Read The Reluctant Mr. Darwin Online
Authors: David Quammen
But something had changed. Wallace's lost letter may have contained a declaration of transmutationist views, and maybe also a boast that his paper was just the first step toward an explanatory theory. Such news would have put Darwin on guard. In any case Darwin knew that Wallace, consciously or not, was noodling along the edges of transmutationism. How consciously, how fruitfully? Those were separate questions, which Darwin doesn't seem to have asked. Seeing the younger man as a diligent but unsophisticated field naturalist and a possible but unlikely competitor, he was happy to share facts and vague musings, and careful to get more than he gave. Several other factors, in the meantime, had affected Darwin's state of mind.
First, he had grown more impatient to reveal his big secret. He confessed to his old chum Fox, a non-scientist, that his present work involved the question whether species are immutable or not. (He knew his own answer to that but pretended to be uncertain.) He hoped to produce a book on the subject within a few years, he told Fox. With several scientific colleagues he went further, admitting his conviction that species do transmutate and outlining his theory. Joseph Hooker was already in the know, having by now read Darwin's unpublished 1844 essay, but early in 1856 Darwin revealed his thinking to Charles Lyell and two or three others, including T. H. Huxley, the brilliant anatomist and popular lecturer who taught natural history in London. Huxley and Hooker and their wives, along with one other scientist, paid the Darwins a weekend visit at Down House in April, during which the host spilled his beans about natural selection. Skeptical of religion, argumentative by nature, Huxley greeted Darwin's wild idea with wild enthusiasm but managed to keep the secret when he went back to London. Lyell and his wife also visited the Darwins for a few days that month, and on the morning of April 16 the two men had a quiet talk. Darwin laid out his heretical, ingenious theory. He must have gulped hard first, given that Lyell had lambasted Lamarckian transmutationism in
Principles of Geology
. Lyell's reaction was strong but complicated, reflecting both his intellectual courage and his attunement to the imperatives of a scientific career. He didn't accept Darwin's notion, not yet. He did recognize its power and importance. In a private journal of his own, devoted to the species question, Lyell faithfully summarized that day's discussion. Remembering what Wallace called the “law” of closely allied species appearing adjacent in space and time, Lyell acknowledged that Darwin's theory of natural selection seemed to explain it. He sensed that these two hounds were running the same hare.
The second new factor in Darwin's mental mix was that Lyell gave him some pointed advice: Publish. Enough delay, enough caution, enough perfectionism. Go to press. “I wish you would publish some small fragment of your data,” Sir Charles wrote shortly after the visit; “
pigeons
if you please & so out with the theory & let it take dateâ& be citedâ& understood.” He was still a creationist himself, but also a loyal friend. Vicariously, on Darwin's behalf, he felt the urgency to announce this great discoveryâor anyway, this dramatic ideaâand claim credit.
Darwin promised to consider Lyell's suggestion. But he was reluctant and, as he admitted, confused. To come “out with the theory”âthat was easier said than done. How could he do justice, in a hasty synopsis, to such a provocative and complicated set of facts, inferences, and concepts? How could he make the theory persuasive without presenting all his evidence? How could he answer preemptively all the objections he expected? And what was the rush? He felt strung between scientific ideals and scientific ambition. “I rather hate the idea of writing for priority,” he told Lyell, “yet I certainly shd. be vexed if any one were to publish my doctrines before me.” That sentence captures it: He hated the idea of writing for priority, but dammit he did want priority.
A week later he wrote to Hooker, his closest friend, with whom he could be even more candid. “I had a good talk with Lyell about my species work, & he urges me strongly to publish something.” A journal article covering part of the subject, for instance. Or I might do a very thin volume, Darwin said, except that it's “dreadfully unphilosophical” to publish such a thing without detailed factual support and references. He didn't want his work to look glib and racy, like
Vestiges of the Natural History of Creation
. “But Lyell seemed to think I might do this, at the suggestion of friends,” he told Hooker, “& on the ground which I might state that I had been at work for 18 years, & yet could not publish for several years.” The special pleading had begun.
