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Creationism

On the first day

Creation 'science' is a painfully awful way of trying to reconcile the biblical account of the creation of the universe with the overwhelming physical and biological evidence contrary to such a literal interpretation of the bible.

The Eden story is just one of several thousand tribal creation stories (in this case, a pilfered Babylonian one), none of which have much grounding in reality. As such, it deserves no more than the cursory and respectful dismissal that we reserve for the idea that the universe was created from the ejaculate of Atum. Unfortunately, in several states of America, big bang cosmogonies and natural selection have been expunged from the school syllabus to be replaced with the grotesque pseudoscience of creationism.

I am not a physicist, so I will not delve deeply into areas where I don't know what I'm talking about - a common fault in creationist literature as we shall see. I am a biologist, so hopefully that bit will be accurate, but again, feel free to email me if you spot any stupid errors. Like calling rabbits ruminants, or similar.

What is evolution?

To save ourselves a few headaches, we ought to get our terminology cleared up. Evolution is the observation that species appear to change over time, and that they consequently appear to be related. There is huge evidence for these changes, such as the fossil record; the spread of antibiotic resistance in bacteria; changes in the genome of HIV over the last twenty years; extinction events; artificial selection in crops and domestic animals; and Darwin's infamous finches. Evolution can (although probably should not) be conveniently divided into microevolution (changes in the frequencies of genes in a gene-pool), and macroevolution (the splitting of gene-pools to form new species). In addition, we should distinguish evolution proper from abiogenesis. Evolution by natural selection occurs on variable, competing replicators (i.e. living things), and is on rock-solid theoretical and evidential ground. Abiogenesis is the theory that living things are descended from simpler 'abiotic' chemistry. The mechanisms by which non-life inched its way towards life are much less well understood, but hoping they will forever be inaccessible as a god-of-the-gaps 'argument' if ever I heard one.

Evolution is only a theory

The short retort is 'And?'. Calling evolution by natural selection 'only' a theory is both true, and so banal it barely warrants a response. Evolution itself (a change in gene frequencies) is a fact, i.e. something that has been observed to occur; it is natural selection that is the theory that is invoked to explain the data. It's only the theory of electrodynamics that accounts for the behaviour of your computer, but people seem happy enough basing world banking, life support machines and the internet on a 'theory'. Theory is a label we give to a coherent set of scientific ideas, not an insult; to use it as such shows a fundamental ignorance of scientific vocabulary.

So what are we left with then? A waterproof cupped leaf that can absorb nutrients. Leaves are generally waterproof, and all leaves can absorb nutrients by foliar feeding. Given that you can accept leaves as products of natural selection (and of course, the arguments can be carried on at any level), then all you have to worry about is how the leaf initially became cupped. I can drown insects quite accidentally in a deep plate full of water just by leaving it lying around for a day outside. The leaf equivalent of a deep plate are two-a-penny (saxifrages, nasturtiums, pineapples, giant waterlilies, lady's mantle, just off the top of my head). The Darwinian term for this is 'preadaptation': many structures built by natural selection did not start out as what they are now. Pitchers clearly used to be leaves, and ordinary leaves have certain ordinary leafy properties such as hairiness, stickiness and waxiness, that are useful for ordinary leafy jobs like waterproofing and shading from excessive sunlight. Some of these adaptations may accidentally also make the leaf good at trapping insects: and natural selection loves a preadaptation: bats' wings were originally hands, before that, feet, and before that, fins. Although ordinary hands aren't much use at flying, webbed fingers and arm muscles certainly are useful preadaptations for it. Interestingly, Roridula appears to be a carnivorous plant, but in fact, does not digest trapped 'prey': the glue seems to be there as a defensive, not an offensive measure. An insect-eating plant could readily evolve from a preadapted insect-killing one.

At every stage of the pitcher-plant's evolution, there is a gradient: deeper cups are better at drowning insects, more hairs are better at retaining strugglers, stickier leaves are better at snagging insect legs, and so on. There is no need for great leaps in any of the features, and there is certainly no need for all of them to be present at once for the trap to work at all. Pitcher plants can evolve by natural selection. Even if a given adaptionist 'just-so-story' turns out to be untrue, it's easy to construct eminently feasible and testable routes to adaptations.

