As often as not when evolution is mentioned so too is randomness, be it the role of genetic mutation or a mass extinction triggered by a rogue bolide. Anything is possible, anything goes. It seems difficult to avoid the conclusion that evolution is little more than a freak show. And amongst this zoo of hopeful monsters what stranger exhibit could there be than human intelligence? Of all the possible examples of evolution can there be a more glorious accident? But is this correct? The study of evolutionary convergence (whereby the same biological solution repeatedly evolves from independent starting points) reveals a very different story, a world in which by no means all things are possible. In fact, evolution shows an eerie predictability, leading to the direct contradiction of the currently accepted wisdom that insists on evolution being governed by the contingencies of circumstance (most famously expressed in S J Gould’s metaphor of “re-running the tape of life”). Convergence encompasses the entire spectrum of biology, ranging from remarkable examples in molecular systems to the striking similarities found between social systems. In the former case the example of the enzyme carbonic anhydrase is highly instructive, because it has evolved independently at least five times. We can now say with some confidence that wherever there is carbon-based life not only must it “learn” to hydrate carbon dioxide but so too to do this it must “invent” carbonic anhydrase: it will be a universal molecule. And at the opposite end of the spectrum we have the literally colossal convergence between the societies of sperm whales and elephants. Convergence is ubiquitous, and involves not only enzymes and elephants, but things as surprising as the arms of the octopus, the running of vampire bats, and getting drunk. This lecture has been recorded on MP3: Simon Conway Morris FRS - Life’s Solution: The Predictability of Evolution across the Galaxy (and Beyond) This article was published on 2024-08-28
