The Cambridge Alumni magazine this month has an interview with Professor Simon Conway Morris hos is proposing what the articles describes as a “radical rewriting” of evolution. His theory is that convergence - “the tendency of very different organisms to evolve similar solutions to biological problems” - is not just a side issue but the “driving force” of evolution.

Conway Morris says, “If you go to the octopus, and if you’re not too squeamish, dissect it, you’ll find that it has a camera eye which is remarkable similar to our own. And yet we know that the octopus belongs to an invertebrate group called cephalopod mulluses, evolutionarily very distant indeed from the chordates to which we belong. The common ancient ancestor of mulluses and chordates could not possibly have possessed a camera eye, so quite clearly they have evolved independently. The solution has been arrived at by completely different routes.”

Evolutionary biologists recognize convergence but the issue, Conway Morris says, is “whether it means anything.” He elaborates, “when thinking about the combinatorial possibilities, the numbers of things [biological solutions] that ought to work is ridiculously large, whereas we seem to find that the number of things that actually work is surprisingly small - a very small fraction of all possibilities.” Evolution is not random, but converges on the best solutions. He suggests that “the manner in which life constructs itself must be dealing with some other principle which we’ve failed to identify.” Not “vitalism” and not something “deeply mysterious,” mind you.