1Charles Darwin had drawn a tree in a notebook and shut it in a drawer. Now hear what was in the drawer, and why he feared it, and what at last forced it open.
2The tree said that the kinds of living things were not made separately. They were cousins. The finch with the thick beak and the finch with the thin one had a grandmother in common. Go back far enough and the finch and the hawk had one. Go back further, and the bird and the lizard. Further still, and everything that breathes or crawls or flowers. All life was one family, and its history was one tree, branching and branching from a single root.
3He had the shape. He did not yet have the cause. What made a branch divide? What could turn one kind of finch into two?
4A year after he drew the tree he was reading, for his rest, a book about the numbers of people. It was by a clergyman named Malthus. It said that people, like all creatures, bring forth more young than the land can feed, so that there is always a struggle for a place at the table.
5Charles put the book down. He had seen it on every shore he had walked, and never looked at it straight. A single oyster casts a million eggs. Yet the world is not buried in oysters. So nearly all that are born must die young. Which ones live?
6Not the same as the ones that die. No two creatures in a nest are quite alike. One has a beak a hair thicker. In a year when the only seeds are hard seeds, that hair is the difference between eating and starving. The thick-beaked ones live and have young, and their young have thick beaks. Nothing chooses. No one plans it. The dying does the choosing. Give that as many years as Mary Anning's cliff had, and it would make a new kind of bird out of an old one, as surely as rain makes a valley.
7He had it whole when he was twenty-nine. It was simple enough to tell a child. It frightened him so much that it made him ill.
8For think what it meant in that time. It meant no kind of creature had been shaped by hand for its place. It meant the cruel waste of nature, the thousand deaths for each life, was not a flaw in the plan but the working of it. And it meant, though he hardly dared write it even in private, that people too were a twig on that tree.
9He had another reason, and her name was Emma. She was his cousin, and he married her in that same season. She believed with her whole heart in the faith of her fathers. Before the wedding he told her honestly where his thoughts were tending. She did not turn from him. But she wrote him a letter. She said she was afraid, not of his doubts, but that a habit of believing nothing until it was proved might close him to things that cannot be proved in the same way. And she could not bear to think that they would not belong to each other for ever.
10He kept that letter all his life. Long after, when he was old, he wrote on the bottom of it that he had kissed it and wept over it many times.
11So he did not publish. He wrote his idea out, in two hundred pages. He sealed it with a note to Emma: if he died suddenly, she was to find a good editor and pay to have it printed. Then he put it in the drawer. To one trusted friend, a student of plants, he wrote that he had come to believe the kinds of living things were not fixed for ever. He said that telling it was "like confessing a murder."
12They moved to a quiet house in a village in Kent. He was ill most days, with a sickness of the stomach that no doctor could name. He walked the same sandy path round the same small wood every noon, and kicked a flint off a pile at each turn to keep the count.
13Children came, ten in all. The one who had most of his heart was the second, a girl named Annie. She was the child who would smooth his hair, and walk the sandy path beside him, turning on her toes. When she was ten she began to sicken. He took her to a town in the hills where the water was thought to heal.
14He sat by Annie's bed for a week. She thanked him each time he gave her water. Then she died, at noon, in the spring of the year.
15He wrote to Emma that same hour. A week later he wrote down everything he could remember of the child, so that he would not lose her face, and then he could never afterward bear to read it. He did not go to the burial. He went home to Emma.
16Something in him closed that spring that had been open. After that he did not look for comfort where Emma found it. He never mocked her for finding it, and she never ceased to pray for him. They were as close as two people can be, and in that one matter they sat on either side of a wall of glass.
17And still he did not publish. He spent eight years on barnacles. He cut up thousands of them under a lens, and wrote four thick books that hardly anyone would read.
18He told himself he was earning the right to speak, and that was partly so. But the truth is that he was afraid. Twenty years went by from the tree in the notebook. His friends who knew the secret begged him to print before someone else did. He began a great book that would hold every proof. He had written a quarter of a million words and was not half done.
19Then, one morning in early summer, the post brought a thin packet from the other side of the world.
20It came from an island in the far spice seas, and it was from a man named Alfred Wallace.
21You should know who he was. He was fourteen years the younger. He had left school at fourteen and worked as a builder's boy and a measurer of land. He had taught himself the names of plants and beetles from cheap books, and gone out to the great forests of the Amazon to collect creatures and sell them. After four years he sailed for home with everything he had gathered. In the middle of the ocean the ship caught fire. He stood on the burning deck and watched his notes, his drawings, and four years of creatures go up in flame. Then he sat in an open boat for ten days, before a passing ship found them.
22Wallace was home for a year and a half, and then he went out again, to the islands between Asia and Australia. He stayed eight years. He was one of the first of his people to watch the birds of paradise alive and dancing in their trees.
