Thursday, May 24, 2007

TELOPHOBIA

Here’s an example of telophobia (fear of teleology) in contemporary science writing, from "The Ages of Gaia" (Bantam, 1990) by James Lovelock (Pseudomonads are microorganisms that produce macromolecular nucleation sites that cause water droplets to condense from the atmosphere):

"Pseudomonads have an ancient history, and maybe their ice-nucleation trick goes back to the Archean. If so, were they the rain makers that led the colonization of the land? A question that always arises at this point in speculation is: How did it happen? Surely the bacteria did not decide to make the ice-nucleating substance. At this point, serious–minded microbiologists grow anxious and fear the proximate occasion of teleological heresy. Fortunately, we can easily make a plausible model of the evolution of close coupling between a large-scale environmental effect and the local activity of microorganisms—a model, moreover free of any taint of purpose."

He goes on to make the case that the ability to freeze water must have benefited the ancestors of extant pseudomonads and that the talent therefore spread from generation to generation of the microorganisms. The effect of rain on later evolution is merely incidental. (Try to imagine what the Earth’s biosphere might be like if rain was an occasional atmospheric quirk rather than an ecological driver.)

Lovelock might be more sensitive to accusations of "teleological heresy" than most scientists, because early criticism of his Gaia concept targeted Gaia’s teleological implications. Nonetheless, nature is perfectly capable of executing plans, as happens every time a fertilized ovum matures to adulthood. Don’t plans serve purposes?

In fairness to Lovelock and other telophobes, then, "taint of purpose" needs a clearer definition. Purpose might be defined in a limited way, in terms only of human ways and means, in which case no scientist need fear the teleological heresy when describing nature. Alternatively, it might be sensible after all to assign purpose to all kinds of cause-and-effect sequences in nature. What exactly is it that Lovelock thinks might make microbiologists uncomfortable?

If we ask a computer programmer about a section of code, she might tell us that that section of code ensures that when a particular dialog box appears on a user’s screen it contains data pulled from a particular field in a particular database, so that’s the purpose of that section of code—to make that data appear in the right place at the right time. It seems straightforward.

Now, if we ask a geneticist about a section of DNA—genetic code—and he tells us that that section of code ensures that a particular protein contains a particular amino acid at a particular position in the sequence of amino acids, we might in this case be less eager to say that the code has a purpose, for fear of committing “the teleological heresy.”

But in both cases a coded sequence contributes something necessary and specific to a larger program. Purpose is granted in the one case; but not in the other. Might the relevant concepts be too imprecisely defined? Let’s see if we can achieve clarity by scrambling them even more.

Let’s say that DNA hackers drop new genes into the genome of a variety of tomato and that the new genes ensure that the fruits of the plants contains large amounts of caffeine, or sugar, or [insert favorite substance]. In this case some of the genes in the revised tomato genome have a purpose, but the rest do not?

Here’s a sequence of genes. Look it over carefully. Which ones have purpose?

What if the sequence of inserted genes incorporated some genes from the original tomato genome—then would those genes be transformed from being purposeless to being purposeful, even though they correspond to the same amino acids after the insertion as before? This thought experiment should serve as therapy for anyone suffering from telophobia.

Maybe the problem gets fixed if the operative term is changed from purpose to function.

Is the function of a thing merely whatever the thing can be observed to do—or only what it is intended to do? The function of a jet engine is to propel a plane. But the engine also produces heat. That is not its function, though the function of some devices is precisely to produce heat. It looks like function is a function of human intent. This is a troubling observation, because it means that although we observe nature doing things, nothing in nature has any function whatsoever. The stomach makes food suitable for passage through the intestine. Do we really want to say in the next breath that stomachs have no function—serve no purpose?

The terms attached to teleology: purpose, meaning, function, code, plan, program, information—these all are problematic concepts, because they subside in the no-man’s land between science from religion. And for that they hold the promise of a reconciliation of the mighty ideological antagonists.

Scientific telophobia is understandable, given the vagueness of the terms that carry the "heresy of teleology." An unwary scientist might too easily step off the nihilistic path of scientific orthodoxy into a pile of sentimental/superstitious teleological goo. But the solution to the teleological conundrum is not to cast meaning, purpose, etc., into the wilderness, but to give precise operational definitions to these problematic terms.

Just thinksomeday we might actually know what we're talking about. Nah.