Whoever has some experience with breeding canaries will know that, if a white Nightingale (a male) is mated to an ordinary Nightingale (a female), there will result no other than Nightingale of ordinary colour in the first year. Next year, however, if one mates a young female of this offspring again with the white male, the white colour will appear in some of their offspring, and in the third year (after mating white with white) no others than white birds will result.
BARON VON PERNAU, Angenehmer Zeit-Vertreib (1716)
Over beer and more cigars, Duncker asked Reich how the various different canary breeds had arisen. Like most fanciers, Reich believed that much of the variation in canary size, shape and song occurred as a result of crossing the original wild bird with other finches, but Duncker wasn’t convinced. After all, Darwin had shown that the entire range of pigeon varieties, infinitely more diverse than the canary, could be traced back to a single ancestor, the wild rock dove Columba livia. Duncker could see no reason why the same shouldn’t be true for the canary.
But mapping out the canary’s family tree and pinpointing the emergence of each breed proved to be more difficult than he anticipated. Canary strains were often much less distinct than pigeon breeds and because they arose only gradually there was never a precise moment when a canary fancier could announce the creation of a new variety.
The process of domestication was Darwin’s model of evolution in nature. The development of different pigeon or canary varieties was equivalent to a single species giving rise, over time, to a number of new ones radiating out to occupy a variety of niches. This is exactly what Darwin imagined had happened on the Galapagos Islands with the ground finches in a process ecologists now call ‘adaptive radiation’. The Galapagos were also where species suddenly seemed less like fixed entities created by God and more like something mutable.
Darwin visited the Galapagos on his Beagle voyage in 1835 and, just as he had done elsewhere, he made collections along with other crew members, including Captain FitzRoy, of the local wildlife. Darwin had little idea that the various small birds they so carefully killed, stuffed and labelled would help to turn the world upside down. Only after he had returned home and was ruminating over his Galapagos experiences did the full significance of these little birds become clear. They differed so much in appearance, especially in the size of their beaks, that Darwin struggled to identify them and he labelled them variously as finches, wrens and gross-beaks. Once he was back in London, he passed his study skins on to John Gould, an up-and-coming ornithologist and artist who, unlike Darwin, recognised immediately that, despite the differences in their beaks, the birds were very closely related. More important, Gould realised that they were unique and comprised an entirely new group of twelve species of ground finch. None the less, when Darwin came to write his Journal of Researches into the Natural History and Geology of the Countries visited during the Voyage of H. M. S. ‘Beagle’ (1839) he was still dithering about whether the finches really were separate species or merely varieties of a single species. As he deliberated, an incident came to mind in which the resident Spaniards on the Galapagos told him that they had only to look at the shell of a giant tortoise to be able to say which of the various islands it came from. The tortoises and finches had more in common than Darwin thought. Each group of species had originated from a single mainland ancestor and after arriving on the Galapagos aeons earlier eventually spread to the separate islands where the different environmental conditions caused them to diversify.1
Now imagine a rerun of the Galapagos finch saga in sixteenth-century Europe. In this scenario the finch ancestor resides in Germany, having been brought there from its native Canary Islands a few centuries earlier. The German breeders ‘improved’ the wild canary in captivity by artificially selecting birds on the basis of their song. Unwittingly, though, they also did two other things. First and rather obviously, they selected canaries for their ability to reproduce in captivity. Second, by repeatedly breeding those few individuals that accepted captivity, they released some of the heritable variation that had previously lain unexpressed in the wild canary’s genes. In focusing their artificial selection efforts entirely on the birds’ song, the Germans, initially at least, ignored the occasional white feather or clear yellow cap. Over time, more and more variations in colour, size and shape appeared through the chance combination of rare genes and some German fanciers decided to perpetuate this variation by deliberately choosing to breed from birds of particular colours – like those illustrated in Lamm’s book. Nonetheless, the market was primarily for singing birds and the quality of the birds’ song remained the main priority.
By the early 1700s when Hervieux wrote his famous monograph, canaries showed quite a lot of variation in colour but there were few, if any, truly distinct varieties. Once the English got their hands on German birds in the early eighteenth century, however, all that changed. It was equivalent to the first finch ancestor arriving on the Galapagos. The analogy goes even further: the different towns in England – Norwich, Manchester, London – were like the different islands of the Galapagos archipelago. Each one imposed a slightly different selection regime on its canaries, pushing them out along different branches of an evolutionary tree.2
In plotting out the canary’s evolutionary history Duncker struggled to decide which of the early authorities he could trust. So many of those who wrote about canaries cribbed their information from earlier accounts that it was extraordinarily tricky to pinpoint the origin of information, let alone a particular breed. The key period for the canary’s domestic evolution, Duncker soon realised, was the century between about 1720 and 1820. Had Eleazar Albin been a better observer, his Natural History of Birds might have helped, but he merely noted the presence of six types, similar to the six listed by Thomas Hope, whose little book, The Bird Fancier’s Necessary Companion published in 1762,3 included a description of what he calls the ‘Spangled Sort’. This is probably the same as what Albin calls ‘the most beautiful feathered bird’ and what we now recognise as the Lizard, and probably the very first established variety.4 Hope captured the essence of the canary breeders’ mentality, and their obsession with scarcity, when he wrote, ‘Therefore, For the meer uncommonness only of the Thing it is, that the Black Tails, and Cap’d Birds, are most esteemed . . . So that this is nothing but meer fancy, because Birds with White Tails, & no Caps, are so Common.’
