I have been reading for at least the second time, maybe the third, Richard Dawkins’ magisterial book about evolution, The Greatest Show on Earth (hereafter Show). Like the other one or two times I have read Dawkins’ book, it was an exhilarating ride. Until I read the appendix, which pertains to how the theory of evolution is, to this day, received in the US and non-Scandinavian Europe. That appendix to Show is a real downer. (I reacted similarly when I first read the book.) It turns out that, even in the supposedly enlightened First World – again, the Scandinavian countries are the blessed exception -- around 80% of respondents accept a theory of evolution that accommodates some kind of supernatural explanation, e.g., God did it all according to a literal reading of Genesis, chapter 1; or evolution was a mixture of natural law leavened with Divine intervention. (Dawkins is quoting statistics from the Pew Foundation’s survey of religious beliefs / attitudes.) Only about 14% of respondents in the US, and a comparable percentage worldwide, outside of Scandinavia, subscribe to Dawkins’ (and my) position of evolution as a purely naturalistic phenomenon.
The reasons for this incorrigible skepticism are dauntingly complex. But one conventional response justifying rejection of evolution that crops up time and again, both in my personal experience and in the literature, is that evolution purely through mutation and natural selection with no admixture of Divine teleology is, to use a recurring phrase, just too “random” to account for the awesome variety and complexity of life we find on earth. People who believe evolution is a random process see evolution as analogous to putting many handfuls of very sticky marbles, representing chemical elements and organic compounds, into an empty coffee can, snapping shut the lid on the can, and then shaking the can vigorously for perhaps 4 billion years. (The time issue is another sticking point: many of the more conservative respondents were “young earth” creationists or intelligent-design advocates. In that sense, and assuming such constricted time-frame, Divine creation or intelligent design would probably be a compelling alternative: 6,000 or 10,000 years would not allow nearly enough time for speciation by naturalistic mechanisms. Some Deity probably would indeed have to stacking the deck in favor of the appearance of intelligent life. But this is a rant for another time.) The problem with this view is that it equates random processes with chaotic processes (keep reading). This is one of those subtleties, one of those nuances, that most conservatives usually skate over, but that is the key to the entire question.
In fairness, we should concede up front that randomness does play an important role in evolution, and that it does so in two ways. First of all, yes, the origin of life is most likely accounted for by random occurrences. No one knows how life originated. There are lots of theories, but no one knows. E.g., there is the so-called “clay life hypothesis” of Graham Cairns-Smith that many find compelling. I am not enough of a paleontologist or evolutionary biologist to even venture an opinion on that. “Clay life” is one theory among many, and like all such theories of origins, it invokes randomness as a primary construct. Secondly, once life is “up and running,” even at the sub-cellular level, randomness enters in from influences of the physical environment. Long-chain molecules of “proto-DNA” are bombarded by, e.g., cosmic rays, left-over radiation from the decay of radioactive material in the earth’s deep interior, changes in ocean and air chemistry, etc., etc. (Again, this is after life is “up and running.”) The material of life is altered at that deep level – hence mutations – and most of these mutations are maladaptive (i.e., diminishing the chances for survival) and so are selected out as evolution proceeds. (Considerably more than 95% of species have been forced to drop out of the march of evolution by such environmental pressures.) Note that, e.g., which particular base pair will be disrupted on which particular DNA molecule by, e.g., which particular cosmic ray s a purely random event, impossible to predict, even in principle. So randomness does play an important role in what might be termed “micro-evolution”. (Also in “macro-evolution,” e.g., which asteroid will collide with earth at what time, when the “Siberian traps” will erupt during the end-Permian era 250 million years ago, etc. But again, that is another rant for another time.) But conservative critics of evolution, while they have a valid point about the role of chance in evolution, then overreach by attempting to use randomness to discredit evolution as a whole, evolution tout court, evolution as such.
I say this is an “overreach” by conservatives because of the implicit assumption that any phenomenon that cannot be exhaustively characterized by a set of (perhaps quite complex) predictive equations is therefore random. I.e., they assume that there is nothing intermediate between true randomness, which is inherently unpredictable, and rigorous, mechanistic phenomena that are exhaustively predictable. Ever since the 1970s, perhaps before, the fallacy in this reasoning has been abundant. Some classes of phenomena are neither rigorously predictable nor purely random. These intermediate processes are usually called chaotic. (If you want to read an excellent non-technical book about chaos, you can do no better than James Gleick's Chaos: The Making of a New Science. A rather more advanced introduction, neither for the faint of heart, would be the by-now-near-classic From Being to Becoming or Order Out of Chaos, both by Ilya Prigogine.) The difference between chaos and randomness is subtle but critically important. Chaotic phenomena are quite lawful, i.e., anything but random, but notwithstanding are not exhaustively predictable. Consider the following example of a chaotic phenomenon.
