Monday, March 13, 2006

ID, evolution and the appearance of design

Biological and biochemical systems look designed. Darwin accepted this. Dawkins accepts this. Richard Attenborough accepts this. I have little doubt that P.Z.Myers accepts this.

But darwinism allows us to believe that design is only apparent (“Paley was wrong”). Random mutation and natural selection provide a mechanism that allows things that look designed to appear without actually requiring intelligent design.

As evidence for this, a goodly number of examples are cited. For example: the presence of antifreeze glycoproteins in the blood of arctic fish; the ability of some bacteria to digest synthetic molecules; the adaptation of Darwin’s Finches on the Galapagos Islands to fluctuations in climate. Furthermore, there is some evidence for common descent. Organisms largely share the same genetic code; the same molecules are synthesised in similar ways throughout nature. There are even cases where you can observe loss of gene function in certain groups of animals – and why would this be present as a result of design?

From these examples and others like them, the conclusion is drawn that this naturalistic process is adequate to explain every living organism and every biochemical system.

Now, let’s look once again at the well-thumbed example of the bacterial flagellum. This sure looks designed – it has multiple components which work intricately together; it is incredibly well-adapted to its role; it is highly efficient. If we were to see something like this at human scale, we would have no doubt that it had been carefully designed and assembled; it wasn’t just a pile of bits that had been left over from other machines.

However, let’s remind ourselves that Darwin allows one to be an “intellectually fulfilled atheist”. So we can dismiss the fact that the bacterial flagellum looks designed – because we know that things that look designed aren’t actually designed at all.

But for a moment, let’s be awkward. Let’s say: “No. Although I accept that small-scale adaptations occur, I don’t accept that those examples of (micro)evolution reasonably permit the conclusion that a highly-adapted biochemical system could appear as a result of random mutation and natural selection.”

In scientific terms, this actually seems to be the majority opinion, according to various polls. Only a minority of people are prepared to accept what darwinists tell us – that random mutation and natural selection explain everything. If darwinists expect more people to accept their understanding of the nature of life, then they have to demonstrate that it really does have the explanatory power that they believe.

And darwinism has problems, in this regard. Darwin believed that evolution could occur as a consequence of an indefinitely large number of small changes – because he believed that at lower and lower levels, life would appear more and more simple. Dawkins largely followed him in this regard, with his argument that 10% of an eye was better than 9% of an eye. But this isn’t how evolution occurs. Rather than a series of small changes, a single lucky change seems to have caused the initial appearance of antifreeze glycoproteins in notothenioid fish, with small changes later on increasing their abundance and effectiveness. A lucky change seems to have occurred in the bacteria which can digest nylon. And where gradual small changes occur (in the finch population on Galapagos, for example), they don’t seem to have a lasting effect on the population.

So what about the bacterial flagellum? How might this have arisen? Nick Matzke has written what currently represents the most substantive paper on the subject of how the bacterial flagellum might appear. However, he acknowledges throughout his paper that evidence that might support his hypothesis is likely to be absent. There are occasions when he begs the question still further (if such a construction is allowed). For example, he says:
A diversity of export systems of varying complexity exist, and there is a functional continuum of membrane complexes ranging from single proteins and passive pores through to active, gated export systems, indicating that there are no major evolutionary puzzles to solve.
In other words (and yes, I know that this isn’t what he is getting at here, but it does seem to be the force of what he says):
if we assume:
(Premise)that export systems can evolve, and
(Premise)we notice that there are lots of different functional export systems in organisms, then
(Conclusion)we can conclude that export systems can easily evolve.
The logic is circular.

Matzke’s argument has been responded to more substantially by William Dembski.

So in actual fact, until it can be demonstrated that a system that looks designed (see below for a more careful explanation of the phrase “looks designed”) can appear as a consequence of random mutation and natural selection, it looks as though those people who believe in darwinism are actually begging the question. “The fact that things look designed doesn’t mean that they are designed,” they argue, then adding, sotto voce: “but I can’t definitely show you a system that looks designed that hasn’t been designed.”

Now there is a word that we use to describe it when people believe something that they don’t have evidence to be the case – and that word is “faith”. Darwinists have faith in darwinism.

Furthermore, it is misleading to argue that current objections to a darwinist explanation of life are just reworks of old creationist ideas. The fact is that the specific evidence that bolsters the case for design is generally no more than 30 years old. To argue that this is the same as the evidence for design that was being addressed by Paley and Darwin (and subsequently by Dawkins, in "The Blind Watchmaker") is to wilfully demonstrate scientific ignorance.

One particular irony is that certain people who have commented on my blog have then had the nerve to say that evidence that objects look designed is actually not evidence of design. The bacterial flagellum looks designed – as most people would acknowledge – but this isn’t evidence of design: it’s actually evidence against design, we are told, despite the fact that we have no evidence to support the opposing position, which is that non-design is able to explain the bacterial flagellum. By adopting this hard-line position, they are going further even than Dawkins, who at least acknowledged that entities and organisms look designed, and came up with a word (“designoid”) which acknowledged this fact.

Now, I don’t have a problem with the fact that ID isn’t something that can currently be demonstrated by science. I believe that it is fundamentally a worldview. I do have a problem with people arguing that a naturalistic perspective is more scientific. Certainly there are some things that this perspective explains adequately. But the design that is apparent in systems like the bacterial flagellum is not evidence that random mutation and natural selection are able to achieve what it is claimed that they do. It is only evidence of this if it can be plausibly demonstrated that they are a reasonable explanation of them - and this has not yet been done.

It may be the case that at some stage in the future an explanation which uses random mutation and natural selection will be able to show how the bacterial flagellum arose. This would seem to imply that ID is a “god of the gaps” argument. However, it is worth worth noting that is also possible that at some stage in the future, a cast-iron case could be made that the bacterial flagellum couldn’t possibly have arisen. The point is that you can’t dismiss an argument on the basis of evidence that may become apparent in the future. You just have to accept that all arguments are provisional until such additional evidence comes to light.

So to summarize, we have two positions.

1.Biochemical entities look designed because they are designed.
2.Biochemical entities look designed because random mutation and natural selection are able to produce complex biochemical entities.

To be clear, note that by “look designed” here, I mean not simply that they look cool, like a Porsche, or a snowflake, but that they include characteristics that in our experience are only characteristics of things that have been designed – that is, interacting components that are all required for the system to function, specification and so on.

As things stand, neither of these positions is “scientific” - neither is demonstrable from empirical observation; neither is derivable from the organised body of information. People with a bias towards option 2 would like to argue that the evolution of complex biochemical entities is a reasonable extrapolation from the fluctuating populations of Darwin’s Finches and the hypothesised evolution of antifreeze glycoproteins in notothenioid fish – but their case would look a lot more plausible if they could demonstrate the evolution of at least one complex biochemical system.