Of all science-related controversies, the old evolution/creation argument seems to be the hardest to lay to rest. Lately, it’s been back in the news following attempts in several US states to introduce the teaching of creation-related content in science lessons and its appearance in science lessons at the UK’s Emmanuel City Technology College in Gateshead 1 (sponsored by the allegedly evangelically-motivated Vardy Foundation). Add to the mix the refusal of George Bush and Tony Blair to condemn this outright, renewed calls from the religiously motivated to at least “teach the controversy” and the arrival of “Intelligent Design” on the scene. Stir well.

This conflict has a long history. It goes back to the early days of Charles Darwin’s theory, when the publication of On the Origin of Species led to a furious public controversy culminating in the famous debate between Darwin supporter Thomas Henry Huxley and Samuel Wilberforce, Bishop of Oxford, during the 1860 meeting of the British Association for the Advancement of Science, 2 bubbling to the surface again with the 1925 Scopes “Monkey Trial”, when teacher John Scopes was tried for violating Tennessee’s anti-evolution law by teaching the theory in school. 3 In the 1980s, there was a concerted effort – largely driven by an organisation called the Creation Research Society (CRS) – to get “creation science” taught in US schools. The CRS is an extreme evangelical organisation founded in 1963 to assert the absolute scientific truth of the Bible; its formation was largely a result of the difficulty experienced by members in getting their papers accepted by mainstream scientific journals.4 This led to the Arkansas “Balanced Treatment Act” and the Louisiana “Creationism Act”, making the teaching of Creation as (at least) a theory on a par with evolution mandatory in their schools. The US Supreme Court, however, thwarted these attempts in 1987, when, considering the Louisiana Act, it concluded that “the primary purpose of the Creationism Act is to advance a particular religious belief”, and that because “the Act endorses religion in violation of the First Amendment” 5 it should be struck off. As a result, attempts to cast doubt on the veracity of evolutionary theory adopted a lower profile for some years, until the advent of a new approach in the 1990s – Intelligent Design (ID). 6

The thin end of the wedge

Where Creation Science was, in essence, about asserting a religious view of the origins of life and then finding the scientific data to back it up, Intelligent Design purports to take the opposite tack. The ID hypothesis proposes that if you look at the life sciences you will see pieces of evidence that cannot be explained by evolutionary theory and so require another explanation – these usually being processes and structures that are, it is said, too complex to have come about by the gradual alteration of form that Darwin (left) put forward as the basis for evolution. In other words, only the complete form makes sense – any partial version would be useless to the organism, and so evolution would select against it.

The alternative, ID advocates suggest, is that these structures show the hand of a designer who has directly intervened to shape these elements. They do not, however, draw any obvious conclusion as to who this designer might be, although in most presentations of ID the conclusions leave an unmistakably deity-shaped gap. Indeed, William Dembski, a mathematician and vocal ID supporter, describes ID as a scientific programme that leads to an understanding of a generic supernatural intelligence. None the less, while Creationism tried to assert that evolution was innately antithetical to religious belief,7 ID makes no such assertion – it merely suggests that evolution is scientifically flawed and that ID is a better way of making sense of the available scientific evidence. This has had the effect of giving ID a far broader appeal than Creationism; it leaves room for any religious explanation, not just the Christian biblical account, as well as for non-religious ones. There is, for example, nothing in ID that is incompatible with the Ancient Astronaut hypothesis of Von Däniken et al. At the 2004 UnConvention, Loyd Pye spent almost half his presentation on the Starchild Skull making this very point.8

In fact, the idea that ID is religion-neutral seems to be somewhat disingenuous if one considers the stated aims of the Discovery Institute,9 the Christian think tank to which William Dembski is affiliated and which has been behind the ID push in recent years. In an internal fund-raising document known as The Wedge Strategy and written in 1999, it decries the “devastating cultural consequences of scientific materialism and its destructive moral, cultural and political legacies” and outline a 20-year strategy that aims “to replace materialistic explanations with the theistic understanding that nature and human beings are created by God”. The Discovery Institute was not best pleased when this was leaked online after being accidentally left in a copy centre.10 To achieve their aims, DI members attempt to portray evolution as “a theory in crisis”, and to encourage educational institutions to “teach the controversy” – both of which come as a surprise to evolutionary scientists. To them, evolutionary theory seems to be doing just fine, and any real controversy was conclusively laid to rest shortly after Darwin published. The “theory in crisis” idea attempts to portray evolution as just one possible hypothesis that has been given unfair prominence, while the idea of “teaching the controversy” is intended to be the thin end of the wedge, intended to create a situation in which people who wouldn’t necessarily support ID itself might at least mention it in the name of “fairness” and “balance”, even though there is no genuine scientific controversy to answer.