Meer fancy. The birds whose particular traits breeders like Hope actively chose to perpetuate were fancy birds; these were the selected lines, the future gene stock of particular breeds. The rest were ‘common or gay’ birds – mongrel canaries, whose carefree breeding included no future vision, no fantasy. A bird-fancier was someone who bred fancy birds; the terms ‘fancy’ and ‘fantasy’ have the same root, reflecting the fact that fanciers focused their efforts on creating something they had in their minds’ eye.
Thomas Hope also reported how ‘Some Canary Birds are longer from Head to tail, are taller, & have blacker Legs than others . . . Of these, The Best Sort, wither for Singing, or Breeding, are the Tallest, and of Near a Span Long, from the Bill, to the end of the Tail . . .’ A span was the distance from the end of the thumb to the end of the little finger, a length of about nine inches. These long, thin canaries, which eventually gave rise to a number of breeds, including the Yorkshire Fancy, had their origins in Flanders and were apparently brought to England by French Protestants known as the Huguenots.
The Huguenots had a marked effect on English culture including, legend has it, its bird-keeping culture. Between the sixteenth and eighteenth centuries huge numbers of Huguenot refugees fled from the Continent to England to escape persecution by their Catholic countrymen. The oppression began in France when the first Huguenot was burnt at the stake in 1523, and once it started the ethnic cleansing was relentless. When Louis XIV legalised massacre through the Edict of Nantes in 1685, 250,000 Protestants promptly fled to England, Holland and North America. Recognising the contribution that skilled Flemish and French craftsmen could make to the country’s economy, England’s Protestant rulers welcomed them. Of course, the asylum seekers were opposed by local artisans who felt threatened by this influx of foreign talent, but the refugees richly repaid England for its hospitality, improving virtually every manufacturing trade, including the making of paper, glass, cloth as well as carpentry, hat-making and horticulture.
The most successful of the Huguenot immigrants were cloth makers, especially silk and wool weavers, who settled in the city of Norwich, and further north in Yorkshire and Lancashire, bringing their birds with them. Weaving was a cottage industry and working at home was entirely compatible with canary keeping. The birds’ song kept the weavers entertained as they worked, just as the radio does in today’s factories. The birds’ breeding output provided some supplementary, untaxed income; and the quality of their birds became a point of competition for men when they were not at work.
Some of the opposition the English felt towards these immigrant workers – strangers, sharpers and intruders, Hoghen-Moghens, ‘Hugunots’ and shoemakers – was expressed in an anonymous political poem published around 1708, which starts:
CANARY BIRDS NATURALISED IN UTOPIA
A Canto
In our unhappy days of Yore,
When foreign Birds, from German Shore,
Came flocking to Utopia’s Coast,
And o’er the Country rul’d the Roast:-
Of our good people did two-thirds
So much admire Canary birds
For outward Show, or finer Feathers
Far more regarded than all others.
We bought ’em dear and fed ’em well,
Till they began for to rebel.
Duncker was amazed by this poem, which he found quoted in Davenport’s messy paper, but he was uncertain whether it genuinely documented the importation of canaries into Britain or whether these particular canaries merely symbolised the unwelcome Huguenots.
As canary keeping grew more popular in the late 1700s informal societies began to emerge, providing an opportunity for men to socialise, exchange ideas and use their birds in competitions. These local federations, which met in coffee houses and taverns, forced common standards on what was expected of canaries because this was the only way to compete.5 Transport was poor and human communities were still extremely insular, with pronounced regional differences in dialects and customs. It was precisely this combination of isolation and local tradition that resulted in the evolution of different canary breeds. Cities were effectively islands, each with its own environment in which close-knit groups of breeders expressed their fancy about what they felt was desirable in a canary. Just as with natural selection, the course of canary artificial selection was dictated by what was available. And what was available in England was strongly influenced by the Huguenot émigrés, who favoured the very large, upright canaries sometimes referred to as Old Dutch – more than twice as large as the original little wild bird. These big-bodied birds provided much of the raw material for the English breeders, whose strong regional preferences rapidly gave rise to different breeds. The industrial cotton towns of north-west England considered size crucial and developed a giant of a canary – the Lancashire. Just over the Pennines to the east, breeders strove to produce a very tall, upright bird, the Yorkshire canary, which to win prizes had to be slim enough – so they said – to pass through a wedding ring. In East Anglia a richly coloured, almost orange John Bull of a bird was preferred – the Norwich canary. In the Low Countries posture was deemed important, resulting in the hunchback Belgium Fancy. It was later appropriated by the Scots who produced a bird with an academic stoop, known as the Glasgow Don. In France birds with long frilly feathers were favoured.
All these variations in size, stature and feather quality completely bypassed the Germans who, with a nationalist fervour that would persist unabated for centuries, continued to ignore the canary’s appearance in favour of its voice.
