't the concept of function teleological,
just as the notion of 'design' is? In the context above, to 'study function'
seems to mean, 'find the purpose for which this molecule is used.' But
if biology as a whole is really devoid of purpose, then how can its
components be said to have a purpose?
I have noticed many such instances in the use of the words 'function'
and 'design' in articles in Science and Nature recently. Are the
biologists simply being sloppy, or is it the case that we are
linguistically unable to describe biological phenomena in any other terms?
Paul Arveson, Code 724, Research Physicist, Signatures Directorate
Naval Surface Warfare Center, Carderock Division
9500 MacArthur Blvd., West Bethesda, MD 20817-5700