Evolving Thoughts

Evolution, culture, philosophy and chocolate! John Wilkins' continuing struggle to come to terms with impermanence... "Humanus sum, nihil humanum a me alienum puto" - Terence

Saturday, May 21, 2005

Confusing the medium with the message

It has been reported at Wired that the American Diabetes Foundation has set up a "virtual" lab rat to test diabetes cures. Actually, it's a non-obese diabetic (NOD) mouse, but that sounds less cool.

Traditionally in diabetes research, they have used mouse strains with certain genes knocked out to test the effects of diabetes. The antivivisection lobby has in the past claimed that we can use computer models of organisms instead of real animals. This appears to show that we can do this. Expect calls for the replacement of organisms with computer models in medical research soon.

But this is misleading. It only works if the relevant aspects of the organisms are extremely well understood, and there are no confounding factors. A model is only as good as its representativeness, so to speak. And organisms are much more complex than any simulation - in the end, some experimental work will need to be done. There are no shortcuts. And for the NOD model, a lot of experimental work needed to be done before we could even begin to consider using it in research. Perhaps it will work - if so, it's because we already know what we need to know to make it work.

This is part of a much wider confusion, I believe, in science and generally, between the models and descriptions, which are abstractions, and the things in the world that are modeled and described. An organism is not an abstract system. It is very physical, and it differs in detail and occasionally in larger ways from its relatives and nearest species. And any one of those differences can, well, make a difference.

Suppose that we do figure it out well enough to model the pathways that lead to diabetes. A "cure" is delivered based on that model. Are we done? Not at all. Knowledge is not delivered in neat textbook examples, but in the interplay of those who have it and the things known about. It may be that the cure affects growth rates, or neural development, or the propensities of the organisms to develop pancreatic cancer. How can we know this? By observing the effects upon real, not model, organisms. And that either means humans, someone's children or spouse or parents, or it means model animals. Mice, rats and so forth. The very things the model is supposed to replace.

Don't leap to thinking that the medium - the model - is the message - the organism. Just as abstract things aren't concrete, abstract cybernetic systems are not the same as concrete organic systems. The Harvard Rule - that under carefully controlled conditions the organism will do as it damned well pleases - must always be borne in mind.