The major thrust of selective breeding among the English canary breeders at the start of the eighteenth century occurred as men were ‘improving’ all sorts of animals through artificial selection. People described themselves as dog fanciers, pigeon-fanciers and chicken fanciers, but not, as far as I am aware, as sheep or pig fanciers. Nonetheless, selective breeding among farm animals was all the rage. Stockbreeders dressed up their activity as a patriotic response to a national need for bigger, faster-growing beasts to provide more meat for a burgeoning human population, but in reality they were no different from canary breeders in being driven by status. In one important respect, however, they did differ: livestock breeders who could indulge in experimental breeding were, without exception, very rich landowners with both the time and resources to breed bigger and better animals. Their wealth allowed them to work with huge numbers of animals, on a scale unimagined by most canary breeders, enabling them to make very rapid progress. Some of them were also very skilled. The stock-breeder Sir John Sebright boasted that he could produce pigeons of any type of feather in three years and any body form in six.
One might also think that there was a commercial incentive for livestock breeders but, paradoxically, ordinary farmers were extremely wary about adopting the new breeds of cattle, sheep and pigs. If wealthy breeders had gone to all this trouble to produce giant meat-making machines, why were farmers reluctant to take advantage of them? The cattle breeders’ obsession with their own prestige drove them to produce beasts so extreme in size and shape that they were almost useless to ordinary farmers. The livestock breeders’ self-indulgent endeavours resulted in huge-bodied, tiny-brained cattle that are only remembered now from their naive portraits.
The eighteenth and nineteenth centuries saw an explosion in the breeding of animal varieties.6 In 1800 there were just fifteen recognised breeds of dog, but a century of artificial selection created no fewer than sixty varieties. The same occurred with virtually all forms of livestock, including the domestic fowl, the pigeon and the canary. According to the Soho cage maker Thomas Andrewes, when he published A Bird Keeper’s Guide and Companion in 1830, the number of distinct canary varieties had increased from half a dozen to twenty.7 He gave the most popular as the Lizard, Norwich, Yorkshire, Belgian and German, as well as the London Fancy. This breed still has a special place in the hearts and minds of canary breeders, and contemporary illustrations show it to be a beautiful bird; deep orange-yellow with jet-black wings and tail produced by a combination of genes that has since been lost – apparently for ever, since this breed became extinct during World War I.
FIGURE 4 Duncker’s evolutionary tree for canaries, starting with the original wild bird. Notice Reich’s canary positioned at the top left.
When Hans Duncker finally completed his evolutionary tree for canaries (Figure 4) he knew it wasn’t perfect. But given the uncertainties in the material he had at his disposal, it was the best he could do. Had they been alive, Hans Ehlers, his old supervisor, and Ernst Haeckel certainly would have approved, for this exercise would have been close to their hearts and no one since has done better. Nonetheless, Duncker must have wondered why Darwin hadn’t done this for canaries, as he had for pigeons.
Duncker and Reich created this evolutionary tree together and Reich must have been very proud to see his nightingale-canaries on the uppermost branch of the tree. Their superior position was the result of generations of careful selection, as individuals with the best attributes were encouraged to proliferate. We have no idea whether Duncker and Reich ever discussed it, but the parallels with humans, and the German people in particular, were obvious. The similarities stemmed from a particularly persuasive form of social Darwinism that had begun in the 1870s. The famous biologist Ernst Haeckel pointed out that it was the Germans who ‘deviated furthest from the common form of apelike men’ and in whom one finds the ‘symmetry of all parts . . . which we call the type of perfect human beauty’. This sort of thinking was still widespread in the collective mind of the German nation in the 1920s and as later events showed Duncker was enthusiastic about science improving society. We know nothing of Reich’s views, but it would have been surprising indeed if the topic of improving society through careful breeding had not cropped up at some stage in their bird room conversations.8
It was almost inevitable that Hans Duncker would turn next to consider the processes by which the different canary breeds had been produced. How had the early breeders created the different strains? Reich had no idea; all he knew was how fanciers like himself attempted to improve their existing stock. Fanciers made a conscious effort to breed only from the birds whose traits they admired, often pairing close relatives and rejecting individuals that didn’t have the correct attributes. Intrigued, Duncker went back and reread Darwin, who gave him the more scientific answer he was hoping for. In the Origin of Species he said that in their quest for champions, pigeon-fanciers had employed two types of artificial selection. ‘Methodical selection’ – which was what all livestock breeders practised – consisted of breeding individuals together with the explicit goal of developing a particular trait such as body size or establishing an unusual ‘sport’. ‘Unconscious selection’ was more subtle, but to Darwin much more important. It resulted from the cumulative actions of thousands of individual fanciers whose only objective was to breed together their best birds – but with no specific goal in mind. Generation after generation of unconscious selection resulted in changes that were virtually imperceptible in the short term, but dramatic when viewed over a longer period. To his cousin, William Darwin Fox, Darwin wrote, ‘The copious old literature, by which I can trace the gradual changes in the breeds of pigeons has been extraordinarily useful to me.’ The pigeon-fanciers’ unconscious selection was Darwin’s apposite and accessible analogy for natural selection.