Understanding evolution

Before we consider the claims of ID, it is useful to briefly recap on the basics of how the Darwinian theory of evolution works. One of the points raised about the theory of evolution is that it is “just a theory”, so perhaps it’s worth looking at what we mean when we use the word “theory” itself.

In common usage, a theory usually means a guess or speculative idea, but in science it does not; it is something far more specific. In science, a theory is a logically self-consistent model or framework for describing the behaviour of a certain natural or social phenomenon, either originating from, or supported by, experimental evidence. In this sense, a theory is a systematic and formalised expression of all previous observations made that is predictive, logical, testable, and has never been falsified despite repeated attempts. And it is in this sense that evolution is a theory.11

Evolution itself, in essence, is very simple. There are three components to the process: variation, death and time.

The form of an organism is an expression of the genes it inherits from its parents, which in turn came from its parents, and so on, back through time. But as the genes from two parents combine to form one individual, and mistakes take place in the genetic processes, variation is introduced into the system. None of us, for instance, look identical to one other – genetic variation ensures this, and it goes beyond appearances. Among humans or other species, there will be all sorts of minor variations, in metabolic function and so on, and these are essentially random.

All organisms need to survive in the environment in which they live. If they have a variation that means they are more susceptible to disease, can’t secure food effectively, or can’t escape predators, they tend to die before they reproduce. This natural selection is not random, but an intense pressure put on organisms by the environment; you could perhaps envisage it as a fine-meshed sieve, through which only the best-suited pass and survive, and when a variation enhances this process, it soon spreads as its holders get to breed more.

Most organisms exist in populations of millions of individuals, and these populations persist over millions of years, giving immense opportunities for this kind of change to act on them; in addition, all sorts of other variations are acting together at the same time. It is this that leads eventually to the generation of new species. This last part is the hardest to grasp. Humans are not good at understanding huge numbers and long timescales; these aren’t the dimensions we’re used to working with. But if such gradual processes, taking place over vast expanses of time, are somehow counterintuitive and hard to grasp, it doesn’t mean they are not real. In fact, in certain cases, we can observe them happening on a more human timescale. We can see concrete examples in the rapid evolution of drug resistance in bacteria, in the size of cod in the Atlantic fishery, in horns on hunted bighorn rams, in the mating strategies of side-blotched lizards and in many other places, including the Galapagos finches studied by Darwin himself.12

Of course, it sounds a lot simpler put like this than in actual practice, where the interplay between environment and genetics makes things far more complex. And, of course, the behaviour of genes themselves – unknown to Darwin and proposed as the basis for evolution only after his death – makes evolution a more sophisticated process than Darwin could ever have imagined. It’s not only what genes are that has an effect, but also how many there are, where they are, and when and in what order they are activated. While Darwin was firmly for evolution through gradual change, rapid change is now also known to happen, and the effect on organisms of even minor genetic changes can be surprisingly great.

In addition, people often find it hard to grasp that evolution is not teleological – that it has no direction or intention and is not trying to get anywhere. There is no drive to produce “higher”, more complex or more developed organisms – evolution simply responds to the selection pressures of the environment around it, resulting in organisms able to survive in the prevailing conditions.

Relatively few ID proponents are practising biologists with a mainstream science background, so perhaps it isn’t surprising that they miss a lot of the detail and thus find evolution unconvincing, even if we discount their religious agenda.13 Over the century and a half since On the Origin of Species, evolutionary theory has proved a powerful means of accounting for life as we know it; it has generated huge numbers of testable predictions14 and informs a massive swathe of successful biology and medicine. It is not nearly as fragile as ID supporters might like.

Stacking the odds

So, if ID is supposed to be a scientifically based alternative to Darwinian evolution, how strong is its case? In fact, ID is able to accommodate evolution to a degree – it has no problem with all organisms having a common ancestor or with evolution having led to many of the features of today’s organisms, but it also believes that some parts of life “did not happen randomly, but through purposeful design”.15

The argument for this is based on selecting biological systems that appear too complex to function successfully except in their complete form, and so could not have evolved gradually. This is actually not that different from a key claim of Creation science, which also relies on irreducibly complex systems as a main plank of its argument. But ID uses different examples for its evidence and allows evolution a slightly greater role. It essentially proposes an interventionist entity that allows evolution to take its basic course but periodically adds an irreducibly complex designed element to make things work better. For Creationists, the eye was a vital piece of evidence as it seemed to be something that either worked as a whole, or not at all. Much capital was made of this until evolutionary fundamentalist Richard Dawkins demonstrated a sequence of light-detecting features in living organisms that ranged in steps from a light-sensitive skin patch to the full human eye; since there are plenty of workable semi-eye options in the present day, there was no reason the same could not be true of evolutionary history.

