Yesterday, I went to an interesting talk by Simon Conway Morris (Professor of Evolutionary Paleobiology at Cambridge) – it was one of those great lectures that starts off from a simple premise, in this case convergent evolution, and then takes that idea on a wonderful journey that touches upon the inevitability of intelligence, culture, social systems and the Fermi Paradox.
What he was saying wasn’t completely new to me – that there’s a phase space of ‘possibilities’, whether they be biological, social or cultural, and that some points within that space are more stable than others – has been said before. However, Morris was much more convinced about the idea that if we were to ‘rerun evolution’, things would not necessarily turn out to be as different from what we have today as you might expect. In other words, chance events (e.g. the first hominid falling off a tree and breaking its neck, or the K/T impactor) are vanishingly small influences on evolution when compared to the relative sparseness of stable configurations of molecules/individuals/bone structures, etc.
One interesting example which I intend to look into when I have more time (i.e. probably never) is the assertion that the structure of DNA is so good that it is not simply ‘a bit better than everything else’ – it is that all the alternatives are so crashingly rubbish that DNA is one of the only ways in which to create a decent molecule capable of carrying large amounts of genetic information reliably, given the starting materials of amino acids and suchlike.
So, it’s not that Morris believes that there is some kind of directionality to evolution, but he does believe that there are only a few good ways to do certain things. Another good example is the social organisation of beehives.
As far as we can tell, the whole ‘hive’ structure has evolved independantly a few times, indicating that it is a pretty good structure. However, apparently the fossil records indicates that in the past, bees and insects used a whole panoply of social organisations completely different from hives, but of course none are around any more, so hives are not just slightly better than the rest, they are much better. Morris then mused about how this might be due to the aggressive pursuit of resources and their efficient distribution, and what this implies about other ‘successful’ societies…
So it turns out that Matt Webb is talking about the same thing today; he is taking issue with New Scientist’s treatment of essentially what I’ve mentioned above – that there may be some constraints (this is a bit of a strong word, but anyway), biochemical or otherwise, that could ‘guide’ evolution (guide is not the best word either). Now, I’m the first person to get irritated with New Scientist’s sensationalisation of science, and I too am a bit bothered about how the scientists seem to be tracing out an inevitable path of evolution (selective quoting may be the culprit here). I suspect that they only said that to try and make things easier for the the public. In any case, the central thesis remains the same.
Matt is not happy with the idea that evolution is somehow deciding where to go next – but I don’t think anyone is claiming this. What’s being claimed is that there are only a few good ways to do certain things (like see, or move), and yes, you’ll end up trying all of them through random mutations, yes, and you’ll choose the good ones through natural selection. But important thing is that if you were to repeat the process again, because there are only a few good ways to do a certain thing, you’ll end up with organisms taking those very same routes again. That’s the new idea. And I don’t think that Matt’s ubiquitous ‘push’ and ‘pull’ dichotomy does not sufficiently describe this subtlety well enough.