In the three years prior to publishing the Origin of Species in 1859, Darwin had become obsessed with pigeons and had set up a loft in the garden at Down House. Encouraged by a friend, the eminent naturalist William Yarrell, he acquired numerous different breeds from a top pigeon-fancier in London. Darwin and his sixteen-year-old daughter Henrietta were enthralled by their new acquisitions and, writing to his cousin, Charles said, ‘They are a decided amusement to me, and a delight to H[enrietta].’ Darwin eventually had as many as ninety pigeons – including tumblers, pouts and barbs – in the Down House garden and it is a measure of how seriously he regarded his pigeons that after discovering Henrietta’s cat had killed some of the birds he got Parslow, the family’s long-standing retainer, to shoot it. Henrietta never forgave her father.9
Darwin was fascinated by all aspects of his charges; he watched their courtship rituals on the lawn and, together with Parslow, he dissected and skeletonised them in the potting shed. He joined two of London’s most prestigious pigeon clubs; the Columbarian and the Philoperisteron. After several evenings of pigeon chat in smoky gin parlours, Darwin confided to his son that most pigeon-fanciers seemed to be funny little men, obsessed with producing and maintaining particular breeds. The ‘almond tumbler’ was their favourite, and despite his cynical comments Darwin was seduced: ‘These are marvellous birds, and the glory and pride of many fanciers.’ No fewer than 150 distinct breeds of domestic pigeon were recognised in the 1850s and although the fanciers themselves couldn’t care less, they assumed each to be a separate species. In contrast, naturalists like Yarrell and Darwin were confident they had all arisen from a single wild ancestor – albeit guided by the grubby hand of man.10
Had Darwin ventured into canary clubs instead of pigeon clubs he would have encountered exactly the same obsessive desire to produce the best birds. Indeed, he would have found the same attitude in any of the numerous animal-breeding societies then in vogue in Victorian England.
In his quest to understand the canary’s evolution, Duncker also consulted The Variation of Animals and Plants under Domestication (1868), Darwin’s more detailed and distinctly turgid follow-up to the Origin of Species. As he turned the pages, he began to realise that generations of canary breeders, just like pigeon-fanciers, had been carefully selecting their birds. The only difference was that they hadn’t been doing it for quite so long. Pigeons have been domesticated for thousands of years – hence the greater number of varieties. Darwin’s concept of methodical selection of sports – selectively breeding from canaries with flecks of yellow plumage, or those that were all white – was the most obvious form of artificial selection and the easiest to come to grips with. Hans Duncker now focused on how this selection might have happened.
Animals with atypical colouring have always fascinated people, and museums are stuffed full of them, deluding schoolchildren into thinking that they are much more common than they really are. I remember as a child visiting my uncle’s and aunt’s farm in Norfolk and being shown a wild blackbird that, instead of being black, was the colour of a golden retriever. People with no other interest in birds came from miles around just to gawp at it. And it was spectacular – in forty-odd years of watching birds I have seen nothing like it since. Albinos or even partial albinos are among the commonest plumage aberrations and blackbirds with white patches are far from unusual in European gardens. Plumage aberrations like these sometimes result from disease. They can also be due to genetic defects induced by radiation.11 It is now common knowledge that X-rays disrupt the genetic instruction manual, but in the 1920s it had only just become clear that radiation caused permanent genetic damage. Duncker had to point this out to his colleague Hans Meyer, director of radiography services for the Bremen hospitals, who was using radium, a potent source of gamma-rays, to treat cervical cancer in women.12 One hopes that Duncker’s warning was heeded, for by carrying the radium around with them in a little tin in their trouser pockets, the gynaecologists irradiated their own vital parts as well as those of their patients.
Mutations also occur by chance, albeit rarely, and their bearers, like the Norfolk golden blackbird, rarely survive long in the wild. But they can be nurtured in captivity and their genetic attributes captured and passed on to others.
Sports were perpetuated by breeding them back to their mother or father: a monumentally important trick technically known as a back-cross.13 Most professional animal breeders I spoke to about this assumed that the back-cross was first used after the rediscovery of Mendel’s work, but in fact plant breeders were using it in the 1750s and animal breeders even earlier. English racehorse breeders developed the technique in the late seventeenth century – through necessity. At that time they were importing Arab stallions, but not Arab mares, and had little choice but to mate their glamorous studs with less than glamorous home-grown mares. They then mated their cross-bred female offspring back to the original stallion, ‘grading-up’ generation after generation in a sequence of back-crosses designed deliberately to increase the proportion of Arab blood. By the early 1700s well-informed farmers were using the same technique to capture traits in sheep and cattle, and it is hardly surprising that grading-up was well known among administrators like Baron von Pernau, who in 1700 described the same method to produce a strain of white nightingales. Extraordinarily prescient in all his bird observations, Pernau also makes it crystal clear that the back-cross technique was well known to canary breeders at that time, indicating that this was precisely how they ensnared those first elusive patches of yellow plumage.
