Thinking allowed

Life’s Solution

Life’s Solution is the title of a new book by Simon Conway Morris, Professor of Evolutionary Palaeobiology at Cambridge University. The subtitle Inevitable Humans in a Lonely Universe encapsulates what seems to be the book’s central thesis: that on an earthlike planet, the patterns of evolution are such that they will eventually bring intelligent life into being, but that there are precious few earthlike planets in the universe.

I plan to make further comments as I read the book; meanwhile you can buy it here — it looks well worth a read, though it’s a fairly demanding work.

So far I have read the introduction and Chapter One, so I hesitate to summarize the content of the book. However, Simon Conway Morris’s hypothesis seems to be that although there are potentially and enormous number of possible forms that proteins might in theory take, in practice the overwhelming majority of them are non-viable; that the experience of life on earth is that evolution will repeatedly invent similar solutions to the same problem, but using different building blocks. A classic example of this ‘convergent evolution’ is the similar eye that has evolved separately in octopuses and vertebrates. This suggests that there are ‘stable’ points in the world of evolving life-forms, and that given a favourable environment and enough time, they will be reached, perhaps repeatedly, but almost inevitably.

Taken with the stability of the physical universe, and the limited range that the basic physical constants may take to arrive at a habitable universe, it is tempting to see that such a universe is very compatible with the idea it was created in a way that would lead to intelligent life.

In his preface Conway Morris outlines the plan of his book, with chapters on the genetic code and DNA, on the difficulty of turning the molecules of life into life itself, the uniqueness of the Earth, then several chapters on convergence, and a final chapter teasingly entitled ‘Towards a theology of evolution’. He writes ‘if you are a “creation scientist” … may I politely suggest that you put this book back on the shelf. It will do you no good. Evolution is true, it happens, it is the way the world is … This does not mean that evolution does not have metaphysical implications.’

Chapter One discusses proteins, the building blocks of amino acids, the role of DNA in the manufacture of proteins, and the way that DNA codes the creation of proteins enzymes. The same DNA code is used by all life on earth, and so must date back to the very earliest phase of live on the planet. Yet it represents an extremely efficient coding scheme — a recent computer experiment to compare a million possible coding schemes chosen at random showed a normal distribution ‘bell’ curve; the actual code used in all creatures on earth lies far, far to the edge of this curve, way inside the last percentile, with only one of the million alternatives more efficient. ‘We may not only be on the verge of glimpsing a deeper structure to life,’ he writes, ‘but [also] that it matters little what our starting point may have been: the different routes will not prevent a convergence to a similar end.’

Enough extracts, time to get into some more reading, and perhaps some more opinions too.