A comment about complexity in another post (Complexity, last paragraph) made me think of two of the most overused arguments in the creationist playbook — the complexity of the human eye is impossible to explain through evolution and “If you were to find a watch on a path, would you conclude that the watch ‘just happened’ or that it was designed?”.
The first question has been adequately answered so many hundreds of times (many of them on the Internet, like Evolution_of_the_eye), that I won’t bother doing it again. The watch presents an interesting opportunity that is often wasted. Why a watch and not a beautifully sculpted statue? The difference is that a nineteenth century pocket watch was complex as well as demonstrating craftsmanship. If you’re talking about the artistry involved, the analogy to nature falls apart, so the real question has to be about complexity. Here is William Paley’s argument (published in 1802).
In crossing a heath, (…) suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place; I should hardly think of the answer I had before given, that for anything I knew, the watch might have always been there. (…) There must have existed, at some time, and at some place or other, an artificer or artificers, who formed [the watch] for the purpose which we find it actually to answer; who comprehended its construction, and designed its use. (…) Every indication of contrivance, every manifestation of design, which existed in the watch, exists in the works of nature; with the difference, on the side of nature, of being greater or more, and that in a degree which exceeds all computation.
This is now a slight variation of Michael Behe’s “irreducible complexity” argument where if any part is removed, the device no longer has any use. I have answered Behe’s mouse trap challenge earlier by repeating the argument showing that you can remove parts of a mouse trap all the way down to only having a spring remaining, and you can still have a working mouse trap. The arguments are here (McDonald’s Mousetrap) and here:
The more usual case for evolution is that a part of a living being that serves one function (feathers for insulation) may take on a new function (flying) when combined stepwise with other pre-existing features.
There is a major difference between evolution and design, and that is that design is intentional while evolution just muddles along making occasional changes, and those that create an advantage to preservation of a population of genetically similar entities are inherited and spread throughout the population, and those that are disadvantageous die out. Darwin spent much of his time demonstrating the haphazard construction of living things that would never have been done that way by a competent designer.
Now it’s time to return to the watchmaker. First watch this video that explains how inept the analogy is between a clock and living things, followed by what would happen if components were capable of affinities that would simulate life.
The real question in this whole mess of inappropriate analogies is what was the source of the design? Historically, we know that pocket watches didn’t suddenly appear because someone in the ancient past decided one day that the world needed a portable timekeeping device. The purpose of a watch is to calibrate time, and that requires measuring something that happens at a constant rate. Water clocks, hourglasses, and calibrated candles are simple examples.
Water clocks were particularly amenable to mechanization. In India, floats measured the passage of time, and in China, Greece, and later, the Islamic world, geared mechanisms were able to extend measurements to protracted periods of time, as well as breaking the continuous process into intervals. The Greek Antikythera mechanism (from 150-100 B.C.E) is particularly renowned (Antikythera Mechanism). Al-Jazari’s castle clock of 1206 C.E. was considered an early example of a programmable analog computer. Segmental and epicyclic gearing were in use by the very early 11th century in Iberia, and the escapement mechanism (the thing that ticks in a watch and powers the time-measuring components) was in use around the late 11th century in China as a means to maintain constant water levels to improve the accuracy of the clocks.
A clever system that may have predated the 13th century was used in conjunction with water clocks to ring bells at certain hours. It was the crown wheel and verge alarum mechanism partially pictured below.
Hammers were attached perpendicularly to the verge bar, and as the verge oscillated back and forth, the hammers struck a bell.
These wonderful mechanisms were developed over many centuries, but the flow of water is not nearly consistent enough for really accurate time keeping. Among other things, its viscosity changes with temperature (when it’s not frozen), and maintaining a water supply is a nuisance. By the late 13th century, an entirely mechanical device was invented that created fairly consistent time intervals, and it was installed as early as 1283 in the Dunstable Priory. The mechanism is called a verge and foliot escapement, pictured below.
Verge and foliot escapements were used as late as the 18th century in pocket watches! The time interval of the escapement could be adjusted by moving the weights in or out along the foliot bar, but even with adjustments, the best clocks were only accurate to within 15 minutes a day and had to be reset daily using the position of the sun.
This next innovation was a result of Christianity, as much as I hate to admit it. Galileo noticed a swinging chandelier in the Pisa cathedral in 1582, and that the timing of its swing seemed independent of the amplitude of the swing (which is not true of a foliot). In 1602, he began experiment with pendula and determined that for small amplitudes that this was correct (along with other results). Christiaan Huygens used this observation to replace the foliot with a pendulum (shown below).
His clock improved the accuracy of mechanical clocks to about 15 seconds a day.
As early as the 14th century the foliot was sometimes replaced by a wheel (called the balance wheel), which improved air resistance, but did little for improving accuracy since the time interval was still controlled by how far the foliot or wheel traveled during oscillation. In 1658, Robert Hooke fixed this problem by adding a spring to counter how fast the verge was throwing the balance wheel, and in 1674, Christiaan Huygens (again) replaced that with a spiral balance spring similar to what is shown below.
Again as with the pendulum, the wheel with the balance spring oscillates with a constant time interval, no matter what its amplitude.
The biggest remaining problem with accuracy are the crown wheel and verge. In quick succession, the anchor escapement was invented by Robert Hooke in 1660, and the deadbeat escapement improved that and was designed by Richard Towneley in 1675. They look similar and are pictured below.
Several other refinements occurred, the most popular of which was the lever escapement invented by Thomas Mudge in 1750 and used all the way into the 20th century (shown here with a modern balance wheel).
Now we have all the components for that pocket watch that Paley found on the heath, but the design had to evolve through many stages and iterations before reaching a stage that he would recognize as a timepiece, much less, one that would fit in his pocket. As creationists who want to throw abiogenesis, the big bang, stellar evolution, and cosmogenesis into biological evolution are so found of claiming, we must recognize evolution in all its forms.
I hope you enjoyed the journey.