Do Biological Clocks Revive William Paley's Design Argument?
A primary criticism of William Paley's "watchmaker argument" for a designer is that organisms are vastly different from man-made machines. What then should we say about ongoing discoveries of mechanisms in living cells that not only keep time, but do it more elegantly than anything man has invented?
It is commonly assumed that David Hume and Charles Darwin demolished Paley's watchmaker argument. Intuitively appealing as it was, the idea that a "watch demands a watchmaker" is fatally flawed, or so 20th-century students were taught. Paley's work was an argument from analogy, an unwarranted extrapolation, a science stopper. It ignored the history of organisms and the many dissimilarities between living things and machines.
Darwin, by contrast, provided a mechanism, uniting contingency with natural law, that could produce complex design without a designer. This rendered Paley's watchmaker superfluous. Dawkins made this argument the theme of his book The Blind Watchmaker. Christian de Duve argued in The Nature of Nature (pp. 349-350) that pliable proteins bear little resemblance to rigid mechanical parts in machinery; further, design arguments fail to take into account "the time element."
It's understandable that we today might want to distance ourselves from Paley. His arguments were anecdotal, lacking the rigor expected of later Victorian science. He tended to extrapolate and exaggerate the designs he saw, finding a benign purpose in just about everything, practically inviting critics to come up with counterexamples of harmful design.
Furthermore, in attempting to defend the Christian deity from the observations of nature alone, without reference to Scripture, he placed more weight on the evidence than it could bear. More importantly, living over a century and a half before the earth-shaking revolutions in molecular biology and genetics, Paley could only speak about the appearance of design at a gross macro level.
Nevertheless, Paley's pithy story of finding a watch on a heath retains its quaint appeal. Paley's watch is intuitively compelling to the non-scientist and understandable by children. It appears to comport with everyday experience. Darwinism, by comparison, is abstruse, requiring lengthy explication, as if its proponents need to explain away the obvious. That alone doesn't make it wrong, just rhetorically more challenging; Darwinians are stuck in the role of Groucho Marx, "Who are you going to believe, me or your own eyes?"
Meanwhile, however, new discoveries are conjuring up the ghost of Paley once again, suggesting his argument never really died. These discoveries involve biological clocks. That's right: clocks.
It's old news that plants and animals are well adapted to diurnal cycles. Only in the last decade, though, have biochemists peered into the black box of timekeeping mechanisms that calibrate, synchronize and maintain life's circadian rhythms. What they are finding bear the hallmarks of Paley's watch: structures, mechanisms, circuits, feedback loops, and sometimes even batteries and gears. Two recent papers illustrate the point.
In Science on May 31, Huang et al. described two proteins that, together, calibrate the body's internal clock to the day-night cycle. Called CLOCK and BMAL1, these proteins act as a kind of battery for the biological clock. ScienceDaily actually said this, quoting one of the authors who stated, "CLOCK and BMAL1 are really the batteries of the biological clock." The paper used the word mechanism six times, but Darwin, evolution and natural selection zero times.
Another paper, in the May 31 Current Biology, announced, "An intricate neural circuit composed of multiple classes of clock neurons controls circadian locomotor rhythms in Drosophila." This paper was similarly consumed with machine language -- circuits, structures, mechanisms -- but had nothing to say about evolution or Darwin. Another paper in Science from October 31, 2008 actually spoke of cogs and gears in biological clocks -- of bacteria! These illustrations are not atypical in the field of circadian rhythms. They raise stimulating new questions about whether announcements of Paley's demise have been premature.
Consider, for instance, if Paley had found a frog on a heath instead of a watch. Examining it with the tools of 21st-century biology, suppose he observed that it had structures, mechanisms, feedback loops, circuits, cogs and gears all related to timekeeping. Would this not undercut his critics' assertions that living organisms differ substantially from machinery?
Michael Denton recognized this possibility 27 years ago. In Evolution: A Theory in Crisis (1985, p. 341), with full knowledge of Hume and the other critics of Paley, and the inherent weaknesses of analogical arguments, Denton recognized that developments in molecular biology, particularly the intricacy and perfection found in living cells, were strengthening Paley's argument for design and undercutting the Darwinians' argument that natural selection rendered it superfluous:
It is interesting to speculate how the theory of natural selection might have fared in the nineteenth century had the analogy between the living and mechanical worlds been as apparent then as it is today. The depth of the machine-organism analogy would have more than satisfied William Paley, and would certainly have provided Darwin's antagonists with powerful ammunition with which to resist the idea of natural selection.To underscore why the analogy is so much stronger now, and more compelling, we need to discuss briefly the concept of instantiation. Consider money: it can be instantiated in a variety of ways -- in coins, paper, clams (remember the comic strip "B.C."?), cattle, electrons (electronic funds transfer), or even in promises and gestures, like collateral or a handshake. Temperature, likewise, can be verified by a mercury thermometer, a thermocouple, a bimetallic strip, a laser, or by the sensations on your hand. Similarly, a clock can be instantiated by a water clock, a sundial, a wristwatch, a pendulum, an atomic clock, or a biological clock.
This undercuts de Duve's argument that squishy proteins are far different from rigid mechanical parts. If they work to keep time, if they operate like cogs and gears, who cares what they are made of?
One more consideration threatens to revive Paley's ghost and scare the living daylights out of the Darwinists: the collapse of their historical argument. Living things, they say, have an evolutionary history that could produce complexity from simpler beginnings by natural selection. Well, both recent papers cited above said that similar mechanisms exist in mammals and fruit flies. The common ancestor of these are so far down Darwin's tree, it leaves evolutionists with two options: (1) the complex biological clock mechanisms had to already exist in the common ancestor, begging the question of how they arose, or (2) the mechanisms arose by "convergent evolution" -- a post hoc rationalization that assumes what it needs to prove.
Let's imagine Paley's great-great-great grandson (if he has one), with full awareness of Darwin's theory, was walking across the proverbial heath one day and found a mouse with a fruit fly on its back. Using the tools of 21st-century molecular biology, suppose he observed similar mechanisms in both, composed of precision parts interacting for the function of keeping time.
Would he not be justified in claiming his famous forefather's design argument was even stronger now, not only because of the similar specified complexity at work in the timekeeping function in both, but knowing they were so divergent in Darwin's tree as to render implausible the notion that they arrived at similar design solutions via unguided processes operating on independent historical trajectories?
Yes, it's true that Paley didn't adequately deal with dysteology. He pressed his analogy beyond a deductive argument, and was motivated to corral evidence to support his belief in the God of the Bible. In fairness to Paley, though, we should read his own words.
William Dembski has called Paley's Natural Theology "one of the great unread books" (No Free Lunch, p. 31), implying that some Paley critics may be attacking a straw man. Understood as a product of its time, it remains an invigorating read that can impart some wisdom even today.
Image credit: Leo Reynolds/Flickr.