A short history of nearly everything

of the century, they showed no sign of it. No discussion followed. Nor did the event attract much notice elsewhere. Darwin cheerfully later noted that only one person, a Professor Haughton of Dublin, mentioned the two papers in print and his conclusion was “that all that was new in them was false, and what was true was old.”

Wallace, still in the distant East, learned of these maneuverings long after the event, but was remarkably equable and seemed pleased to have been included at all. He even referred to the theory forever after as “Darwinism.” Much less amenable to Darwin’s claim of priority was a Scottish gardener named Patrick Matthew who had, rather remarkably, also come up with the principles of natural selection-in fact, in the very year that Darwin had set sail in the Beagle. Unfortunately, Matthew had published these views in a book called Naval Timber and Arboriculture, which had been missed not just by Darwin, but by the entire world. Matthew kicked up in a lively manner, with a letter to Gardener’s Chronicle, when he saw Darwin gaining credit everywhere for an idea that really was his. Darwin apologized without hesitation, though he did note for the record: “I think that no one will feel surprised that neither I, nor apparently any other naturalist, has heard of Mr. Matthew’s views, considering how briefly they are given, and they appeared in the Appendix to a work on Naval Timber and Arboriculture.”

Wallace continued for another fifty years as a naturalist and thinker, occasionally a very good one, but increasingly fell from scientific favor by taking up dubious interests such as spiritualism and the possibility of life existing elsewhere in the universe. So the theory became, essentially by default, Darwin’s alone.

Darwin never ceased being tormented by his ideas. He referred to himself as “the Devil’s Chaplain” and said that revealing the theory felt “like confessing a murder.” Apart from all else, he knew it deeply pained his beloved and pious wife. Even so, he set to work at once expanding his manuscript into a book-length work. Provisionally he called it An Abstract of an Essay on the Origin of Species and Varieties through Natural Selection-a title so tepid and tentative that his publisher, John Murray, decided to issue just five hundred copies. But once presented with the manuscript, and a slightly more arresting title, Murray reconsidered and increased the initial print run to 1,250.

On the Origin of Species was an immediate commercial success, but rather less of a critical one. Darwin’s theory presented two intractable difficulties. It needed far more time than Lord Kelvin was willing to concede, and it was scarcely supported by fossil evidence. Where, asked Darwin’s more thoughtful critics, were the transitional forms that his theory so clearly called for? If new species were continuously evolving, then there ought to be lots of intermediate forms scattered across the fossil record, but there were not.[43] In fact, the record as it existed then (and for a long time afterward) showed no life at all right up to the moment of the famous Cambrian explosion.

But now here was Darwin, without any evidence, insisting that the earlier seas must have had abundant life and that we just hadn’t found it yet because, for whatever reason, it hadn’t been preserved. It simply could not be otherwise, Darwin maintained. “The case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained,” he allowed most candidly, but he refused to entertain an alternative possibility. By way of explanation he speculated-inventively but incorrectly-that perhaps the Precambrian seas had been too clear to lay down sediments and thus had preserved no fossils.

Even Darwin’s closest friends were troubled by the blitheness of some of his assertions. Adam Sedgwick, who had taught Darwin at Cambridge and taken him on a geological tour of Wales in 1831, said the book gave him “more pain than pleasure.” Louis Agassiz dismissed it as poor conjecture. Even Lyell concluded gloomily: “Darwin goes too far.”

T. H. Huxley disliked Darwin’s insistence on huge amounts of geological time because he was a saltationist, which is to say a believer in the idea that evolutionary changes happen not gradually but suddenly. Saltationists (the word comes from the Latin for “leap”) couldn’t accept that complicated organs could ever emerge in slow stages. What good, after all, is one-tenth of a wing or half an eye? Such organs, they thought, only made sense if they appeared in a finished state.