Once several canaries with yellow feathers existed, the change from green to yellow could in principle have proceeded fairly rapidly. However, back-crossing mothers with sons, or fathers with daughters, is the most severe form of inbreeding possible and inbreeding was a very mixed blessing. On the one hand it allowed breeders to capture traits very easily and even appeared spontaneously to create ‘sports’. But inbred individuals were much more prone to disease and birth defects. Pairing closely related birds together resulted in more infertile or unhatched eggs, more hatching failures and more premature deaths. There seems little doubt that the canaries being bred in Germany in the 1500s and 1600s were subject to high levels of inbreeding, not least because, as all animal breeders know, some couples are more productive than others and there is often little choice but to continue to breed from these individuals.
Fanciers gradually began to realise that breeding in and in – what they also called consanguineous mating, literally the ‘same blood’ – was reducing the reproductive success of their stock. They also recognised that such problems could easily be rectified by out-breeding, that is by introducing new blood. But outbreeding was a dangerous game too because at one fell swoop it diluted, or at worst eliminated, all those traits the breeder had so carefully cultivated. A compromise was needed and, rather like royal dynasties, bird breeders resorted to something called line-breeding. They banned brother-sister marriages but encouraged matings between cousins to retain accumulated genetic or monetary wealth within families and used the occasional infusion of new blood to avoid the worst excesses of inbreeding, much as Anne of Bavaria was imported from abroad to inject new life into the French royal stock.
But sometimes even matings between cousins, like that of Darwin and his wife Emma, were too close, as Darwin began to realise, watching his brood of sickly children grow up. Illness and death permeated the Darwin household and in June 1850 Darwin’s eldest daughter, nine-year-old Annie – his favourite – became sick with an illness that would not go away.14 Her parents tried everything, starting with conventional medicine, such as it was, but when that failed they tried the new idea of sea bathing. And when that too failed they sent her to Dr Gully’s hydrotherapy establishment for the water cure – wet towels and cold compresses – which Charles had found so helpful with his own illness. But the water cure didn’t work either and her desperate parents now resorted to folk medicine – a caged bird. Throughout Europe it was widely believed that small birds could cure a sick child by absorbing its sickness, and red birds like the crossbill, robin and bullfinch were thought to be the best – especially for scarlet fever – for the doctrine of signatures, common among herbal remedies, applied to birds too.15 The link between redness and fever was obvious but, in fact, almost any kind of small bird would do and in October 1850 Charles and Emma bought Annie a yellow canary. She was enchanted by it. But as she herself recorded, within a few months the bird sickened and died. And by June the next year Annie too was dead – of consumption. Her parents were devastated and the pain of her passing lingered unabated for years. The canary had failed, just as it had done for Dickens’s Little Nell ten years earlier.16 When Darwin came to write his book on Variation seventeen years later, his memories of Annie were still raw and he could barely bring himself to confront the canary, glossing over it in a single page and making no effort to reconstruct its history as he had for pigeons. In fact, it was worse than this. Darwin, normally so meticulous, got his canaries muddled up and, in his haste to be done with them, referred to a feather-footed variety. There are feather-footed fowl and feathered-footed pigeons, but no such canary.17 The canary, it seems, was Darwin’s bête noire.
At the time of Annie Darwin’s death the canary was just beginning its meteoric rise in popularity. Between the time Mendel died, in 1884, and the recognition of his ground-breaking work in 1900, canaries were well and truly in vogue across Europe and North America.18 It wasn’t surprising that many biologists used them as model organisms to test Mendel’s ideas. Canaries were ideal research animals. They occurred in various forms: yellow and green plumage, crested or uncrested. They were prolific with a relatively short generation time and, thanks to the long tradition of canary husbandry, were very easy to rear.
It was these breeding experiments on canaries and other organisms that Duncker now focused his attention on. Most of these studies had been conducted in the previous twenty years and they encapsulated almost the entire development of genetics as a discipline. They also allowed Duncker to witness the controversies and excitement, the dirty dealing and euphoria as genetics struggled to emerge as a new discipline at the forefront of biology.
Mendel’s findings had been simultaneously and independently rediscovered by three botanists in the course of their own studies of inheritance: Hugo de Vries in the Netherlands, Carl Correns in Bavaria and Erich von Tschermak in Austria.19 But it was the Cambridge zoologist William Bateson who made it his life’s goal to promote Mendel’s work. Bateson read Mendel’s paper on his way to give a lecture in London on 8 May 1900 and was sufficiently inspired by it to rewrite his talk on the train, and spent the rest of his life expounding Mendel’s ideas. Bateson was a Yorkshireman, born in the old whaling town of Whitby and educated at Rugby, where he was described as a ‘vague and aimless boy’, and at Cambridge where he was thought arrogant and untidy. A colleague once said of him, ‘William wasn’t a person you were fond of, you admired him.’20 Inspired by de Vries’s work, Bateson had Mendel’s paper translated and in 1902 published it together with his own Mendel’s Principles of Heredity: A Defence. The defence was necessary because Mendel’s revolutionary ideas were by no means universally accepted. The opposition consisted of a group of evolutionary biologists headed by Karl Pearson, a brilliant mathematician and statistician. The biometricians, as they were called, were sceptical about Mendel’s results and claimed that Bateson and his followers were uncritical in their acceptance of his ideas. Both groups considered themselves evolutionary biologists and both were inspired by the writings of Francis Galton, but differed fundamentally in outlook.
