29 October 2009

The History Deniers

Sadly, there are those who deny the fact of evolution - 130 million of them in the US alone, according to a recent Gallup poll. These "history deniers" (an apt designation I'll borrow from Richard Dawkins) remain unconvinced by the veritable mountain of evidence for evolution, a mountain which grows day by day. Recent books, such as Jerry Coyne's Why Evolution is True or Richard Dawkins' The Greatest Show on Earth - though triumphs of reason and lucidity - will hardly make a dent in the legions of the history deniers, the "unsinkable rubber ducks" (to borrow James Randi's delightful phrase). It will take a greater concerted effort than just a couple of bestsellers to turn the tide, and it's up to us laypeople to do our bit, too.

Hence this edition of Pernicious Fallacies. In it, I shall be addressing dyed-in-the-wool creationists - the persuasion that believe that the Earth was created in 6 days less than 10,000 years ago, and that all modern species of animal, including humans, were created in their present form before God took His well-deserved day off. I shall not be addressing the more "sophisticated" proponents of ID (Intelligent Design), who actually believe in evolution, albeit a gimped kind of evolution, helped along at crucial junctures by a God who was apparently too lame to get it right in the first place. Whatever percentage of you are already down with Darwin, feel free to stop reading now.

From Wolf to Poodle

Yes, I'm bringing up the tired old dog breeding argument. I'm fully aware of the creationist counterargument, but bear with me, because I have a twist on it.

Selective breeding of animals with the intent to exaggerate desired traits over successive generations, or "artificial selection", is well known and well documented. Even history deniers comfortable with dismissing the fossil, molecular, and distributional evidence for natural selection would think twice before denying the comparatively recent historical evidence for artificial selection. A good example of what artificial selection can achieve in a short span of time is the modern banana. Though there are those who believe the banana was designed by the Almighty Himself, I'd like to think these people are embarrassments even to creationists.

At the core of it, all Darwin and modern Darwinists are claiming is that Nature, as well as Man, can act as a selective breeder, through the non-random survival (and more specifically, reproductive success) of individuals, and that this "natural selection" is responsible for all the diverse life we see around us.

Where creationists have trouble is with that last bit. The difference between breeds of dog, or cabbage, while oftentimes spectacular, pales in comparison to the difference between a dog and giraffe, a cabbage and a tree, or even a human and an ape. Thus they find it hard to imagine these tiny gradations ever leading to all the diversity of life we see around us, from the tiniest microbe to the blue whale. Evolutionists, when trying to help them see how this could in fact be the case, often say something like, "if you can turn a wolf into a poodle in a few centuries, imagine what great change could be wrought in a billion years!" A billion years. It's no wonder the evolutionists find it so easy to accept a single-celled organism giving rise to all life on Earth, no matter how complex it appears - look at the time they have to work with! But creationists, sadly, haven't the luxury. They don't have more than a hundred centuries to work with - and it's a bit confining, but it's what they're stuck with.

Thus creationists accept (as they must) that artificial selection works, but only up to a point. "You can create variations of dogs and cabbages with the process," they'll concede, "but you'll never make a new species. Only God can do that." There's always the matter of the definition of "species", which began as scientific terminology and should remain thus, and should not be used to mean "groups of animals so obviously different I can tell them apart". But let's leave that to the side, as it really doesn't matter for our purposes here.

Creationist's Evolution

So let's, just for the sake of argument, concede the point. The Earth is only 10,000 years old (you could concievably buy that many candles for its birthday, whereas 4.6 billion would really put you out, so that's something at least), and you can't make a new species using evolution. So as a creationist, you accept artificial selection, and with a few logical leaps accept (let's say) natural selection as a comparable agency with comparable effects. It would then follow that all modern animals are at least as different from their ancestors in the days of Genesis as modern dogs are from the archetypal wolf. Or would it necessarily follow? To be sure, there are still wolves - certainly not the same wolves from the dawn of time (none live that long, of course), but a branch of descendants that differ very little from the archetypal wolf (God's wolf, if you like). So, would it follow then that at least most modern animals are as different from their original forms as a poodle is from a wolf, while some percentage have somehow managed to remain unchanged (conveniently for us, as we could use them as near examples of what the "Adam and Eve" of that animal species might have been like)?

This "creationist's evolution" I have led you to is not what I believe, of course, but it is reasonable within the framework of creationism. It would even help answer some prickly questions about God and creationism. For one, God would only have to have made a template for each animal species, an animal "Adam and Eve" as I put it. This template of His would then be subject to explosive variation at the hands of either Nature, or meddlesome Man, it matters little which. This would shed some light on God's apparent pre-occupation with beetles. Furthermore, it would make Noah's job a heck of a lot easier. A couple of spiders on the Ark might be bearable, but two of each of the 40,000 spider species?