The belief was surprising in as radical a spirit as Huxley because it closely recalled a very conservative religious notion first put forward by the English theologian William Paley in 1802 and known as argument from design. Paley contended that if you found a pocket watch on the ground, even if you had never seen such a thing before, you would instantly perceive that it had been made by an intelligent entity. So it was, he believed, with nature: its complexity was proof of its design. The notion was a powerful one in the nineteenth century, and it gave Darwin trouble too. “The eye to this day gives me a cold shudder,” he acknowledged in a letter to a friend. In the Origin he conceded that it “seems, I freely confess, absurd in the highest possible degree” that natural selection could produce such an instrument in gradual steps.

Even so, and to the unending exasperation of his supporters, Darwin not only insisted that all change was gradual, but in nearly every edition of Origin he stepped up the amount of time he supposed necessary to allow evolution to progress, which pushed his ideas increasingly out of favor. “Eventually,” according to the scientist and historian Jeffrey Schwartz, “Darwin lost virtually all the support that still remained among the ranks of fellow natural historians and geologists.”

Ironically, considering that Darwin called his book On the Origin of Species, the one thing he couldn’t explain was how species originated. Darwin’s theory suggested a mechanism for how a species might become stronger or better or faster-in a word, fitter-but gave no indication of how it might throw up a new species. A Scottish engineer, Fleeming Jenkin, considered the problem and noted an important flaw in Darwin’s argument. Darwin believed that any beneficial trait that arose in one generation would be passed on to subsequent generations, thus strengthening the species.

Jenkin pointed out that a favorable trait in one parent wouldn’t become dominant in succeeding generations, but in fact would be diluted through blending. If you pour whiskey into a tumbler of water, you don’t make the whiskey stronger, you make it weaker. And if you pour that dilute solution into another glass of water, it becomes weaker still. In the same way, any favorable trait introduced by one parent would be successively watered down by subsequent matings until it ceased to be apparent at all. Thus Darwin’s theory was not a recipe for change, but for constancy. Lucky flukes might arise from time to time, but they would soon vanish under the general impulse to bring everything back to a stable mediocrity. If natural selection were to work, some alternative, unconsidered mechanism was required.

Unknown to Darwin and everyone else, eight hundred miles away in a tranquil corner of Middle Europe a retiring monk named Gregor Mendel was coming up with the solution.

Mendel was born in 1822 to a humble farming family in a backwater of the Austrian empire in what is now the Czech Republic. Schoolbooks once portrayed him as a simple but observant provincial monk whose discoveries were largely serendipitous-the result of noticing some interesting traits of inheritance while pottering about with pea plants in the monastery’s kitchen garden. In fact, Mendel was a trained scientist-he had studied physics and mathematics at the Olmutz Philosophical Institute and the University of Vienna-and he brought scientific discipline to all he did. Moreover, the monastery at Brno where he lived from 1843 was known as a learned institution. It had a library of twenty thousand books and a tradition of careful scientific investigation.

Before embarking on his experiments, Mendel spent two years preparing his control specimens, seven varieties of pea, to make sure they bred true. Then, helped by two full-time assistants, he repeatedly bred and crossbred hybrids from thirty thousand pea plants. It was delicate work, requiring them to take the most exacting pains to avoid accidental cross-fertilization and to note every slight variation in the growth and appearance of seeds, pods, leaves, stems, and flowers. Mendel knew what he was doing.

He never used the word gene-it wasn’t coined until 1913, in an English medical dictionary-though he did invent the terms dominant and recessive. What he established was that every seed contained two “factors” or “elemente,” as he called them-a dominant one and a recessive one-and these factors, when combined, produced predictable patterns of inheritance.

The results he converted into precise mathematical formulae. Altogether Mendel spent eight years on the experiments, then confirmed his results with similar experiments on flowers, corn, and other plants. If anything, Mendel was too scientific in his approach, for when he presented his findings at the February and March meetings of the Natural History Society of Brno in 1865, the audience of about forty listened