Galton and Darwin were cousins, and Galton considered the Origin of Species to be among the most inspiring books ever written, but he could not accept the notion that natural selection worked on the tiny, almost imperceptible variations between individuals. Galton preferred the idea that selection operated on major ‘sports’ or discontinuous variation, and that evolution proceeded by discrete leaps. He wasn’t alone; T. H. Huxley, Darwin’s Bulldog and greatest ally, felt much the same. Bateson was convinced that evolution occurred as a result of fairly major shifts in characters and one of his objectives was to show that these shifts occurred in animals as well as plants. To this end he set up breeding experiments with poultry, mice and canaries at his home at Grantchester, near Cambridge, in the early 1900s. His basic goal was the same as Mendel’s: to be able to predict the outcome of breeding together two individuals that differed in some clear-cut way. Bateson’s canary work was carried out by Florence Durham, his middle-aged sister-in-law, whom he employed as a research assistant and who, unlike her shy and self-deprecating sister Beatrice, was a formidable and forthright woman.
The biometricians were Darwinian disciples, believing resolutely in natural selection as a gradual and imperceptible process, and were completely convinced that the tiny differences between individuals were perfectly adequate for its operation. They described their opponents’ views as ‘evolution by jerks’. The biometricians’ approach was one of careful measurement and statistical analysis, seeking correlations such as that between the height of fathers and sons as evidence for heredity. Karl Pearson had stepped gingerly and somewhat paradoxically into the shoes of Francis Galton to become Professor of Eugenics at University College London in 1911. His brilliant collaborator was Walter Frank Raphael Weldon (known to his friends as Raphael), who later showed that the results Mendel got with his peas were almost too good to be true. It wasn’t peas, however, but a nondescript little daisy that drove the first wedge between Bateson and the biometricians.
It started on 28 February 1895, when the botanist William Thistleton-Dyer displayed two varieties of a flower called Cineraria at a meeting of the Royal Society in London. One was the wild type C. cruenta from the Canary Islands, and the other a cultivated variety from the botanical gardens at Kew. The two forms differed dramatically in the shape and colour of their flowers, but Thistleton-Dyer’s point was that the cultivated form had arisen from the wild type as a result of artificial selection ‘by the gradual accumulation of small variations’. Bateson wasn’t at the meeting, but saw this as a chance to challenge the prevailing Darwinian view of evolution. He dashed off a letter to the premier scientific journal Nature, claiming that since the cultivated plant was a hybrid of several different species, their original offspring would have been extremely variable and it was from some of these ‘sports’ that the cultivated form had been derived. Thistleton-Dyer rejected the hybrid idea, but Bateson wouldn’t back down and a bitter controversy flourished in a stream of letters published over the next two months. It was at this point that Raphael Weldon stepped in to support Thistleton-Dyer, pointing out that Bateson had not been entirely honest: ‘. . . and that the documents relied upon by Mr Bateson do not demonstrate the correctness of his views; and that his emphatic statements are simply a want of care in consulting and quoting the authorities referred to’.
Bateson was incensed and took it as a personal attack. Nonetheless, like true gentlemen, he and Weldon agreed to meet on 21 May to thrash out their differences. The meeting was disastrous and the two men never spoke another civil word to each other.21 The rift between Bateson and the biometricians grew wider with every new publication by the two sides, and wider still with the rediscovery of Mendel’s work. Pearson and his colleagues criticised their opponents for seeing Mendelian ratios wherever they looked and for failing to consider any alternative explanations, and accused the Mendelians of ignoring results that were inconsistent with their views. For their part, the Mendelians scoffed at their opponents’ use of correlations and other esoteric mathematical jiggery-pokery to decide whether traits were heritable or not.
The battle moved beyond England’s shores to America, where Charles Davenport vigorously waved the Mendelian flag. A traditional zoologist, Davenport began his career studying the development of embryos, an interest that culminated in the publication of the encyclopaedic and much-fêted two-volume Experimental Morphology in the 1890s. Soon after, he switched to study variation and evolution, employing – at least for the time being – Karl Pearson’s new statistical methods to analyse his results. Then, in 1902, after reading Bateson’s translation of Mendel’s famous paper, he underwent a conversion and became an ardent apostle of Mendel, proposing that the newly formed Carnegie Institute of Washington spend $10 million to establish a ‘Station for Experimental Evolution’ at Cold Spring Harbor, New York, with himself at its head. Two years later this dream had become a reality and Davenport, like Bateson in England, began exploring the inheritance of eye and hair colour in humans, and plumage traits in chickens and canaries. He was phenomenally productive and published over 400 articles – an extraordinary output even by today’s highly competitive standards and something few scientists ever achieve.22 But output on this scale rarely occurs without cutting at least a few corners.
