Darwin worked mainly with skeletons rather than skins, Cooper says as we climb the stairwell to the next floor. Skeletons, she explains, are just that, but to prepare skins, “You remove their innards, pop out the brains and eyes, and sew them back up.” We reach the annex floor devoted solely to skin storage, where I lose count of the identical narrow aisles made by double rows of off-white cabinets. The fluorescent lights illuminate a cheery yellow floor, yet the vast room has a sepulchral quality. Without hesitating, Cooper glides down one aisle and pulls open a drawer like those used for lateral hanging files.
Inside are a dozen birds lying in their shared metal coffin, each with a tag on a toe as in a morgue. The skins resemble deflated balloons. She reaches for one. “Collected by A. R. Wallace. 1862,” reads the tag. Neat handwriting identifies it as Gallus bankiva from Malacca on the Malaysian peninsula. This is a red jungle fowl variety that the naturalist Alfred Russell Wallace encountered near the southernmost native range of the bird, between Singapore and Kuala Lumpur. Wallace independently came up with the theory of evolution while traveling in Southeast Asia, and his writings on the subject were read together with Darwin’s at a London meeting in 1858.
In the drawer below are two stuffed red jungle fowl, fresh enough that they seem ready after a century to make a break for the forest. There are dull gray-brown hens and showy roosters lying on their backs, beaks pointed to heaven. The colors of the males in the monochrome surroundings are dazzling. There is a shower of gold around the neck, a magnificent patchwork of royal blue across the body, feathers with a subtle burnt orange brightening to yellow and violet turning to black at the tail. In another drawer, a 1939 specimen is labeled as “Domestic Guinea Fowl x Domestic Fowl.” Another contains hefty chickens with naked necks. A sign on the outside of the drawer explains that they are a breed “periodically featured, incorrectly, in the media as a hybrid between chicken and turkey.” Sometimes species are just species.
The Reverend Edmund Saul Dixon and Darwin inhabited eerily parallel worlds before their correspondence began as The Fancy gathered steam in 1848. Both men were on the verge of turning forty and had graduated seventeen years earlier from Christ’s College at Cambridge University. And both men had contemplated a rural ministry as a way to pursue their intense interest in the natural world.
What set Darwin on a different path, aside from his family’s wealth, was a surprise invitation to go on an around-the-world trip as interesting company for the captain of the Beagle. Shortly after Darwin set sail on what became his famous five-year voyage, Dixon was ordained. While Darwin roamed Patagonia and gathered his Galapàgos finches, Dixon married and moved to a quiet rural parish a hundred miles east of the capital in a modest house with a small backyard and bought a few chickens on a whim. Darwin returned to England to settle with his own wife on an estate in the rolling Kent countryside south of London in September 1842, the same month that Captain Belcher bestowed his gift on Queen Victoria.
Dixon was puzzled by the contradictory advice in the few books on poultry rearing available at the time, and, after observing their behavior and breeding habits, became convinced that chickens “afford the best possible subjects for observing the transmission or interruption of hereditary forms and instincts.” When his wife suddenly died, the widower embarked on an obsessive study of poultry and began to attract attention in the small world of naturalists for his expertise.
In 1844, an anonymous author in Britain published Vestiges of the Natural History of Creation, a slim volume that argued that everything, from planets to plants, developed from earlier forms, which its writer envisioned as an “organic process.” Species evolve. It became a bestseller. Prince Albert read it to Queen Victoria, perhaps in their aviary retreat. But it also drew critics, like Dixon, who argued that the science was flawed and the conclusion blasphemous. He embarked on a series of experiments to demonstrate that different species could not produce fertile chicks, and therefore that species cannot change.
In a gossipy letter to his botanist friend J. D. Hooker in October 1848, Darwin related that their geologist acquaintance Charles Lyell had been knighted by Victoria and spent time at the queen’s new Scottish lair of Balmoral. He also went on at length about his barnacle research. “Though I have done little about species,” he mentioned in passing, “I have struck up a cordial correspondence with a first-rate man.” He had asked Dixon if he would examine newly hatched chicks to see if they showed the same characteristics found in adult birds. Dixon, delighted to assist the esteemed scientist, readily agreed and encouraged Darwin to set aside barnacles and put more emphasis on poultry research.