23He and Darwin had written to each other a little. Each knew the other was thinking about how kinds begin. Neither had said how far he had got.
24In that packet was an essay of some twenty pages. Wallace wrote that it had come to him while he lay shaking with fever in a hut. Between the cold fit and the hot, he had been thinking of the clergyman Malthus and his book. And he had seen it. More are born than can live. They differ. The ones better fitted stay, and hand their fitness on. He had written it out in two evenings. Would Mr Darwin be kind enough to look at it and, if he thought it worth anything, pass it on to the great Lyell?
25Darwin read it. It was his own theory. It was not like his theory; it was the thing itself, down to the turns of phrase. If Wallace had held the pages from the drawer in his hand, Darwin said, he could not have made a better short account of them. Twenty years of work, and a younger man had got there in two evenings and a fever.
26Now see the doors that stood before him that morning.
27He could do nothing. Letters from those seas were lost every month. No one living knew this one had come.
28He could wait a little, and hurry his own pages into print, and send Wallace's on later with regrets for the delay.
29Or he could do what the letter asked.
30He sent it to Lyell that same day. With it he wrote that all his claim to have been first, whatever that was worth, would now be broken. He wrote that he would far sooner burn his whole book than have Wallace or anyone think he had behaved in a paltry spirit. He asked his friends to judge, for he could not trust himself to.
31And he could not think about it longer. For in that same week the scarlet fever came into the village. Then the baby took the fever. He was the last of the ten, a child of a year and a half who had not yet learned to walk or speak, and who was very sweet and placid. He died after a few days.
32So Lyell and the plant-man settled it between them, as fairly as they could. Three days after the baby's death there was a meeting in London of a society of men who studied living things. Both men's words were read out there, side by side: some pages from Darwin's drawer, with their dates, and then the essay from the islands. Neither man was in the room. Wallace was on the far side of the world and knew nothing of it. Darwin was in a country churchyard, burying his son.
33Thirty people or so heard the reading. No one argued. No one seemed much stirred. At the end of the year, the president of that society looked back over its meetings and said the year had not been marked by any of those great discoveries that change a science all at once.
34Be fair in judging this, as those men tried to be fair. Wallace was not asked before his essay was read beside another's. He could not be; a letter took months. When the news reached him in his forest he might well have felt that the rich man with powerful friends had been set ahead of him. He did not. He wrote home that he was proud to have had any part in it. For the rest of his long life he called the theory by Darwin's name. He said that he had seen it in a flash, and Darwin had given twenty years to it, and the twenty years were what made the world believe.
35And Darwin, for his part, never once let anyone forget that there had been two of them. Each of them guarded the other's share. It is a rare thing among people who find the same treasure on the same day.
36Now he wrote like a man with a fire behind him. The great book was put aside. In thirteen months he made a shorter one, and it was the best thing he ever wrote. When it was done he went to the hills to take the waters, and waited there for the storm.
37The book came out at the end of autumn. The booksellers took every copy on the first day.
38Then the storm came, and it has not altogether ended. His old captain, FitzRoy, stood up at a great public meeting holding a Bible over his head, and begged the people to believe God and not the man he had carried round the world. But others, and there were many of faith among them, said that a Maker who made a world able to make itself was greater, not less. Emma read every page before it was printed, and marked the places where he had not been clear. She did not agree with him. She made his argument stronger all the same.
39In the whole book there is only one picture. It is the tree. It shows a few lines at the bottom, and from them branches rising and forking and forking again. Most of the branches stop short. Those are the kinds that died, the fish-lizards and the giant sloths. A few run on to the top of the page, and divide as they go.
40What does the tree do? It spreads. Where there was one kind there come to be two, and then ten, each living in its own way: one on hard seeds, one on flies, one in the sea, one in the dark. Every fork is a new way of being alive that was not in the world before. No one sends it there. Life pushes into every room that stands empty.
41He said so himself, in the last words of the book. He spoke of the planet circling on by the fixed law that Newton found. And he said that, all the while, "from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."
42He had been afraid for twenty years of a thing that turned out, when at last he looked at it steadily, to be a kind of praise.
43Wallace outlived him by thirty years and was one of those who carried his coffin.
44So now the century held two great pictures, and it could not make them fit.
45One was the engine. Heat falls from hot to cold, and never climbs back, and whatever is lost in the falling is lost. That picture runs downhill.
46The other was the tree. Life begins as one small thing and becomes ten thousand, each finer and stranger than the last. That picture climbs.
47How could both be true in one world? How does anything rise in a world where heat only falls? Few had yet thought to ask. The man who would ask it was at that time a schoolboy in Austria, practising the piano. But first someone had to give the falling its name.