In 1904 Davenport started to breed canaries to establish the patterns of inheritance in a semi-domesticated species. Earlier studies of heredity had been criticised for using species like chickens, which had been domesticated for thousands of years, and which some said were inappropriate models for the study of inheritance in nature. The aim of Davenport’s canary study was to address the questions: ‘How is the crest . . . [and] . . . the plumage colour inherited?’23 The investigation was based on an original stock of ‘four yellow canary hens (one crested) of the short or German (Harz Mountain) type and two green birds of the same type. Also three yellow cocks (one crested) and two greens (one crested)’ obtained from a New York dealer. Three years later Davenport was able to write, ‘The interpretation of the results of breeding plumage colour is not difficult and may easily be brought to accord with Mendel’s law.’ His results with crests were rather less clear-cut, but Davenport nonetheless concluded that they behaved ‘in a Mendelian fashion’. Even in a species that had been domesticated for as few generations as a canary, Mendel’s rules still applied. Davenport also used his results to show that the ‘yellow canary is derived from the original “green” canary by the loss of black’ and rounded off his paper by writing, ‘The plumage of a yellow canary may be compared with a letter that has been written with invisible ink. Wherever the developer acts (i.e., the black pigment of the green canary is added) that which is written appears with all of its idiosyncrasies.’ When Davenport published these results in 1908, William Bateson immediately included them in his book, Mendel’s Principles of Heredity, delighted to have more Mendelian ammunition.
Davenport’s paper also caught the eye of a celebrated Scottish ophthalmologist and enthusiastic amateur canary breeder, Dr Rudolf Galloway. Unlike Bateson, Galloway was distinctly unimpressed and intensely irritated by Davenport’s results. Indeed, they were catalytic in rousing this normally mild-mannered Scot to angry indignation, stimulating him to sort and analyse his own canary-breeding records accumulated over the previous eighteen years, to counter Davenport’s claims.
Galloway was in a strong position to criticise Davenport because he knew more about canary genetics than just about anyone else at the time, and certainly more than Davenport. There was probably another reason why he felt especially confident in these matters. In 1908 he had produced the ultimate bird – a hybrid between a European siskin and a canary which was a clear yellow colour. Of the 526 canary x finch hybrids Galloway had produced during the previous seventeen years, this was the only one of its kind: the bird breeder’s El Dorado. It was the most highly rated exhibit at the major Scottish shows in 1908 and the following year it was awarded first prize at the national bird show at the Crystal Palace in London.
In a block-buster article in Biometrika, a journal edited by none other than Karl Pearson, Galloway presented the results from his own canary studies,24 summarily dismissing Davenport for not properly defining his terms, for not even knowing what breed of canaries he had used and, most of all, for being a sloppy experimentalist.
Davenport couldn’t bear criticism and immediately drafted a rebuttal. The language of his letter was civil, but one can almost feel him composing it through gritted teeth. His anger, as we shall see, was fuelled by more than a twinge of guilt. Apart from a single reference to Galloway being ‘scientifically untrained’, Davenport’s response is a model of self-restraint and ends on a conciliatory note, commending Galloway on his valuable results. But his attempt to appease the Scot fell on stony ground and Galloway retaliated in print with a further cutting comment: ‘From the scientific standpoint only, his statements might be more consistent, though in all probability valueless . . . From his false assumptions . . . it is quite impossible for him to arrive at any scientifically correct, or practically useful conclusion.’ One could hardly imagine a more devastating denial of Davenport’s work, but immediately following Galloway’s two articles in Biometrika there came another, much worse, this time from a David Heron.
Whereas Galloway had used the subtlety and precision of a surgeon’s scalpel to expose Davenport’s errors, Heron went in wielding a double-headed axe. Davenport must have known he had done a sloppy job, hence the rage, the guilt and the pathetic attempt to appease Galloway. Scientists can be cruel in their criticism of careless colleagues and scientists who do poor research lay themselves wide open for vicious scrutiny and opprobrium. Davenport’s original twenty-one-page article provided Heron with virtually limitless evidence of incompetence but, perhaps for effect, Heron confined his comments to just 114 lines of text and four tables regarding the inheritance of crests. In this small part alone he identified no fewer than 109 errors. The same individual birds, for example, appear in one table as crested and in another as lacking a crest. Experiments were incorrectly labelled and Davenport ignored results that contradicted his Mendelian expectations, and he drew false conclusions from others. ‘It can thus be shown . . .’ wrote Heron, absolutely incredulous at the scale of sheer ineptitude he had discovered, ‘that every conclusion made by Davenport can be proved to be false from a study of his own material; that if a fact has to be stated twice the one statement is flatly opposed to the other and that blunder is heaped on blunder until patience is exhausted. Yet such work is accepted as showing that Mendelian rules apply to Canaries!’ – by which he meant the inclusion of Davenport’s results in Bateson’s book. Few scientists ever receive a public flogging like this and it demonstrates the strength of feeling and the desperate quest for supremacy that motivated the warring tribes.