The argument from personal incredulity is no argument at all: it's a whinge based on ignorance and lack of imagination.

Show me the missing links

The scientific answer to this old chestnut can look like a case of special pleading, but bear with me. The modern classification paradigm, cladistics, avoids the whole issue, by placing fossils on its 'family trees' (cladograms) as if they were still alive. Cladistics deals only with relationships, and not descent, because descent can never be inferred because of the vast scale of geological time. No-one can know for certain that a given species is my ancestor, because no-one was there keeping track of who mated with whom 400 million years ago: I bet you couldn't name your great-great-grandmother, let alone your great¹⁰⁰⁰-grand-organism. Ancestors certainly existed, but because we can never be sure that a given skull is on the direct line of descent to me, we don't assume it. However, as all organisms are related (the near universal nature of the genetic code attests to this), cladograms (like the one above) can justifiably show all relationships as cousinships rather than chains of descent. This is better science, because it leads to testable hypotheses, which theories based on descent cannot. There were ancestors, but it is better science to treat all fossils as cousins.

No organism ever lived its life as a stepping stone to something better: organisms exist, that is all. They have no goal in mind, and there was no half-fish-half-amphibian that made its living becoming the ancestor of all land animals. If such a creature existed (and something like it did) it made its living being a fully fledged organism, not a 'transitional form' on its way to something better. Who's to say that oak trees aren't the 'transitional form' that their intelligent descendents in a billion years' time will start imbuing with purpose, and talk about as if they were merely stepping stones in an imaginary chain of being that culminated in brainy-plants. Those who lay special emphasis on transitional forms are confusing being with becoming (see Henry Gee's book Deep Time).

Transitional forms clearly must and do exist; however, for most purposes, every species may be considered a transitional form, as all species are subject to evolution (regardless of scientific arguments about species spending time in stasis). We only lay special emphasis on changes that seem important to us in hindsight: the development of legs, wings, and other such trivia. The arbitrary division of vertebrate animals into fish, reptiles, etc., is just that: arbitrary, especially when you start including fossils. If we define a bird as a feathered creature, then what do we call things with proto-feathers, like many theropod dinosaurs? Particularly if these proto-feathers had nothing to do with flight? It is difficult to find fossils from the transitions that most obsess us: dinosaur-to-bird, fish-to-amphibian, and so on, but there is a very good reason for this. Speciation events probably occur quite quickly in rather small populations, usually geographically separated from their parent species. The fossil record is poor, and the chances of catching a scrappy outlying population of one species in the rapid process of becoming another are miniscule, especially if you are effectively looking in the wrong place (in the fossil bed of the large parental population). Furthermore, the large changes in form we are obsessed with may be associated with the exploitation of newly created habitats, and the adaptive radiation into the new niches probably occurs rather quickly too. Looking for fossils is a fraught business at the best of times; doubly so when looking for 'missing links' that clearly demonstrate a half-way house in some feature.

In one creationist pamphlet I read: 'There are no missing links: all hominid fossils are classified as either Australopithecus, in which case they are apes, or as Homo, in which case they are humans'. Avoiding the facetious comment that they writer of the pamphlet was too lazy to keep up with the discovery of side-branches to the hominid tree (Paranthropus), the reason for this is that every skull gets classified, and given that a classification is a way of squeezing continuously variable organisms into invariable strait-jackets called species, genera, and families, it is hardly surprising that there are no Australohomo fossils: if you can only count in integers, all decimals will end up rounded-up or rounded-down. It's worth noting from the cladogram above that Australopithecus africanus is in exactly this situation: it properly belongs in the clade Homo, but looks so ape-like it has been traditionally classified in Australopithecus. Even if such a clade as Australohomo were invented, its members would have to be either more closely related to Homo (…in which case they are humans…) or to Australopithecus (…in which case they are apes…), or be an outlier (apes). Using arbitrary classification schemes to argue pointless points is as silly as the argument over 'it's just a theory'. It betrays a fundamental ignorance of the subject matter.

