The Game is Over

John Maynard Smith has died.

While many people know who Stephen Jay Gould was or Richard Dawkins is, Id bet few would be able to identify Maynard Smith. Thats a shame, because he played a key role in building the foundations of modern evolutionary biology. (Underlining this point, I only learned about his death from Science's online new service. As far as I can tell, no one else has run an obituary.)

Maynard Smith came to evolution from a previous career as an engineer. In World War II he measured the stress on airplane wings. When he moved to evolution, he brought with him a gift to see the mathematical underpinnings of things, whether they are bridges or botflies. (An awful lot of creationists are engineers, for some reason; they would do well to consider Maynard Smiths example.)

Maynard Smith saw evolution as a very complex mathematical equation that played out over time. Genes spread or faded depending on their fitness, which depended in turn on changes in the environment. Maynard Smith came up with brilliant new formulas to describe that change, in some cases borrowing methods from other disciplines. For example, economists have delved deep into game theory over the years, working out the ways in which players with different strategies can wind up winning or losing. Maynard Smith had the brilliant idea of apply game theory to evolution. The players in his game might be a population of elephant seals, each with its own genetically determined strategies for finding a mate. Different strategies would have different levels of success. One strategy might be to confront the biggest male on the beach, drive him away, and take his harem. That might work if a male was also big, but if he was small it was a strategy doomed to failure. So perhaps instead he might skulk at the edges of the colony and mate secretly with females from time to time, trying to avoid getting killed by the harem leader. Its not a solution guaranteed to produce a lot of kids. But Maynard Smith showed that its also not necessarily a one-way ticket to extinction. Instead, its possible that the two strategies, one dominant and one minor, can come to a stable coexistence.

Scientists have found lots of these so-called evolutionarily stable stategies. Some male salmons who take the sneaky route actually commit their whole bodies to the strategy. Instead of bulking up their bodies and developing big sexual displays such as long jaws, they become small and invest their energies into growing massive testes that give them a large enough supply of sperm to make the most of their few tristes. Some evolutionarily stable stragies cycle from prominence to rareness and back over time, in a sort of rock-scissors-paper game. Bacteria may reach evolutionarily stable strategies that leave some of them killers and others harmless. Evolutionary stable strategies may have a lot to tell us about human behavior as well. Genes have a role in personality, intelligence, and behavior, and theres obviously a lot of variation in all these factors. Its possible that these genes have, over millions of years, reached an evolutionarily stable state with one another. And these games may also be a model for how something as peculiar as cooperation evolved in our own species. (You can read a good recent review of evolutionary games written by Martin Nowak here.)

Maynard Smith realized that some of the equations that he developed for these sorts of social interactions might also carry over to more fundamental questions about the evolution of life. When life was just getting started on Earth, for example, genes might have settled into certain strategies for getting replicatedarranged on chromosomes, for example--in the same way animals settle into strategies for surviving. Maynard Smith came to see the history of life as a series of transitions to new ways of processing information--from the origin of life to the first sexually reproducing cells to the appearance of multicellular life to the emergence of animal societies, and finally, human language and culture. Each new transition created a new playing field for a new set of games.

All this may sound a bit daunting, but Maynard Smith was gifted with a disarmingly simple way of explaining his ideas. Check out his final book, The Origins of Life, to see what I mean.

Update 4/22: The obits are emerging now.

Update 4/23: The definitive JMS site. Via Panda's Thumb.