He “could not publish” for several years. Why? Because he was cautious and methodical and hadn't yet set himself to the writing. Because he had chosen to proceed slowly. Now he was of two minds: He wanted to put something on record, for the sake of claiming priority, and he wanted to delay publication, for the sake of better preparing his case. He wanted to do it for his own peace of mind, but he preferred to say that he'd been persuaded by friends. Over the full sweep of his life, Charles Darwin was a man of great integrity, great goodness, deep generosity, and considerable courage; this episode puts his strengths in relief by showing him in some of his weakest, least forthright moments.
Hooker's reply, which also hasn't survived, argued against Lyell's suggestion of a journal article, though not necessarily against a “preliminary essay” in the form of a separate volume. A journal article, even in those days, implied some level of institutional vetting. But a little book, published privately at the author's expense, wouldn't implicate anyone except the author in its wild-eyed ideas. It wouldn't require editorial review or full citation of evidentiary sources. On the other hand, Hooker warned, releasing a slim volume now might undermine the impact of the big book that Darwin intended to publish eventually.
So the two trusted advisers offered conflicting counsel, and Darwin himself was flummoxed. He did begin drafting a short versionâcall it another essay, an article, whateverâbut he soon grew frustrated at the effort to select and reduce so severely. By late summer of 1856 he had brushed off Lyell's advice and changed his approach, writing chapter by chapter on a scale that would eventually yield several fat, exhaustive tomes commensurate to Lyell's own three-volume
Principles of Geology
. He failed to appreciate (or decided subliminally to ignore the warning signs) that young Wallace was following the same intellectual route at a pace not braked by caution.
Toward the end of the year, Darwin wrote again to Lyell: “I am working very steadily at my big Book;âI have found it quite impossible to publish any preliminary essay or sketch; but am doing my work as complete as my present materials allow, without waiting to perfect them. And this much acceleration I owe to you.” It wasn't acceleration enough.
25
Darwin and Wallace were now tenuously in touch but communicating at cross purposes through the international mails. Did the duck sent from Lombok ever make it to Darwin's dissecting bench? My guess is no, because the bird goes unmentioned after Wallace's cover note. Maybe the whole shipment of specimens went astray. Maybe it reached Samuel Stevens in a state of unpresentable rot. Anyway, no trace of a thank you appears in Darwin's otherwise unctuous letter of May 1, 1857, in which he conveyed his compliments on Wallace's “law” paper.
There's another odd comment in that letter, showing Darwin's sensitivity about how long he had delayed. After noting the similarity of their views, and the rarity of such concord between two theorizing naturalists, he stroked a dash on the page, as though clearing his throat. Then he wrote: “This summer will make the 20
th
year (!) since I opened my first notebook, on the question how & in what way do species & varieties differ from each other.” At last, Darwin intimated, he had found the answer. Anyway he'd found
an
answer, a distinct and tangible idea. Others would judge whether it was right or wrong. He couldn't possibly explain this idea in a mere letter, he told Wallace, too complicated. “I am now preparing my work for publication, but I find the subject so very large, that though I have written many chapters, I do not suppose I shall go to press for two years.” He was wheedling for time and consideration.
Although he still didn't take Wallace quite seriouslyânot seriously enoughâhe felt mildly wary. With its histrionic exclamation point, Darwin's remark was an assertion of his own interests, precedence, and claims. A male dog makes the same sort of assertion, raising his leg to mark a tree. Wallace's nose must have been off, because he didn't get the hint.
1858â1859
26
O
n or about June 18, 1858, another mailing from Alfred Wallace arrived at Darwin's front door. It came, like the others, from somewhere in the Malay Archipelago. It had been four months in transit on a series of boats. This envelope was bulkier than usual, containing a manuscript as well as a letter. Darwin opened it. Scanning the letter, reading the enclosure, he felt a nauseating surge of emotions that began with surprise and swelled quickly toward despair. His big book at this point was still a work in progress, two-thirds written and growing more unwieldy every day. Meanwhile his young pen pal, Wallace, had independently conceived the idea of evolution by natural selection.