The relatedness of living things is evidenced by the (near) universality of the genetic code (the 'dictionary' that translates the base-pairs (AGCT/U) of DNA/RNA to the amino acids of proteins); the common biochemistry of all living things; the mere ability to plot phylogenetic trees; and interesting observations of exactly which genes came from where, in for example, in photosynthesis.

Although 'missing-links' are badly named, difficult to find, defined arbitrarily and impossible to classify in any system based on descent, there is one thing that evolution does expect of the fossil record. This is that the earlist records of very complicated things should occur later in the fossil record than the earliest records of very simple things. This is exactly what is found: bacterium-like forms are found from 3000 mya, but multicellular organisms only from about 700 MYA. If anyone ever found a rabbit skeleton in the Precambrian, then I would forecast the end of Darwinism (as Huxley did). And faked dinosaur/human trackways don't count.

Microevolution occurs, but macroevolution is impossible

Some creationists deny the actuality of microevolution too, but they are a dwindling minority because even creationists don't like to use ineffectual antibiotics. Evolution is simply defined as a change in gene frequencies in a gene-pool over time, and there are only three ingredients that evolution by natural selection requires: a variable population of replicators (things that show heredity) that compete for limited resources. A varied population of replicators that compete for resources will evolve. If the variation is not open ended, then it may not evolve very for very long before shuffling into extinction, but that is a different issue. The only thing that the religious and sceptical amongst may wish to argue about is how many of the adaptations that living things have are due to natural selection on gene pools, and how many are due to species selection, spandrels, random drift, human intervention, god, gods, morphic resonance or pixie dust. You may not believe that the eye can have evolved purely by natural selection, however, a population of variable, competing replicators evolves. Period. To argue against that is to argue against a mathematical certainty, which is very foolish indeed.

This method is prone to some error, but there are various other radioactive clocks that can also be used, such as the uranium/lead clock. A favourite creationist argument is to point to a case where the K/Ar clock gives a widely different reading from the U/Pb clock. This is very typical of creationist evidence: despite the fact that the vast majority of clocks in the vast majority of rocks give reasonable agreement, a few rocks where one of the clocks seems horribly out of kilter are held up as a damning indictment of the technique. A scientist might be more likely to conclude that there is something funny about the rock than the technique: contamination, unusual geological circumstances, a broken mass-spectrometer, etc. Throwing the baby out with the scientific bath-water is a typical refuge of pseudoscientists, who never seem to use the same rigour to their own data: the idea that the majority of rock formations on Earth were formed by the Flood of Genesis is grotesquely and laughably at odds with the data.

The oldest rocks on Earth appear to date from around 4500 million years ago, which is plenty of time for a population of species to accumulate enough changes to be strait-jacketed into another. In fact, it's plenty enough time for this to happen many thousands of times.

A corollary of the second law is that entropy (disorder) increases with time. This applies only to the Universe as a whole (a 'closed' system): individual parts of the universe can become as ordered as they like, providing that this extra order is counterbalanced by the generation of (usually much) more disorder elsewhere. When water freezes, heat is dissipated into its surroundings (e.g. the refrigerant in the pipes at the back of the freezer), and this heat energy is a form of disorder. The expenditure of electricity in overcoming the friction of the pump of the freezer also produces heat, which further increases the disorder of the universe. Evolution does most certainly not contradict the second law: a human cell may be extremely ordered and highly complex, but it's paying energetically for that complexity every second it's alive. And so did all its ancestors. Every small increase in living order has been at a huge cost in disorder to the Universe as a whole. Again, complete ignorance of the subject matter is at the root of this foolish statement.

Evolution destroys information: only intelligence can create it

This is one of the ways to state the current creationist war-cry, that the universe requires 'intelligent design'. Of course, this is really just a tiresome recasting of the argument from design, but this time, the creationists think they have maths on their side.