Two months later, Dixon sent his newly completed poultry book to Down House with a personal inscription. A copy also went to another notable acquaintance, Charles Dickens. It was the end of a year of revolutions that had begun with a bang but ended with a whimper. Monarchies tottered, barricades went up, and Marx and Engels published The Communist Manifesto. Though it was unlikely to bring partisans into the street, Dixon’s Ornamental and Domestic Poultry: Their History and Management was the English rector’s own manifesto, published the same month that the Birmingham show—where he was a judge—set The Fancy into high gear.
On Christmas Day, as Victoria and Albert entertained around a decorated evergreen tree in Windsor, starting another trend, Darwin noted in his diary that he had finished a book on Siberia that was “dull” and another on natural history museums that he found “inclusive.” He also mentioned reading Dixon’s lengthy volume but withheld comment. A detailed compendium of poultry varieties, the book gave specific instructions on caring for and feeding the birds. It also was a forceful and erudite rejection of what the author called “the wild theory . . . so fashionable of late, that our tame breeds or varieties, are the result of cross breeding between undomesticated animals.” Dixon lambasted the idea that species could change, based on his experiments with separate species like chickens and guinea fowl, which were, he wrote, incapable of producing fertile progeny. Each species was locked within its own cage of traits that could never be shared with another, and therefore, no new species were possible. Genesis was the beginning and end of creation. Chicken varieties were permanent and ancient, produced by a creative power rather than human intervention.
Dixon even cited his colleague in an attempt to bolster his case. “Mr. Darwin’s discovery, the result of his great industry and experience, that ‘the reproductive system seems far more sensitive to any changes in external conditions, than any other part of the living [system],’ confirms my suspicion,” he wrote. Reproductive systems, in others words, were the least adaptable animal part. Creating hybrids of two species with working reproductive systems was extremely improbable.
Darwin underscored Dixon’s strong views on the immutability of species in the copy the author had sent. On a blank page at the volume’s end, he mused that many domestic breeds might descend from wild birds, “yet I think others cannot probably have come from their crossing.” Then he crossed out his own comment. It wasn’t until the following March that he offered a catty review to a friend. “It is very good & amusing,” he wrote slyly. What amused Darwin was Dixon’s attempt to halt the public discussion of species change.
The two men continued their correspondence, exchanging extensive notes on Dixon’s breeding experiments, though most of it is lost. The Down House naturalist, however, kept his distance, pleading illness. “I now really hope that your recovery may afford me the opportunity & privilege of making your personal acquaintance some time before the Winter arrives,” Dixon wrote that spring. There is no record that the two men, so similar and yet of such different opinions, ever met. But Darwin soon began to consider how both chickens and pigeons might bolster his case for natural selection.
Dixon grew shrill in the years that followed and dismissed the idea of wild animals turning into domesticated beasts as “a sort of harlequin’s sword” that could “convert a clown into a
columbine.” In 1851, he declared that “the Almighty gave to the human race tame creatures to serve and feed it,” adding that a domestic fowl could not have derived from the red jungle fowl. Such a theory was not only wrong from a scientific point of view. It was also “a great heresy.”
Darwin kept quiet publicly, unprepared to make his argument for species change through natural selection, but he groused to his trusted second cousin William Darwin Fox that Dixon “argued stoutly for every variety [of chicken] being an aboriginal creation” while he also “seemed to entirely disregard all the difficulties on the other side.”