Think of the game of chess. Now, as a chess player, I am a wonderful garage mechanic. But even I know enough about the game of chess to realize that the number of possible chess games two people can play is, for all practical purposes, infinite. I.e., not literally infinite, but so large that even writing down, in fixed point notation, the number of possible chess games that could be played would be so large that just writing down the number of possible chess games, move by move, in digits would probably require that all the trees that have ever lived on earth be converted to paper, and probably all the alien quasi-trees that may exist on all earth-like planets in the Universe. Even using exponential notation like N x 10M might not suffice, because there would be so many digits in the exponent on the 10. However, please note that chess is a zero-sum game, i.e., if we rule out ties, in any game of chess, one player always wins and the other player always loses. Since chess is a zero-sum game with definite, unambiguous winners and losers, one of the fundamental theorems of game theory says that, for any zero-sum game, there is always an optimal (or min-max) strategy, i.e., a strategy that will maximize – not guarantee, but maximize – the chances that you will win the game.
Now, note that the rules of chess are quite simple. I could write down the rules of chess – which chess pieces can move where, and how they can move – on a single sheet of 8.5 x 11 typing paper. Strategies in chess is something else. Entire encyclopedias of volumes have been written over the years by grand masters of chess. But all those volumes on chess strategies, all the volumes that have ever been written or that ever will be written, all the strategies, all the gambits, are predicated on that one little 8.5 x 11 sheet of paper. Chess is anything but lawless, anything but random. But predicting how any given game of chess will play out, whether the players are novices or grand masters, is ultimately impossible, and even attempting to do so taxes the intelligence and memory of even the grandest of the grand masters.
Furthermore, understand that the so-called "min-max theorem" -- for every zero-sum game, there is an optimal strategy -- is only an existence theorem, i.e., it asserts that an optimal strategy exists, but gives no algorithm for determining what that strategy is. With some risibly simplistic games, formulating the optimal strategy is laughably simple. (Tic-tac-toe is also a zero-sum game. Exercise for reader: what is the optimal strategy for tic-tac-toe?) But as the complexity of a game increases, i.e., the number of moves, the number of entities (e.g., chess pieces) than can be moved, etc., etc., the difficulty of discovering the optimal strategy increases at a highly, highly, highly exponential rate. Network all the supercomputers that have ever been built, including quantum computers, and the resulting network would probably still not suffice to discover the optimal strategy for chess within the lifetime of the Universe. Furthermore, even if the optimal strategy were discovered sometime in, say, the 3525344362323332452445423rd century, understanding and writing down this strategy would be comparable in difficulty to discovering the strategy in the first place.
Yeah ... this is some real hard stuff! But the point is quite simple ... to wit ...
Despite being elegantly and pristinely rule-based, chess is inherently unpredictable. Or rather, it would be more strictly accurate to say that predictions about how a given game of chess will develop over time are reliable only provisionally – and that reliability becomes progressively less trustworthy as the game unfolds with time. It is like the weather: you can predict the weather a day or 2 in advance, but a week or 2 ... ? And a month or 2? Fug-gid-aboud-it! (Game theoreticians say that predictions about the progress of a chess match diverge as a function of time. Like weather forecasts.) Chess is chaotic. But chess is highly non-random. Chess is orderly but chaotic.
Same with evolution through natural selection. Once the random changes from cosmic radiation, asteroid strikes, volcanic eruptions, etc., have been factored in – and these are happening all the time – evolution remains, like chess, a chaotic process. But it is not random. It simply means that – again, like chess – everything that has happened and that is still happening gives rise to so stupendous a multitude of possibilities that prediction is a fool’s errand, certainly prediction in the long term. So is evolution also bound by rules, like chess? Unequivocally yes. In the case of evolution, the equivalent of my 8.5 x 11 sheet of paper is the entire suite of natural laws of physics and chemistry. These would probably not fit on an 8.5 x 11 sheet of paper, but they are immeasurably more compact than the great, majestic "tree of life" evolution, in adherence to these laws, has produced in around 4.5 billion years. Several years ago, I was reading the late Stephen Jay Gould’s remarkable book about the Burgess Shale deposits in Canada, and encountered a striking statement. I do not have the book at hand to quote verbatim, but Prof. Gould asserted that, if we were to rewind the process of evolution to the very beginning sometime in the Pre-Cambrian, then set the “tape” running again, it would not only be possible, but highly likely that re-running the “evolution tape” would result in an altogether different suite of organisms on earth, e.g., maybe an earth dominated by intelligent dinosaurs or by intelligent dolphins … or by no intelligent life at all. (The dinosaur and dolphin possibilities are my speculations, not those of Prof. Gould.) Appropriately enough, Prof. Gould entitled his book Wonderful Life.
That, in general, is the problem with conservative creationist / intelligent design ideologies: they are so desperate to fit the breathtaking sweep of the Universe and the development of life therein into the Procrustean bed of their narrow, religiously motivated categories that they end up impoverishing the very Creation they claim to admire.
James R. Cowles
Man looking through telescope ... Giuseppe Donatiello ... Creative Commons CC0 1.0 Universal Public Domain Dedication
DNA tree of life ... Pixabay ... Public domain
Evolution of a massive star ... JPL ... Public domain
Bird fossil ... Luidiger ... Creative Commons Attribution-Share Alike 3.0 Unported/span>
Richard Dawkins ... Mark Coggins ... Creative Commons Attribution 2.0 Generic
Chessboard ... Staxingold ... CC by SA 3.0