Who was this David Heron who so savagely attacked Charles Davenport? None other than Pearson’s research assistant. Heron’s hatchet job on Davenport was merely Pearson’s way of opportunistically reprimanding a turncoat and part of his ongoing campaign to discredit the Mendelians.25
When Duncker began his own genetical studies in the early 1920s the dispute between the Mendelians and biometricians had been resolved. If they hadn’t all been so bloody-minded they would have realised much earlier that there was no real disparity in the two visions of evolution. For fifteen years both sides had failed to see that their different approaches were little more than the complementary processes of ‘methodical selection’ and ‘unconscious selection’ that Darwin had highlighted fifty years previously. The crux of the issue was that some traits, like human blood groups and the characters that Mendel had chosen so carefully in his peas, were discontinuous – one thing or the other: A or B, smooth or wrinkled, green or yellow – and controlled by single genes. Other traits, meanwhile, such as human stature, varied continuously and were, crucially, controlled by multiple genes. Regardless of whether the traits were discontinuous or continuous, Mendel’s rules still applied – albeit in more subtle ways than the early geneticists ever imagined.
The papers by Davenport, Galloway and Heron played a crucial role in Duncker’s personal development as a geneticist and he cited their results in his own huge account on canary variegation. Making sense of Davenport’s paper wasn’t easy and, like Heron, Duncker had to go through it with a fine-tooth comb. Clearly much of what Heron and Galloway had said about Davenport was true, but fortunately, amidst the mess of errors, Davenport had included all his breeding results in a table of raw data, enabling the endlessly patient Duncker to sort fact from fantasy. Davenport finished his study by saying that there might be one or two ‘factors’ – what we now call genes – controlling variegation in canaries, a conclusion that broadly coincided with Duncker’s own, and confirmed that canary colours were inherited in a Mendelian manner.
The fact that Duncker should choose to study heredity and to a large extent succeed is absolutely remarkable. For one thing, he was a middle-aged schoolteacher rather than a practising research biologist. For another, in intellectual terms Duncker was completely on his own. Germany had no tradition or interest in studying the mechanisms of inheritance, and as the great historian of biology Ernst Mayr said of this period, ‘The average German biologists were unquestionably backward in their understanding of genetics.’26 But Duncker was anything but average, either in intellect or ambition, and his work was exceptional in the history of genetics in Germany.
It seems strange that the Germans should have been so backward in the study of inheritance when, in terms of evolution, they were said to be more Darwinian than Darwin himself. This was thanks largely to biologist Ernst Haeckel who, after reading the Origin of Species and having what he felt was a near-religious experience of meeting Darwin at his home in England in 1866, became utterly convinced of the truth of evolution and proceeded to Darwinise Germany through his popular science writings. But Haeckel’s views on the mechanism of evolution – the actual manner in which traits were transmitted from parents to offspring – remained hopelessly Lamarckian and he was preoccupied with ‘improvement’. Haeckel muddied the waters, in more ways than one. It wasn’t that German biologists had no interest in the mechanisms of evolution, they had, and ever since the 1870s had been obsessed with the genetic blueprints that allowed an egg to give rise to a bird, or an acorn to an oak. But they were too preoccupied with animal development and structure to worry about the nuts and bolts of heredity itself. In much the same way, the behavioural ecologists seventy years later studied the evolution of behaviours which they assumed were inherited but without making much effort to check.
If there was little interest in inheritance inside German academia the situation elsewhere couldn’t have been more different. In England, Bateson’s work had generated a tidal wave of studies aimed at elucidating the secrets of inheritance, particularly of traits like coat colour in rodents. In the USA Thomas Hunt Morgan, fascinated by development and mutations, chanced upon a white-eyed mutant among his fruit fly stocks in 1907, luring him irrevocably into a pioneering and revolutionary study of transmission genetics. The next twenty-five years saw Morgan’s fast-breeding fruit flies relinquish their hereditary secrets at an ever increasing rate (and much more quickly than Bateson’s chickens, mice and canaries), providing the foundations for modern genetics.
Despite the dramatic progress elsewhere, there were still no chairs in genetics at German universities in 1921 when Duncker and Reich started their studies. The reason lay partly in Germany’s antiquated and hierarchical academic system in which students and younger researchers dare not challenge their professors’ views; a tradition that disrupted the influx of new genetic knowledge from the United States and Britain. At this time zoology teaching in German universities was done entirely by a professor and one or two assistants. Salaries were poor and professors supplemented their income with the fees from extra teaching, so they naturally chose to teach the large comprehensive courses that brought in the most income. The younger staff, who were most aware of recent developments, taught the smaller, more specialised courses. So genetics either didn’t get taught or, if it did, it played second fiddle to developmental embryology.27 The almost total intellectual isolation in which Duncker worked makes his success all the more remarkable, although perhaps it was precisely because he lived and worked outside the academic system that he achieved so much.
In late 1924, having successfully completed the studies of variegation and confident that he understood the inheritance of canary colours, Duncker adopted an utterly audacious plan. It was an idea that flew in the face of everything he had learned about the single-species origin of domestic breeds. His idea was to combine the genetic material of two distinct species to create a new one – a transgenic canary. This was the first attempt to create a genetically modified animal, the first bit of animal gene technology, and once again Duncker was decades ahead of everyone else. The quest for the red canary had begun.