In 1855, as The Fancy bubble burst, Darwin set aside his barnacles and turned to collecting and examining poultry. He had a lot to learn, but was no longer in touch with the knowledgeable but acerbic Dixon. “I was so ignorant I did not even know there were 3 [varieties] of Dorking Fowl, nor how do they differ,” he wrote his cousin that February. “It is an evil to me that Mr. Dixon is such an excommunicated wretch.” The sudden influx of new species in Britain and the drop in prices, however, made them more affordable to collect. Fox agreed to raise the birds, primarily pigeons at first, and Darwin put out a call for pigeon and chicken specimens. That August, as Elizabeth Watts’s publication folded, the first red jungle fowl arrived at Down House. Edward Blyth, a magnificently bearded ornithologist, sent “a fine skeleton of the Bengal Jungle-cock” from Calcutta.
Blyth, a brilliant but troubled scientist, had come close to proposing the idea of natural selection himself more than a decade earlier. He publicly defended the views laid out in Vestiges, earning Dixon’s ire and Darwin’s attention and admiration.
After observing all four jungle fowl species during his two decades in Asia, Blyth had definite views on the domestic chicken’s ancestor. Despite Linnaeus’s classification and studies by Bachman and others, the bird’s origin remained an open question that Darwin was eager to answer. Blyth dismissed the Sri Lankan jungle fowl as a candidate. First cataloged in the 1830s by the French naturalist René-Primevère Lesson—who named it Gallus lafayetii after the Marquis de Lafayette, the war hero and virtual son to George Washington—its range was restricted to this island off the southeast coast of India. The gray jungle fowl, named Gallus sonnerati after the French naturalist Pierre Sonnerat, likewise was found only in a relatively small habitat, in the southern portion of India. Its crow differed significantly from that of the barnyard bird.
Since the green jungle fowl found on the Southeast Asian island of Java lacked the single comb, wattles, and neck feathers typical of a barnyard fowl, Blyth excluded that species as a contender, which left the red jungle fowl as the most likely progenitor. This variety, which includes five subspecies, lives within a vast swath of Asia from today’s northern Pakistan to Indonesia’s Java, each centered in a different zone of that enormous area. This adaptable bird, Blyth noted, “absolutely & essentially conforms to the type of the domestic fowl in all its multitudinous varieties, fully as much so as the Mallard does to the domestic drake; or the wild to the tame Turkey!” The resemblance extended to the rooster’s crow, and the red jungle fowl “corresponds feather by feather with many domestic individuals.”
In December 1855, Blyth wrote Darwin from Calcutta with electrifying news about a paper recently published by Alfred Russell Wallace, then living in Borneo. “Wallace has, I think, put the matter well; and according to his theory, the various domestic races of animals have been fairly developed into species,” the ornithologist reported. Darwin professed to be unimpressed with Wallace’s research, but within a few months set to work on his definitive book on natural selection, quickening his pace of collecting and expanding his contacts. While prowling a poultry exhibition in south London, the naturalist ran into the journalist and poultry fancier William Tegetmeier, and implored him for help in purchasing specimens. Tegetmeier became a key contact and collaborator.
Darwin cast a global net. He importuned a missionary to provide information “in regard to the domesticated poultry and animals of East Africa.” In March 1856 he asked his former servant and assistant, who had moved to Australia, to report on “any odd breeds of poultry, or pigeons, or ducks, imported from China, or Indian, or Pacific islands” and send the skins. He dug into chicken history at the British Museum and had a centuries-old Chinese encyclopedia entry on chickens translated to provide clues to the bird’s origin. “This morning I have been carefully examining a splendid Cochin Cock sent,” he wrote the cousin Fox on March 15 from Down House. “I find several important differences in number of feathers . . . making me suspect quite a distinct species.”
His appetite for poultry was enormous. That fall, live chickens arrived from the interior of Sierra Leone, since he feared that coastal birds were not indigenous to Africa. “By the way,” he wrote one supplier, “I should be very glad of a Malay Cock, if you can ever get one dead for me.” Other live birds and skeletons, including “1 Cock of doubtful origin ticketed Rangoon,” began to arrive at the door of Down House. One can only wonder what the postman thought of these strange deliveries. “I expect soon,” he mentioned in one letter, “to receive Persian fowls.” The shipping, he complained, was costing him a fortune. Post for the Persian birds alone ran to what would now be about five hundred dollars.