I have made these points in an attempt to outline a kind of evolution in which a creationist might be comfortable believing. I wanted to make "evolution" less of a dirty word - it just means change over time, people. Unlike "atheist" or even "humanist" it doesn't have an inbuilt denial of God, or even of a Young Earth. It might be unpalatable to true Darwinists like me, but it could be useful for opening a dialogue, finding some common ground. After all, a denial of "change over time" is harder for a creationist to muster, especially with domesticated animals staring them in the face. This merry chase of "creationist evolution" is meant to divest the mere word "evolution" from the uncomfortable, monkey-laden specifics of Darwin's theory that creationists so revile.

But is even this Godly evolution inoffensive to the creationist? Or is even this ecumenical fiction I have constructed - no worse than most theological musings - still going to ruffle some staunch feathers? It might at that, because of something called "Platonic Essentialism".

Master Tapes, Signal Noise, and Wikipedia

It was argued by Plato that, for everything that exists, there is an ideal example (perhaps existent somewhere, perhaps not), an "essence". Every triangle, it might be said, is but an imperfect approximation of the "perfect triangle", drawn by fallible human hands on stone, papyrus, or today made of tiny pixels on a screen. In the same way, might there be an "essence" of every animal species, and every member of the species is but an imperfect approximation, cast from the essential mould? In the terms of our "creationist's evolution", these "essences" would be the animal Adams and Eves, the original ancestral archetypes of all future animals. Every animal born in the species would, instead of copying their own parents, copy instead the archetype, cast by God and therefore perfect.

We can here use the analogy of "master tapes". When (back in the day of VHS and audio cassette) a company produced thousands of tapes for the public to buy, each tape was a copy of a master tape (or, I imagine more rarely, a set of master tapes). It wouldn't have been wise to copy a second copy of the master tape, and then make a third copy by copying the second copy, and so on down the line. By the time you reached the thousandth copy, the picture (or sound) would have deteriorated far too much to be useful.

I must digress here briefly for the benefit of evolutionists. This "copied tape" argument is sometimes leveled against evolution as evidence against it. A thousandth generation VHS is mush - so how can a thousandth generation rabbit be anything but mush, if evolution is true? The answer is that VHS technology is analog, and the signal noise introduced with every generation is faithfully reproduced in the next. But DNA, the replicator upon which life depends, is digital, and signal noise doesn't accumulate quickly enough to reduce the message to mush. Certainly errors occur, as they do with our manmade digital devices, but they occur much more seldomly. At this diminished rate (characteristic of a digital process) the errors - mutations - don't build up, at least not in the same way. What do I mean by this?

Think of it like Wikipedia. Imagine any Wikipedia article of your choice as a gene pool, and any edits that are made to it as mutations. Anytime a deleterious edit is made (vandalism, misinformation, etc), it is promptly removed, reverting the article to its pure state. In the same way, if an individual bears a mutant offspring whose mutation has a harmful effect on the offspring's survival or reproductive success, that mutation is in effect removed from the gene pool. Unlike the signal noise on a VHS, the mutation will never reach a successive generation because it isn't as good at getting there. If a Wikipedia edit is constructive, however, it will not be promptly removed. Instead, it will persist. In the same way, any mutation, no matter how rare, if it has a positive effect, will persist. (We can ignore the specifics of neutral mutations, which - while well understood - complicate the analogy.) Even if in any given generation the vast majority of mutations do not have any positive effect, over time, the only effects that remain will be the positive (or neutral) ones. Negative, harmful edits (or mutations) simply cannot persist for long at all.

Thus, in a digital process such as this, signal noise does accumulate, as in an analog process. The difference, however, is that instead of descending into formless mush, the "noise" that accumulates hardly deserves to be called "noise" at all. Mostly, they are improvements. Of course, this can only work if there is some outside force acting on the system. In the case of Wikipedia, it is a vast public, who only find constructive edits to be useful. In the case of DNA, it is the reproductive success of the bodies it builds. In any situation where there is no outside force, the "noise" really is noise, and not improvements at all, no matter how digital the process. One such example would be hereditary diseases in humans (and of course all animals). They all, without exception* (save those rare few that have newly mutated this generation, which cannot in good conscience be considered hereditary at all) present after the afflicted individual reaches reproductive age. Why is it that we are at such greater risk of so many health problems when we reach old age? Simply because we have already reproduced by then. Natural selection, like a finicky Wikipedia moderator, has swept up all the spills that kill us early. But those beyond its reach hang doggedly on, causing much misery.

