Alfred Russel Wallace: a life by Peter Raby

The natural selection of scientists

PEOPLE LIKE stories about people, and most histories are full of tales of great individuals who change the world. This is as true of scientific histories as any other, and many scientists are as tempted as lay people by images of towering geniuses who revolutionise their craft.

The truth is very different. Science progresses incrementally, hand in hand with technology, with each small step building on the work of many predecessors, and discoveries often made more or less simultaneously by two (or more) independent researchers when the time is ripe. What makes scientific geniuses special is that they often make contributions in more than one area, and perceive the broad picture into which those contributions fit.

All of this is amply born out by Peter Raby's splendid biography of Alfred Russel Wallace, the man who independently hit upon the idea of natural selection, and thereby prompted Charles Darwin to go public with his own version of the theory. Wallace was never the neglected figure of the evolution story, and during his lifetime (which lasted until 1913) he received many honours and attained a high profile ­ which, unfortunately, resulted in no small measure from his espousal of spiritualism and other activities which, if anything, detracted from his standing as a scientist.

He also insisted, especially in later life, that humankind somehow transcended the laws of evolution. But he did have the one brilliant insight about natural selection as the mechanism of evolution. The fact of evolution was already well-established by the 1850s, for those with eyes to see; the mechanism was the puzzle solved by Darwin and Wallace.

By contrast, Darwin made important contributions to geology, the biology of molluscs and plants, put people in their proper evolutionary place, and marshalled a huge weight of evidence in support of his case. As Raby makes clear, Darwin was Wallace's superior both as a naturalist and as a thinker. He also had the benefit of birth into the privileged classes, and never had to worry about money. Wallace did not exactly emerge from poverty, but from an impoverished middle-class family. He had to make his own way in the world, and can be seen as an archetypal Victorian product of industry and determination.

This is much more a tale of travel and adventure than of science, although Raby does give a balanced account of the response of Darwin and his friends in the scientific establishment to the letter from Wallace (then in the East Indies) which set out his ideas on natural selection, duplicating Darwin's own. The joint publication of papers by Darwin and Wallace in 1858 resolved the situation creditably, and Wallace was always happy with the outcome. Although various conspiracy theories alleging dastardly work by Darwin have emerged since, they are suitably exploded by Raby.

Even without his contribution to the theory of natural selection, Wallace's life would be fascinating enough, from his early struggles to achieve financial independence during the first railway boom to his travels in South America (followed by a fire at sea which cost him his collections and almost his life), his years in the East Indies and his long later life back in England. He was active in a kind of mild socialism as well a kind of mad spiritualism, married a girl half his age, and only had financial troubles in old age because of his obsession with building houses (the last completed just before his 80th birthday).

As for the relative scientific standing of Wallace and Darwin, who better than Wallace to have the last word with his comments on The Origin of Species: "I really feel thankful that it has not been left to me to give the theory to the world. Mr Darwin has created a new science and a new philosophy; and I believe that never has such a complete illustration of a new branch of human knowledge been due to the labours and researches of a single man."

The reviewer is the author of 'Almost Everyone's Guide to Science' (Phoenix).