By November, Darwin told Tegetmeier that “I really now think I shall have materials to judge the Poultry of the World” in order “to know what amount of difference there is in the Fowls of different parts of [the] world.” To try to determine to his own satisfaction the species that was the chicken’s progenitor, he began to crossbreed birds to see if Blyth was right in the assertion that the red jungle fowl was the original source. By isolating traits common to domesticated chickens and specific jungle fowl, he would confirm the bird’s origin and silence critics like Dixon.
On the Origin of Species, published in 1859, barely mentions chickens, though Darwin gives Blyth credit for the theory that all breeds originated with the red jungle fowl. He put off an extended discussion of artificial selection—that is, domestication—until nearly a decade later. The Variation of Animals and Plants under Domestication is less well known than the famous Origins, but it lays out Darwin’s radical vision of how humans and nature collaborate, sometimes in harmony, sometimes uneasily, and sometimes by accident, to make and remake plants and animals. Humans could not create life from scratch, but they could alter a species by substituting a different climate and soil, giving it food and shelter, and making choices—both conscious and unconscious—about how and when and with whom it would breed.
Darwin tackles the perplexing question of how chickens could have such outrageous variations and still be descended from the same ancestor. Since ancient times, breeders have known how to select the best birds in order to improve their stocks. Fashions came and went in animals as well as clothes. Love of novelty led some Britons to develop “rumpless” fowls lacking a final vertebra, while Indians bred for a frizzled feather look. Some of the novelties would be prized and carefully preserved. Ancient Romans, for example, liked their chickens with an extra toe and white ear lobes that persist to this day. Such breeding didn’t require written records or fancy poultry experts. In the Philippines, Darwin notes, “no less than nine sub-varieties of the gamecock are kept and named, so that they must be separately bred.”
Human control is limited, and enthusiasts like Dixon had overlooked unconscious or unmethodical selection. Birds escape their coops and mate while farmers are asleep. This takes place even in the best-controlled research facilities. And natural selection, the spinning of the genetic dials, can alter how a creature looks and behaves, a process that continues to function even in the barnyard. The occasional bird will be born with what Darwin calls “abnormal and hereditary peculiarities.” Humans might make the most of that new trait, spinning off yet another variety of fowl, or they might decide to not let that characteristic propagate. Darwin summarizes that “there is no insuperable difficulty, to the be
st of my judgment, in believing that all the breeds have descended from some one parent-source.”
The Gallus gallus bankiva, the subspecies of red jungle fowl that Wallace collected in Malacca, is the best candidate for the ancient chicken’s ancestor, Darwin concludes. The domesticated birds that most nearly resemble this wild fowl, he notes, are the gamecocks of Malaya and Java, which are close in size, color, and skeletal structure and even in their crow to the local red jungle fowl. People in the region keep wild cocks to fight their domesticated ones, and the bird may have been first domesticated in Malaya and exported to India. Chinese texts consulted by the naturalist in the British Library support this idea, since they hint at a Southeastern Asian origin for the domesticated bird. Darwin not only pinpoints the ultimate ancestor of the chicken, he also names the region where humans likely domesticated the wild creature. He ruefully acknowledges, however, that “sufficient materials do not exist” to reveal the complete history of the bird.
Just as Dixon used Darwin’s data to argue that species don’t change, Darwin used Dixon’s data to show the opposite. The rector’s experiments demonstrated that crossbreeding other jungle fowl with the red led to infertile progeny. In a later and larger experiment involving five hundred eggs made by crossing gray and red jungle fowl at London’s Zoo, the handful that were raised proved sterile, but the red could cross with domesticated chickens and produce fertile birds. “Hence it may be safely ranked as the parent of this, the most typical domesticated breed,” Darwin concluded.
Why Did the Chicken Cross the World? Page 16