Take an example recently rammed down my throat by a communicant, of the sentence 'the fox runs wild'. Two mutations to 'the foc runs wilx' apparently destroys information. Although the creationist in question didn't bother to explain to me how or why, let's see if it does. Shannon information, H, is defined as:

H = − ∑ p log₂ p

Where p is the probability of any given sentence. It is only really applicable to populations of sentences, so the creationist was already off to a bad start, since he didn't say anything about the population. If we have a population of ten sentences, all with the sequence 'The fox runs wild', the probability of finding this sentence is obviously 1, and the information we gain from its content is zero bits. If one of these sentences mutates to 'The foc runs wilx', the Shannon information increases to −0.9×log₂(0.9)−0.1×log₂(0.1) = 0.47 bits. Mutation in this case has generated information.

If you'd rather, we can consider each letter individually instead. However, to do this, we need to define the probability distribution of the letters, because Shannon's formula depends on p, the probability of a particular message (letter) in a population of possible messages (the alphabet). If you define all the letters a to z to be equally probable, then the information content of the two sentences is identical, because each letter carries exactly the same number of bits (about 4.6). If you do frequency analysis on this piece of nonsense to make the analysis more realistic, you find that each letter has an average information content of about 4.1 bits. Using the values of h calculated from this text, 'the fox runs wild' has an information content of 64.6 bits and 'the foc runs wilx' has an information content of 66.0 bits. Again, a higher information content than the original (other mutations will show decreases, like 'the fof runs wilu' with just 61.0 bits).

Basically, this is all irrelevant mathematical posturing. Creationists are trying to use a very specific concept from maths and physics - information - to argue a point about something quite different - the meaning of a sentence. It's the wrong tool for the job.

A better tool for the job is something like this definition of complexity. The maximum information content of a sentence depends on its length, but in a population of many sentences (a book), some possible sentences will be missing because mutation hasn't generated them, and others will be missing because selection has killed them off. The difference between the maximum and measured informations tells you how much information an English book encodes about the English language. This is intuitive: 'mi pensas ke kreatistoj ne scias pri kio li parolas' contains no information about English, and neither does 'askjdhasknbdasmndb', but 'the fox runs wild' does. Note that there's no need to fret about the meaning of the sentences: the information difference (using Shannon's simple definition) between an English book and a random text is simply taken to be its complexity.

This definition is also independent of what does selection, in case anyone thinks we need an intelligent agent to select out English sentences for the English book. You could instead look at a book written in iron-gall and note that an entirely unintelligent agent has selected and burnt out any sentences containing too many loops and ligatures.

To translate that into a biological setting, the difference between the information that the dolphin gene-pool actually contains, and the information it would contain if all possible gene-sequences were present (if mutation ran at ridiculous rates, selection was zero, and the population sufficiently large), gives a measure of the information that the dolphin gene-pool encodes about living in the sea and going 'prrrrp'; a dolphin being defined as the animals we find in the sea that go 'prrrrp'.

One thing to note is that an organism that is well adapted to a simple niche may well contain less information about that niche than an organism that is badly adapted to a complex niche. In evolution, we are really more interested in adaptation than simple information content: this is why the information theoretical guff of intelligent design is a red herring.

Life is too improbable to exist by chance alone: natural selection is a theory of chance

This 'argument' usually goes along the lines of:

"This protein is one hundred amino acids long. There are twenty amino acids. Therefore, the chances of this molecule arising spontaneously by random chance from a pool of amino acids are one in twenty times twenty times twenty…one hundred times. This is one chance in twenty to the power of one hundred. This is a bigger number than there are protons in the universe."

These huge numbers are down to not bothering to read up on what natural selection is about. Natural selection is the exact opposite of random chance. Mutation, which generates the variation in gene-pools that natural selection works upon, is random (with respect to adaptation), and occurs with sufficient frequency in a reasonably sized population to generate the raw material for evolution. However, although mutation is random, natural selection is completely non-random. This is the whole point of Darwinism! Poorly adapted organisms die, and better adapted organisms (those with a single amino-acid change that is useful) survive to produce more offspring. This means that in a few generations, every member of the population now carries the improved protein. That means that the huge improbability of one-hundred improvements occurring simultaneously to give us our protein is broken down into one hundred individual improbabilities. Because each improvement rapidly takes over the entire population, this means that these small probabilities are not multiplied together to give the over-all probability, because they do not have to occur simultaneously. They have to be combined in a more complex way, which still leads to a protein being an highly improbable and wonderful thing, but not an inconceivable one, given the time life has had to evolve. The huge numbers and tiny probabilities of creationist literature are the very thing that Darwinism explains, and criticising Darwinism as being a theory of 'chance' means that the criticiser hasn't the first clue what the theory of natural selection is about.