* Actually, there can be some exceptions. For instance Haemophilia can be carried into future generations through the female line, only causing harm when it arrives in male bodies. But my general point - that a fatal gene that switches on at age 7 will be swept away by natural selection, whereas one that switches on at age 70 has a much higher chance of becoming frequent in the gene pool - stands.

So, now back to the "master tapes" and the archetypal animals. The Essentialist viewpoint would be that every mutation is necessarily deleterious, and that none should ever persist. Any deviation from "God's rabbit" would be an imperfect rabbit, and God would presumably not want his divine rabbity plan to be eventually lost in signal noise, even digital, naturally selected "noise" that resulted in a fully functioning animal thousands of years hence. It might be a great animal, fantastic at survival (it couldn't be around if it wasn't), but it wouldn't be rabbity enough for Him.

But we know from incontrovertible evidence, from centuries of artificial selection, oftentimes performed as direct experimentation, that animals don't copy some ideal "essence". They (and we, for we are animals) copy our parents. Anybody denying evolution, not just Darwinian evolution with all the trappings, but evolution of any kind, even the "what happens within a species stays within a species" kind of variation I suggested earlier, has to be able to show (or at least formulate some sort of reasonable argument for) why it has not happened. After all, if we can change a species by our own hand using artificial selection, how can we expect natural selection to have done absolutely nothing, even in 10,000 years?

Natural Selection - Friend or Foe?

Perhaps natural selection is not a creationist's enemy, but their friend. Perhaps natural selection can be invoked to explain how animals (and humans) remain the same today as they ever were (if we grant the creationists this viewpoint temporarily for the sake of argument), even in the face of all the mutation that must occur.

In fact, one of Darwin's contemporaries, Edward Blyth, suggested just such a thing. He suggested that natural selection, far from guiding the cumulative mutations toward evolutionary ends, instead strictly penalised any variation at all. So natural selection didn't work to improve, but merely to maintain the status quo.

I find it ironic - given that evolution (in the sense of "change over time") is undeniable, and practically a tautology - that the onus is on creationists to explain how in their view it in fact did not happen to any animal at all, until meddlesome humans began their breeding experiments. And that perhaps the only way to do so is to embrace the theory of natural selection itself, as a kind of universal janitor, mopping up any rabbits that aren't quite up to spec.

As it happens, though, this view of natural selection turns out to be false, and isn't worth clinging to. Why? Because of the Second Law of Thermodynamics, which basically states that, in any closed system, entropy will always increase. Creationists should be familiar with the Second Law, since many of them love to claim that Darwin's theory violates it.

The Second Law

Of course, they are infantile to even suggest it. They should pause a moment before leveling such an accusation at evolutionists. Think what you are accusing us of! There is a famous quote by Arthur Eddington:

If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.
By this, Eddington is stressing just how important the Second Law is to scientists. Do creationists really believe that the entire scientific community believes in a theory that violates such a fundamental principle? Ask any scientist if a perpetual motion machine is possible, and they will tell you "No" without any hesitation. There is no way that evolution even comes close to violating the Second Law. How can we be sure? Because every reputable scientist alive supports it. It's iron clad. It would have been rejected with due scorn otherwise, and evolutionists would today be loonies in their garages with deely-bobber hats investigating crop circles and drawing pentagrams.

Blyth's theory, however, would violate it. Short of God's continual intervention, no force can stop the accumulation of mutations in DNA. Bad mutations die, good mutations survive. Eventually, the gene pool is full of nothing but the creme de la creme, a book of happy accidents. By chance, some mutations, no matter how few, are going to be better at surviving. Nothing will stop them from taking over. There is no grand industrial machinery checking rabbits against some ideal template. If DNA can change for the better, to take better advantage of its environment, it's going to. Like a ball rolling down hill, it has to happen. The energy and information necessary to keep everything adhering to some essence, eternally immutable like the Heavens of the ancients - where does it come from? The energy necessary for Darwinian evolution comes from the sun - the math can be done, nothing else is needed. But to be truly unchangeable - to not evolve - that would violate the Second Law.

So, is that what God does? Does he sit up there all day, making sure that everything matches His divine specifications? Even the theists can but guess.

I hope I've shown, in some small way, that evolution, whether complete with all the Neo-Darwinian trappings that I believe in or not, is ineluctable. The history deniers must answer to their own satisfaction how it can not be. You have built your own Ark, and you must deal with the consequences. This is evolution's foot in your door - can you really ignore it, no matter how dilute the form, any longer?

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