Wallace's manuscript was titled “On the Tendency of Varieties to Depart Indefinitely from the Original Type.” It comprised about twenty pages of lucid, easy prose, written out in the author's hand. Its cardinal point, signaled in the title, was that the difference between species (as a category) and variety (as a category) is merely a difference of degree. That is, the amount of variation seen between varieties within a species is not inherently limited; rather, those increments can accumulate boundlessly until a variety splits away, becoming a distinct species unto itself. The manuscript posited “a general principle in nature” causing many varieties to do exactly that. And they don't just
split
from the parent species, Wallace asserted; they compete against it, sometimes outlive it, and eventually give rise to still other varieties differing more and more from the original type. Wallace, unlike Darwin, had coined no name for this “general principle.” But his manuscript built a case for it with logic very similar to Darwin's own.
“The life of wild animals,” Darwin read, “is a struggle for existence” in which “the weakest & least perfectly organized must always succumb.” That struggle is driven by the pressure of inherent population growth rates, yielding many more newborn individuals than can be supported by available food and habitat. Without mentioning Malthus by name, the manuscript gave a deft summary of Malthusian arithmetic. It noted that “variations from the typical form of a species” occur commonly among wild animals (as Wallace, the commercial collector, had often seen), and that most such variations “would affect, either favourably or adversely, the powers of prolonging existence.” For instance: “An antelope with shorter or weaker legs must necessarily suffer more from the attacks of the feline carnivora.” Lions would eat the slow ones. A passenger pigeon with less powerful wings would have trouble traveling widely to find food. Starvation and competition would eliminate the poor flyers. On the positive side, a giraffe with an especially long neck would have access to high leaves that the others couldn't reach. During a famine it might sustain itself with that extra resource, while short-necked giraffes died away. Those creatures “best adapted” as a result of such small differences would eat better and defend themselves better, survive better and reproduce more abundantly, establishing sizable populations while less fortunate creatures lost the struggle and disappeared. The result would be “continued divergence” over long stretches of time, with “successive variations departing further and further from the original type.” Wallace's manuscript ended with a flourish, suggesting that “all the phenomena presented by organized beings, their extinction & succession in past ages, & all the extraordinary modifications of form, instinct, and habits which they exhibit” are accountable to that nameless “general principle in nature.”
A big claim. The cover letter was more modest. Here's a hypothesis I've hit upon to explain the origin of species, Wallace said. He hoped it might seem as new to Mr. Darwin as it had to him when the notion first struck.
It didn't.
27
The manuscript was datelined: “Ternate, February 1858.” Wallace had mailed it from a tiny volcanic island in the northern Moluccas. As the story goes, he got his inspiration during an attack of malarial fever, while forced to lie bedridden suffering alternate cold and hot fits and unable to do anything but think. One thing he thought about, as he'd been doing for years, was how species come into existence. Having seen such a spectrum of variation in the wild, having charted the suspicious distribution of closely allied species, Wallace had become ever more persuaded of the reality of transmutation. But what was the causal mechanism? During his bout of fever, he happened to remember Malthus, whom he'd read more than a dozen years earlier. He recalled the geometric rates of population increase, the slower increases in available food, the consequent “checks” to human population growth. Suddenly it occurred to Wallace, just as it had to Darwin, that such checks also regulate animal populations in the wild. Pondering all that adversity and mortality, he asked himself why some individuals survive while so many others die. “And the answer,” as he recollected long afterward, was that “on the whole the best fitted live.” Accidental variation plus the imperatives of struggle result in differential survival; differential survival leads to adaptation; divergent adaptation over vast stretches of time leads to fleet antelopes, strong-winged pigeons, and tall giraffes. Bingo. “The more I thought over it the more I became convinced that I had at length found the long-sought-for law of nature that solved the problem of the origin of species.”
When the fever broke, he got up and scribbled some notes. Within a few days he had written his manuscript and sent it to Darwin by the mail steamer that stopped at Ternate.
