The teleology that dare not speak its name

I’m a bit remiss on posting at the moment – partly that’s because of music commitments, and partly, maybe, because I’ve lost the stimulus of BioLogos, which seems to have blocked all my comments since the start of the new year and which hasn’t responded to my querying e-mail. But there you go.

There’s a textbook example in the popular press today of how things in biology make perfect sense without evolution, but it gets dragged in gratuitously anyway. I heard it on BBC news, and it’s in all the British dailies, though the original short article was published in Biology Letters as an MSc project. Its public appeal seems to be based on the life-changing fact that it seeks to explain why your fingers and toes get wrinkled in the bath.

The research was prompted by the discovery not too long ago that the wrinkles are not caused by osmotic swelling, as was supposed, but by an autonomic vascular mechanism. That observation was science, but the (perfectly justified) response of the present researchers immediately departed from science’s methodology and asked, “What is that mechanism for?” In other words, teleology was the sole connection between the observation and the experimentation that followed.

If science were theistic, it would be reasonable to ask “Can we deduce why God has made us so fearfully and wonderfully in this respect?” But since it is not, and purpose cannot lawfully be admitted, the only valid scientific questions would really be, “How does this autonomic response happen?” and “What efficient causes led to it?” But we’ll let the researchers off, because the interesting question, as they rightly agreed, was actually the unscientific one: “What’s this for?”

The distinction matters because that last question was, in fact, the only one to which their research offered any answer at all. They showed that wrinkled fingers are better at handling objects underwater, and equal to unwrinkled fingers in handling dry objects. So there is an association between wrinkles and handling ability, which may suggest why God made us that way, though a functional connection is at best tentative. After all, other explanations are possible: a visual signal to get out of the water, for example. And their only accounting for wrinkled toes was based on an experimentally unverified speculation that toes may plausibly grip better underwater too and that this is a benefit – personally I’d rather my toes became webbed when wet so I could swim better. They did no work actually to explain how grip is made better. So the sole, rather modest, conclusion to be made from the evidence they give is that because we believe, against methodological naturalism, that physiological mechanisms are there for a purpose, increased underwater grip might conceivably be the fin‌al cause for this one.

Vaguely aware, perhaps, that teleological science isn’t really science, the article’s final couple of paragraphs drag in the obligatory evolutionary element. When one of the workers was interviewed for BBC Radio 4 news today, this was actually the main point of the story: “Evolution explains wrinkled fingers.” But of course it does no such thing. The evolutionary “science” was no more than a tale that “no doubt” this function arose in one of our anonymous ancestors because it “may” have conferred an advantage in walking in mud or in handling things underwater. The researcher didn’t mention that it is statistically more likely from neutral theory that it arose independently of selection and just happens to be there – it may be no more an explanation of anything than the resemblance of a random potato to Barack Obama would be.

The article itself “explains” that we are not wrinkled all the time because there could be some as yet unknown disadvantage to that. Carrying on in Kipling vein, the guy on the news suggested that the wrinkle response still persists in us non-aquatic humans either because it still confers some evolutionary advantage or because there has been insufficient selective pressure for it to disappear. Which begs the question why there was ever sufficient selective pressure to explain its development in the first place. But there is no scientific data available with which to address that question – no actual measurements of advantage or disadvantage (or even how one would measure such a thing), no actual knowledge of which animals display this reaction and which don’t, or when it may have appeared, or whether there’s any connection at all with those species that gain enough of a living from working underwater with wrinkled digits to affect their survival one way or another compared to animals that sensibly take their limbs out of water when they’re not working.

The whole story, in other words, is that evolution (the only authorised process) might have produced an observed physiological mechanism either by selection or drift, which may or may not functionally affect grip underwater enough to have conferred, now or in the past, some degree of advantage. And all that froth comes from a modest experiment based on the unacknowledged conviction that teleology does actually occur in nature.

The acknowledged conviction, that evolution is the explanation of the whole thing, could easily replaced in the article by a statement about apple pie and motherhood, or a plea to support Manchester United, for all it contributes to the science presented.