The world has one fewer voice of reason following the death of Stephen Jay Gould, who died from cancer on Monday 20 May 2002 at the age of 60. His writings on evolution were some of the most powerful tools available against the nonsense of creationism and its associated attempts to disguise religion as science. (Only one version of religion, of course. There are many religions, each with its own creation story.)
Two aspects of Professor Gould's life illustrated what it means to be a scientist and to do science. Gould's speciality was evolution, and the conventional wisdom was (and still is to a large extent) that evolution is a gradual process that happens over many millions of years. Gould challenged this orthodoxy by suggesting a mechanism he called "punctuated equilibrium", where evolutionary jumps happen over relatively short periods with long periods of inactivity in between. I should point out that "short periods" here still means tens or even hundreds of thousands of years – nothing happens overnight. The creationists used to love to cite Gould as an example of how scientists could not agree about evolution, implying that this meant that the theory was damaged somehow. Reality is, however, that the scientific arguments were about process not fact, and showed how real science can accommodate differing opinions if the evidence is ambiguous. There is no disagreement about the fact of evolution, only about the details of how it happens. Opponents of science love to cite Gould and other "dissenter" scientists like Barry Marshall (bacteria cause stomach ulcers), Galileo (heliocentricity) and Ignatz Semmelweis (doctors washing hands) as if their experiences somehow validate people like Emmanuel Velikovsky, Andrew Wakefield and the plethora of cancer quacks and free-energy experts. The difference is evidence. Science allows dissent if there is evidence to support it, but just because some dissenters have been proved right does not prove that they all are. Gould may be proved wrong about punctuated equilibrium one day, and had he lived I am sure he would have been disappointed, but I am equally sure that, as a scientist, he would have accepted the decision gracefully.
The second thing from Gould's life that showed what it means to be a scientist was the way he reacted in 1982 to the diagnosis that he had abdominal mesothelioma. (This was not the cancer that finally killed him.) Faced with the news that the median life expectancy following diagnosis was eight months, he set out to find out what this forecast really meant. In an essay called The Median Isn't the Message he talked about how the misunderstanding of statistics can lead people to false expectations and incorrect decisions. Anyone with more than a passing familiarity with The Millenium Project will be aware of my utter contempt for people who peddle false cures for cancer. Gould's essay not only points out the natural variability in the course of disease which allows the vultures to claim success when all that happened is that the patient was in the right-hand-side of the distribution, but the clear, accessible language makes it something which can provide facts and encouragement to people faced with their own personal medical crises. Again I emphasise that what Gould did shows how science works – he admitted to being frightened, but he sought facts and evidence to counter the emotion.
I have several of Gould's books and I make no secret of the fact that he is one of the reasons I believe many of the things I believe. (Actually, it is not "he" that is the reason, but the arguments he put forward.) I don't agree with everything he wrote (I think he tried too hard to make some of the points in The Mismeasure of Man, for example), but that doesn't mean either of us is wrong. His final work, The Structure of Evolutionary Theory, was released in March 2002. I haven't read it yet and I am told that it is not an easy read, but I expect that I will make the effort. I owe that to the author.
Here are several books by Stephen Jay Gould. His works remain to carry on the fight against creationism and other attacks on science and reason.