Why had Wallace chosen Charles Darwin, of all people, to receive an outpouring of his febrile idea? It wasn't because Wallace recognized Darwin as a fellow transmutationist. The older man, in his published writings and their few exchanged letters, had been too coy to give that much away. As far as Wallace knew, Mr. Darwin was merely a conscientious naturalist of the traditional sort, whose interests ran to biogeography, barnacles, and variation in poultry. But Wallace, thrilled with what he'd hit upon, eager to announce it, had to send the manuscript to
somebody
, and his options were limited. He'd already heard through Samuel Stevens of the derogatory mutters, in London, about his ventures into theory. The old boys at home thought he should stick to gathering salable beetles. He might well have ignored those dour signals and mailed his paper to Stevens anyway, for forwarding to the
Annals,
as he'd done with the earlier writings. But that didn't seem wise, not this time; the stakes were too large, the concept too incendiary. Or maybe he was simply aiming higher. Who else did he know? Wallace was isolated out there in the islands, and not just by miles and water. His lack of scientific credentials, educational polish, and social position left him feeling marginal. He had grown discouraged by a sense that his “law” paper came and went quietly, attracting almost no notice. He had even complained about that in a letter to Darwin. Darwin had responded, as a kindly aside, that it wasn't quite soâthat Darwin's friend Lyell, for one, had found the “law” paper intriguing.
Lyell had? Sir Charles Lyell, Britain's preeminent geologist? This was a delicious bit of flattery for Wallace's modest ego. Now, half a year later, Wallace was hoping to play the Lyell connection. If the enclosed manuscript on species seems sufficiently important, he asked Darwin, would you please pass it along to Sir Charles?
28
Darwin felt crushed. He had only himself to blame. His dilatoriness, his perfectionism, his big mouth. Suddenly he was trapped, flattened, between the demands of honor and the claims of self-interest. He howled with pain. “Your words have come true with a vengeance,” he wrote Lyell, “that I shd. be forestalled.” Enclosed is a manuscript that Wallace asks me to send you, said Darwin. It's well worth reading. It's also, he added glumly, the closest thing to a précis of my own theory. (In the panic of the moment, he was overlooking a significant difference: Wallace focused on competition between varieties, not between individualsâthat is, selection of one group versus another, not selection of individuals within a group.) “I never saw a more striking coincidence,” Darwin moaned. Even some of the phrases Wallace used, such as the “struggle for existence,” echoed what Darwin had already written into the draft of his big book. Wallace hadn't asked him to help get the manuscript published, Darwin noted, only to share it with Lyell; but of course Darwin would write Wallace immediately and offer to send it to any journal. “So all my originality, whatever it may amount to,” he whined, “will be smashed.”
Lyell, always a steady head, advised him to calm down. Maybe there was an alternative solution, less drastic than all-or-none priority. Joseph Hooker, also a sensible friend as well as a faithful one, was brought into the discussion. As days passed and letters flew back and forth, though, Darwin's attention became split between the Wallace surprise and some family concerns not conducive to calm.
A wave of sickness hit the village and the household. His eldest surviving daughter, Etty, caught a sore throat that turned out to be diphtheria, a scary and relatively unknown disease in those days, which was running at epidemic levels across Britain. By the time Etty improved, there was another disease to fear: scarlet fever, which had broken out locally. Three children in the village died, others were hovering in danger, and on June 23 it hit baby Charles, the youngest Darwin.
