John Maynard Smith, 84; Applied Game Theory to Evolution, Asked Why Animals Developed Sex

Times Staff Writer

John Maynard Smith, one of the most influential evolutionary biologists of the latter part of the 20th century, has died. He was 84.

Diagnosed with lung cancer more than a year ago, Maynard Smith died Monday at his home in southeast England, sitting in his high-backed chair and surrounded by his books.

Famed principally for applying a mathematical approach known as game theory to the study of evolution and his work on the evolution of sex, Maynard Smith is credited by colleagues with influencing evolutionary thought on broad areas in the life sciences.


“There is scarcely a branch of evolutionary or population genetic theory that has not been illuminated by his vivid and versatile inventiveness,” evolutionary biologist and author Richard Dawkins wrote in 1993. He was one of many scientists who credited Maynard Smith’s writings with sparking their interest in the field.

In his principal scientific contribution, Maynard Smith showed that game theory, a branch of mathematics that had previously been applied to economics, could be used to explain many aspects of animal behavior.

It could predict when a creature should fight and when it should back down, or when a male bird should stick around and help care for his young and when he would be better off abandoning the nest for a new mate, and myriad other behavioral choices.

Species, he argued, evolved what he termed “evolutionarily stable strategies” -- rules for responding to circumstances that remained stable in a population, because creatures that deviated from the rules were at a disadvantage.

In another substantial contribution, Maynard Smith tackled the mystery of why creatures evolved to have sex. This is a conundrum in evolutionary biology, because organisms that reproduce “clonally” -- that is, by making exact replicas of themselves without a genetic contribution from a male -- contribute more of their genes to the next generation and should therefore be at a selective advantage.

“Maynard Smith deeply wanted to understand why there are males around -- why on Earth do you need males? Why didn’t you just have a population of females?” said Paul Harvey, head of the department of zoology at the University of Oxford. “He gave us all the logical tools for exploring what the answers might be.”

In his influential 1978 book “The Evolution of Sex,” Maynard Smith clearly laid out the problem and its possible theoretical solutions: for instance, two parents might be needed to help rear the young. Or it might be beneficial to mix up genes, via sex, to keep a species genetically varied and able to respond to changes in the world.

The solution remains a mystery.

He was born Jan. 6, 1920, in London, but spent much of his youth on and around the moors of southwest England, developing a keen interest in bird-watching and beetle-collecting as a child.

He was educated at the exclusive private boys school Eton College, an environment he disliked for its “snobbish” and “anti-intellectual” atmosphere -- but he credited it with teaching him mathematics very well and influencing his course in life. He noticed that his schoolmasters spoke with special contempt of another former Etonian, the famed biologist J.B.S. Haldane, whom they reviled as an atheist, divorcee and socialist.

“I remember thinking, ‘Anybody they hate that much can’t be all bad. I must go and find out about him,’ ” Maynard Smith said in a 2000 interview with Natural History magazine.

Refusing to join his family’s stockbroker business, he studied engineering at Cambridge University, and during that time he joined the Communist Party. He broke ranks with the party by trying to sign up for the army during World War II; he was rejected because of poor eyesight. He eventually resigned from the party, though he retained a leftist perspective throughout his life.

After researching stress in aircraft design during the war, he returned to study zoology at University College London, where Haldane was a professor. He worked with Haldane until 1965, when Maynard Smith became first dean of the new school of life sciences at the University of Sussex.

Officially retired from Sussex since 1985, he remained scientifically productive for decades afterward. Just days before his death, colleagues said, he was busy completing a manuscript on the evolution of religion and pursuing studies on the evolutionary genetics of disease-causing bacteria.

An approachable man with unruly white hair and thick glasses, Maynard Smith was remembered by colleagues and friends as a charismatic speaker but deadly debater, a lover of nature and an avid gardener, and a man who enjoyed nothing better than discussing scientific ideas with young researchers over a glass of beer in a pub.

“He was one of the most gracious people in the field; he made time for everyone, from the most famous to the lowliest graduate student,” said Montgomery Slatkin, a professor in the department of integrative biology at UC Berkeley. “He’d go out with the graduate students, listen patiently to what they were working on and offer his help ... and managed to make everybody feel he was a good friend.”

Among his awards, Maynard Smith was a joint recipient of the 1999 Crafoord Prize, equivalent in stature to a Nobel, and the 2001 Kyoto Prize, Japan’s highest lifetime achievement award. He was a fellow of Britain’s Royal Society and was awarded the society’s 1986 Darwin Medal and 1997 Royal Medal.

He was the author of hundreds of academic papers and 14 books, including “The Theory of Evolution” (1958), “The Evolution of Sex” (1978) and “Evolution and the Theory of Games” (1982).

Smith is survived by his wife, Sheila, two sons and a daughter.