Your more thoughtful sort of creationist (a rare breed indeed) is likely to respond to this with an argument that natural selection can only lead to random fluctuation: after all, whether you need a warm furry coat depends on the random vagaries of weather. There is short-term fluctuation in some factors (particularly climate and weather) that affect evolution, so evolutionary changes in adaptations to climate tend to be short-lived and reversible; but there are other factors, such as the oxygen in the atmosphere - which increased steadily after the evolution of cyanobacterial photosynthesis - and particularly evolutionary arms races, where there is a continuous and steady pressure in a particular direction. Natural selection occurs at all these levels, causing change on all conceivable timescales longer than a generation.

Life only comes from life

The generation of living things (whatever that actually means) has never been observed to occur from non-living materials; Ergo, that means it never has. Notwithstanding that this simply (wholly discredited) vitalism in a slightly different raincoat, it is true that natural selection requires a starting point, some initial variation and heredity on which to work. Most scientists believe that simpler chemical processes led to the production of chemical systems complex enough to show heredity (replication) and metabolism (catalytic control over its environment), a theory which is termed abiogenesis. The evidence is currently vague and incomplete; however, the presence of amino acids in meteorites is not in doubt, nor is the fact that many of the precursors of life can be produced by electrical discharge through redox-neutral mixtures of gases; and RNA is known to be able to act as both a replicator and an catalyst. Abiogenesis is not water-tight, but 'life only comes from life' is merely an observation, not an eternal verity. Other messy bits of biological science, such as the evolution of multicellularity have been mightily cleaned up in recent years, and praying that no-one will ever produce a self-replicating metabolism in a test-tube is almost certainly a vain hope.

Darwinism is the root cause of immorality, Nazism and Communism

I've always found this rather an amusing statement, particularly coming from fundamentalist Christians. I was under the impression that the rise of Communism in Russia was due to a feudal monarchy abusing its power over a massive and oppressed workforce. Quite what Darwinism had to do with it, I don't know, particularly as the official Soviet line on evolution championed by Lysenko was that it was Lamarckian, a theory opposed to Darwinism. It's also somewhat amusing that so many American creationists are also dyed-in-the-wool libertarian capitalists, insisting that survival of the fittest in nature is incapable of 'designing' a highly imperfect organism; whilst believing that survival of the fittest in the marketplace will 'design' them a perfect society. The American God clearly believes in command-economics for ecology, but not for economics. Even more contradictorily, I was also led to believe that Yeshua bar Joseph was rather in favour of the redistribution of wealth and healthcare to the poor and needy. As for National Socialism, I was under the impression that its rise was due to Church-inspired rabid anti-Semitism, combined with hyperinflation during the Weimar republic. Eugenics, which I might add was not a policy pursued solely by the Nazis (sterilisation of the 'mentally deficient' was commonplace in Europe and America well before the second world war), is based on Darwinian principles, but just because natural selection is the way of the non-human world doesn't mean that it should be applied to the genetics of human society. The idea that morality would collapse without a strong fundamentalist Christian spine is laughable and tiresome.

Revelations

Creationism posits a complex creator god who is supposed to have designed all living things. However, a complex god is deserving of an explanation in its own right. A god that defies logic by being very simple yet capable of very complex things is a monstrosity. As Daniel Dennett says, if I tell you your god is a cheese and pickle sandwich, and you say 'well that's illogical and ridiculous', but then go onto tell me that he has the illogical attributes of being both complex and sublimely simple, then I can justifiably call you a hypocrite, and your philosophy flawed: either you use logic, in which case your god is too simple to do the job, or it is complex and deserving of a Darwinian explanation of its own; or you discard logic and reason, in which case you cannot argue against my statement that your god is a cheese and pickle sandwich. Creationism is a massive suspension of the logic, judgement and intelligence that the very same fundamentalists would like to think are god-given. It's a simultaneous slap in the face both to religion and to science, and should be laughed at by both.