This namesake child is a mysterious figure, about whom evidence is scarce and scholars disagree. Born when Emma was forty-eight, christened Charles Waring Darwin, by the age of nineteen months he was a toddler who hadn't toddled. Small for his age, he didn't walk or talk. He had a sweet, tranquil disposition but seldom laughed, seldom cried, and made weird faces when he was excited. Evidently he had some sort of physical and mental debility, though it's hard to say what. According to Etty's later testimony, her littlest brother was born “without its full share of intelligence.” Of the two best and most thorough Darwin biographies, Janet Browne's and the Desmond-and-Moore, the latter describes baby Charles as “severely retarded,” the former says that he “may have been slightly retarded,” possibly because of mercury poisoning from ill-conceived Victorian medicines. Randal Keynes, Darwin's great-great-grandson, argues persuasively that Charles Waring suffered from Down Syndromeâthat is, physical impairments resulting from an extra copy of the twenty-first chromosome. It was a perplexing condition at the time, not even partly clarified until Dr. John Langdon Down (no connection to Downe village or Down House) identified it eight years later. Whatever his trouble, baby Charles was loved by Darwin and Emma with a pitying tenderness that probably included some sense of burden and regret, making their feelings all the more complicated when he died of his fever on June 28.
The end was ugly and hard, as it had been with Annie. Otherwise that death and this one were almost as different as two child-losses could be. “It was the most blessed relief,” Darwin told Hooker, “to see his poor little innocent face resume its sweet expression in the sleep of death.” Etty later described her parents' reaction more bluntly, recalling that, “after their first sorrow, they could only feel thankful.” Darwin wrote a short, private memoir of Charles Waring, in which he did his best to accentuate the positive, recalling “nice little bubbling noises” the child sometimes made, how “elegant” he looked crawling naked on the floor, his “placid & joyful” disposition.
In the meantime Darwin had heard back from Lyell with some thoughts about how the Wallace dilemma could be handled. What did Darwin have on paper, Lyell wondered, that might testify to his priority of discovery? Well, there was the manuscript essay of 1844, which Hooker had read; also a six-paragraph summary of the theory, which he'd sent last year to the botanist Asa Gray, his trusted correspondent at Harvard. These unpublished but witnessed writings were proof that he'd conceived the whole idea long ago, solitarily, and stolen nothing from Wallace. “I shd. be
extremely
glad
now
to publish a sketch of my general views in about a dozen pages or so,” he told Lyell. “But I cannot persuade myself that I can do so honourably.” He worried that receiving the Wallace manuscriptâwhich he hadn't asked for, after allâput him in a bind. He would rather burn his own book-in-progress, he said, than be seen as behaving shabbily. But was it too late to publish a summary of his views and say he was doing so on the advice (two years earlier) of Lyell? He repeated: “If I could honourably publishâ¦.” No, he couldn't persuade himself that it was okay; but implicitly he begged Lyell and Hooker to do the persuading.
Altogether, he was fuddled with anguish. He hated himself for thinking about such stuff while his children were battling for their lives. “This is a trumpery letter,” he ended, “influenced by trumpery feelings.” But the feelings wouldn't go away.
Lyell and Hooker took their cue. Within days, serving him faithfully as friends, serving science by their lights, serving justice more dubiously, they cooked up an arrangement that rescued the situationâor at least, it rescued Darwin's interests. They certainly couldn't ignore Wallace's paper entirely and connive to see Darwin given credit alone; that would have been dishonorable, unprofessional, and scandalous when the truth came out. Instead they devised and sponsored a joint presentation of Wallace's manuscript and Darwin's unpublished work. This peculiar duet would occur at the next meeting of the Linnean Society, one of London's better scientific associations, of which Hooker, Lyell, and Darwin were all governing members. Darwin consented to the arrangement, sending Hooker his 1844 essay and the six-paragraph summary he'd written for Gray, along with another disclaimer: “I daresay all is too late. I hardly care about it.” No wonder: The baby at that moment was still alive, but barely, fevering toward a crisis. Wallace, on the other hand, didn't consent to the joint reading (at least, not in advance); he couldn't, because no one consulted him. He was still doing fieldwork in the eastern islands, unreachable on short notice, far out of the loop. Nobody seems to have asked Lyell and Hooker:
Gentlemen, what's the all-fired hurry?
Nobody suggested that Darwin, having waited twenty years to publish, might reasonably wait another six months for Wallace's acquiescence. It was a done deal before anyone thought to quibble. The reason for hurry, I think, was that Lyell, Hooker, and Darwin all felt some embarrassment about this high-handed bestowal of shared credit, and they knew that delay might bring complications.