Most of us know the story. A young man sails round the world, sees finches in the Galapagos whose beaks differ from island to island, and realises in a flash that species change. He comes home and writes a book saying that human beings are descended from apes. The Church is outraged. The phrase is survival of the fittest, and the theory is called evolution.
Nearly every clause of that is wrong. The first edition of On the Origin of Species never uses the word evolution, never says survival of the fittest, and never mentions apes. It mentions pigeons a hundred and twelve times. And the real question about Darwin is not what he saw in the Galapagos. It is why he waited twenty-one years.
The islands
The Beagle sailed from Devonport on 27 December 1831 and came home to Falmouth on 2 October 1836. In the Galapagos the young Darwin collected hard and well, fell off tortoises, and had no theory to organise any of it.
The key fact was handed to him by the vice-governor, an Englishman named Lawson, who said he could tell which island any tortoise came from. Darwin, by his own account, did not pay sufficient attention, and had already mixed up the collections from two of the islands. There was no flash.
The finches mattered only later, in London, when the ornithologist John Gould sorted the birds Darwin had brought home as a mixed bag of wrens, finches and blackbirds, and found them a closely related group of ground finches found nowhere else on earth. Somebody else did the sorting.
The notebook
In July 1837 Darwin opened a pocket notebook on what he called the transmutation of species. On one page he drew a small branching tree, with two words above it: I think. He was twenty-eight.
On 28 September 1838 he read Malthus on population and saw the mechanism: in a world where most of what is born dies, small favourable differences would be preserved and unfavourable ones destroyed. Six weeks later he proposed to his cousin, Emma Wedgwood.
The letter to Emma
In 1842 he wrote the theory out in thirty-five pages of pencil. In 1844 he expanded it into a 230-page essay, made a fair copy, and on 5 July wrote his wife a letter telling her what to do with it if he died suddenly: spend four hundred pounds having it published, and here are the men who might edit it.
He did not die. He put it away.
Twenty-one years
The usual explanation is fear, of the Church, of scandal, of his wife's feelings. All of that is real, and it is not enough. The better answer is that natural selection cannot be seen. Nobody has ever watched one species turn into another. It could not be demonstrated, only argued, from a thousand facts that fit it and no other explanation.
So he spent the years building the case. Eight years dissecting barnacles. Three years breeding pigeons and sitting in public houses with the men who bred them. Months rotting seeds in salt water in his cellar, to see whether they could cross an ocean. A correspondence with farmers, gardeners and breeders that ran to thousands of letters. All from a house in Kent he called ugly, a few hours a day, for forty years, while ill.
The parcel from Ternate
On 18 June 1858 a letter reached Down from Alfred Russel Wallace, a collector in the Malay archipelago whom Darwin had never met, with an essay setting out the same idea. Darwin wrote to his friend Charles Lyell that his originality would be smashed.
His friends arranged for both men's work to be read together at the Linnean Society on 1 July. Darwin did not attend; his infant son had died of scarlet fever three days before. In little more than a year he wrote an abstract of the book he had meant to spend his life on. On the Origin of Species was published on 24 November 1859.
The word he would not use
The last word of the book is evolved. The noun does not appear; in 1859 it meant something else. His own phrase was descent with modification, which says what happens and promises nothing about progress. Survival of the fittest is Herbert Spencer's, taken in at Wallace's urging in the fifth edition, ten years on.
And he did not win in his lifetime, not on the part that was his. Common descent was accepted within a decade. Natural selection was doubted and widely set aside for two generations, until genetics rescued it in the 1920s and 1930s. He never knew it had worked. Today it is why bacteria stop responding to antibiotics, and why the course has to be finished.
Everything on this page comes from Charles Darwin: Where Species Come From, which is built from the letters and the printed texts, and says in its notes where each fact comes from.
