I’m having a light dinner while traveling off to a visit with Humanists of Minnesota, and I thought I’d deal with a little email. I got a request to address a fairly common creationist argument–here’s the relevant part of the claim.

As a member of the Greater Manchester Humanists I was recently involved in a discussion with the Ahmadi sect of Islam with regards to evolution. They had asked me to look at a couple of chapters in a book entitled ‘Revelation, Rationality, Knowledge and Truth by their prophet Mirza Tahir Ahmad. One of those chapters was called ‘The Blind Watchmaker who is also Deaf and Dumb’ – riffing badly on Dawkins’s book, of course. Suffice it to say, there was very little of any of that in the book, but during the discussion one of their number said he did not believe in neo-Darwinism because he could not see ‘how all the supporting and connecting mult-component systems could all have evolved as, for example, the eye, as it progressed through geological time.’ He quoted the hagfish and work done by Prof Trevor Lamb to show ‘just how complex those multi-component systems are’ – but when I looked up Lamb’s work it is quite obvious that he is a supporter of evolution, and that he in no way suggests that such complexity is divine in nature….!

Yep, he’s got us. If evolution were sequential, linear, and goal-directed, this would be a serious problem. If you’re used to imagining that the only way complexity can possibly emerge is by purposeful, serial action to build an end result, rather like putting together your furniture from Ikea or building a model airplane, then gosh, it all seems so impossible.

Unfortunately for the follower of Mirza Tahir Ahmad, none of that is true, and this is just a variant of the “it’s too complicated to evolve” argument, with more sciencey sounding words and references to misinterpreted fragments of the scientific literature.

Let’s consider the major misconceptions in the question.

Evolution isn’s sequential. It’s massively parallel. Massively. Humans have about 20,000 genes, and all of them are evolving at once, with trial runs in about 7 billion individuals. New variants are arising all the time, and then they’re tested to destruction in multiple combinations over time. Scrap your weird idea that the pieces of a complex system must be developed one at a time — they can’t, and all of them are being constantly tinkered with. It is the most badly designed scientific experiment or engineering program ever, with no controls and every variable getting randomly tweaked at random intervals. So don’t be surprised that multiple elements are getting juggled.

Evolution doesn’t care how it arrives at a solution — all that matters is the final effect on the organism. In the case of the eye, the viable end result is an organ with sufficient resolution and contrast, and various special purpose detectors for things like motion or looming. The organism doesn’t know or care how that comes about — it is born with a combination of attributes, and lives or dies by their success. It may have accomplished its end by, for instance, refining the lens, or fine-tuning the receptor, or building in secondary signal processing elements…or all of the above and more. The organism doesn’t care and doesn’t have any control. And in a massively parallel system, probably every level is being tinkered with, and the final solution is going to be multi-component . It would be weird if it wasn’t.

Evolution is not teleological. An organ like the eye is not being assembled to a set of specific, detailed instructions — it just has to work, or the organism is at a disadvantage to other organisms with better eyes. So a hodge-podge of solutions is accumulated, and the end result has all kinds of complexity. But you don’t get to argue after the fact that the details imply some specificity of purpose. For example, here’s a number: 343767. It’s kind of big, you might be tempted to argue that it’s a fancier or more complex number than, say, 300000 (you’d be wrong), or you might want to argue for the significance of individual digits, or find a pattern in it. Humans tend to do that. But the reality is that I just went to a random number service and asked for a 6 digit number. Similarly, eyes wandered through a random space constrained by functional requirements and ended up at a somewhat arbitrarily complex configuration — and different lineages followed different paths.