Initially, ID proponents made much of bacterial flagellæ, little spinning tails some bacteria use to propel themselves, arguing that these only work with the full set of 40 proteins that make up the system. This example is falling out of favour now that the common stomach bacteria Helicobacter pylori has been shown to do it with just 33 proteins and precursor systems to the flagellæ have been found that have some of the components, but do a different job. Instead, the protein complexes used in blood clotting are now being claimed as “irreducibly complex”, needing 10 proteins all working together to do the job, the system failing if just one is absent. However, jawless fishes do it with just six proteins. The fact that a certain amount of evolution is allowed works in ID’s favour here. When a system is shown not to be irreducibly complex after all, it can quite happily be assigned to being part of the evolved element of the organism, and another example selected, rather than the whole hypothesis being exploded; a process that can be continued almost infinitely without ever disproving ID’s claims.

Mathematical arguments are also marshalled to support ID, particularly by William Dembski,16 who has claimed that the odds against complex structures arising from chance mutations are impossibly vast. He has carried out studies in which he looks, for example, at the chance probability of two proteins being able to fit together to perform a particular biological function. In each case, he has found the odds are so long that they rule out any explanation that doesn’t involve deliberate intent. This looks superficially convincing. However, Dembski falls into the teleology trap – his calculation attempts to ascertain the likelihood of getting this combination of proteins by chance if that combination was the goal being aimed for. As we know, evolution simply goes for a functional outcome, not a specific one; if you look at the proteins in different species they can vary by up to 90 per cent in their structure and still perform the same function.

In terms of statistics, an argument like Dembski’s is known as the retrospective fallacy. It was summed up neatly by cell biologist Kenneth Miller, who described it as like equating the odds of drawing any two pairs in poker with the odds of drawing a particular two-pair hand – say, a pair of red queens, a pair of black 10s and the ace of clubs. “By demanding a particular outcome, as opposed to a functional outcome, you stack the odds,” Miller says. And if you look for the odds on getting a functional outcome, they fall back into the far less impressive range where chance could easily account for the result.

A variation of this is what is known as the ‘Goldilocks Effect’. It has been observed that the physical laws of the Universe seem to be exactly tuned to allow the existence of humans, and for ID proponents this points to a designer being responsible. But this too is a retrospective fallacy – if the laws were not right for us to exist, we would not be here to comment on them, though maybe something else would. Stronger evidence for a designer would be the presence of humans if the laws of the Universe seemed to rule our existence out.

Perhaps most damaging for ID’s claim to be a scientific alternative to Darwinian evolution is the fact that it doesn’t make testable predictions; its vagueness about how the designer operates makes this impossible, as does its failure to set an unambiguous benchmark for what constitutes design and what doesn’t. It’s perhaps not surprising, then, that there is very little practical research into ID taking place, with its followers acting more like a pressure group than a body of scientists. The evidence ID puts forward is just a critique of Darwinian theory, not the basis of an alternative theory; it relies on spotting alleged gaps in science and then claiming a designer is needed to fill them, which both misunderstands the scientific process and resurrects the theologically discredited ‘God of the Gaps’, in which the realm of God is seen as the ever-shrinking domain outside of scientific knowledge.

Culture wars

So, where does this leave ID in relation to evolution? While science is able to make testable predictions that can lead to strong explanations of the world as we see it, ID cannot; it cannot, therefore, be considered a scientific hypothesis.

Well, actually, this isn’t quite true. In fact, ID does make one testable prediction: that there is a designer. If ID proponents can actually come up with the designer(s) in person, then their case would be proven, although I would place this at the more unlikely end of the spectrum of possibilities.

But then, it’s not actually about science, is it?

William Dembski admits as much in his 2004 book The Design Revolution: “To require of ID that it predict specific novel instances of design in nature is to put design in the same boat as natural laws, locating their explanatory power in an extrapolation from past experience”,17 and it is clear from The Wedge Strategy and other documents from fundamentalist evangelism that this is just an opening salvo in an assault on culture, the aim of which is not to deal with errors in science but to destroy the dominant culture of secular humanism.

The Fundamentalists view science as essentially atheistic and the cornerstone of secular humanism. They believe that the best way to overthrow this worldview and replace it with their own is to attack science, and they view evolutionary theory as both the epitome of science’s secularity and its Achilles heel. It doesn’t really matter to them whether or not they are right about ID, Creationism or any other theory, so long as they put it over forcefully enough to sow seeds of doubt about science in the minds of the non-scientific public.18 ID is merely another strand in the attempt to force a theocratic hegemony on the United States – an attempt that elsewhere sees climate change being ignored, abortion re-criminalised and foreign policy being based on chats with God.