John Maynard Smith, biologist

B. January 6 1920; died April 19 2004

Read the Obituary by David Harper in The Guardian, 22 Apr 2004. And see his homepage at Univ. Sussex.

"...JMS helped to illuminate so many areas in biology that it is hard to know where to begin." "By introducing mathematical models from game theory into the study of behaviour, he showed that the success of an individual's behaviour often depends on what other individuals do. He introduced the idea of an "evolutionarily stable strategy": a strategy that, once common, cannot be bettered by alternatives. This work has completely revolutionised the way biologists think about behavioural evolution, and game theory is now one of the most commonly used tools in evolutionary thinking."

"JMS also tackled one of the most vexed - but superficially least obvious - conundrums of evolutionary biology: why has sex evolved? His book The Evolution Of Sex (1978) pointed out "the twofold cost of sex". One way to understand this cost is to notice that sexually reproducing organisms must produce both female and male offspring, whereas asexual, or clonal, organisms need only produce females. Since in most sexual populations around half the offspring produced are male, an asexual population with the same fecundity will produce twice as many daughters. This advantage applies generation after generation, seemingly providing a huge evolutionary advantage to clonal reproduction. Thus the problem is: why do we see so much sex in the world?

Like his mentor, Haldane, JMS was deeply committed to making evolutionary ideas accessible to a wide audience. His "little Penguin", The Theory Of Evolution (1958, 1966, 1975, 1993), inspired many leading researchers to become biologists.

Despite his fame, he would nevertheless take time to discuss ideas with undergraduate students and eminent professors alike. He displayed almost limitless intellectual energy, even in his 80s. On one recent occasion, a junior researcher from another university sent him a paper and included a question with it. Within a day, JMS had written three pages of detailed notes and calculations, to the questioner's surprise and appreciation."