Katrina van Grouw on the 150th Anniversary of Darwin’s Classic Work

“My work is now nearly finished; but it will take me two or three more years to complete it, and as my health is far from strong I have been urged to publish this Abstract. I have more especially been induced to do this, as Mr Wallace…has arrived at almost exactly the same general conclusions that I have on the origin of species…No one can feel more sensible than I do of the necessity of hereafter publishing in detail all the facts, with references, on which my conclusions have been grounded; and I hope in a future work to do this.”

Darwin bust

A plaster bust of Charles Darwin (a wedding present from a friend) in situ on our living room bookcase—a daily reminder of the man, and his theory, that is the cornerstone of this book.

 The ‘Abstract’ Charles Darwin was referring to here is ‘On the Origin of Species by Means of Natural Selection,’ without a doubt one of the most influential books in human history. Despite being based on over 20 years of painstaking research, it was nevertheless —for the reasons given—written in a hurry, leaving several important questions unanswered. The most significant of these, and the premise on which Darwin’s theory of evolution by natural selection rested, was the question of how qualities can be passed from one generation to the next, and it was this question he set out to answer in the future work he alluded to in the passage above. The book was to be The Variation of Animal & Plants under Domestication and it was published on this day, January 30th, 150 years ago.

It wasn’t, I’m sorry to say, his greatest achievement. Apart from being overly long and lacking the focus and eloquence of Origin it presented a mechanism for inheritance that Darwin knew deep down to be flawed. He called it pangenesis. Every cell, Darwin alleged, produces minute particles called gemmules that circulate around the body and can be modified by circumstances experienced throughout life, eventually congregating in the reproductive organs prior to being passed on to future offspring. We now know, of course, that it’s not gemmules but genes that carry inherited information, and that because the genetic information in the sex cells—the cells that produce eggs and sperm—are isolated from the body cells, characteristics acquired during the life of an individual can’t affect them; at least not in any meaningful, long term, evolutionary sense.

So, to many Darwin fans, Variation is a bit of an embarrassment, representing his failure rather than his success. Even Darwin himself found the experience of writing it an ordeal. By the end of what he later described as four years and two months of hard labor, when his interests had already moved on to other things, he wrote in a letter to his friend Joseph Hooker, “If I try to read a few pages I feel fairly nauseated … the Devil take the whole book”!

Variation under Domestication is nevertheless impressive. It continues the analogy Darwin used in Origin comparing the selective breeding of domesticated animals with the process of evolution by natural selection. Darwin wasn’t blind to the fact that domesticated animals change over time. They evolve. (In those days it would have been called the transmutation of species.) While evolution in wild animals is usually too slow to observe within a human lifetime, changes in domesticated animals could be brought about, by careful selective breeding, within just a few animal generations.

Equally important, Variation also presents a remarkable compendium of reflections and observations on traits occurring under domestication, both made directly by Darwin himself: in his own pigeon loft and greenhouses, and from the experience of others. Darwin was an energetic letter-writer and kept up a barrage of correspondence with everyone, the world over, who he considered might be of use, from the loftiest stud owner to the humblest gardener. He socialized with pigeon fanciers among the erudite, and at the pigeon shows he attended in the insalubrious bird fanciers’ underworld of London’s Spitalfields slums.

Some of Darwin’s own skeletons of domesticated pigeons. Darwin kept fancy pigeons for several years, conducting breeding experiments and carefully comparing their skeletons in an effort to understand the mechanism for evolution and for the inheritance of certain characteristics.

Many of the collected observations, although familiar enough to fanciers, have scarcely since been given any attention by the scientific community. And yet it is undeniably science. And science, moreover, increasingly shown to be of relevance to modern understanding. Traits ‘discovered’ in domesticated animals have been found to help explain the evolution of similar characteristics in wild animals. The more we understand about evolution, genetics and development, the more our domesticated animals, and the people who breed them, have to offer. The difficulty lies in convincing the scientific community of their value. The more easily information becomes available in modern times, the more we shut ourselves off from what we think we don’t want to know, or fail to recognize that other social genres might possess the answers we seek. So much of the knowledge of animal fanciers would be of benefit to biologists, if only they would pay attention— as Darwin did.

It’s not every author that gets a significant anniversary coinciding with a book they’re already working on. I began my book, Unnatural Selection both as an exploration of Darwin’s analogy and as a way of thanking my husband for his help with my previous book, The Unfeathered Bird. Husband is a domesticated animal nerd and a lifelong breeder of fancy pigeons—not for sport or exhibition, but as a way of understanding the inheritance of certain traits. He conducts the same sorts of experiments, and makes the same sorts of observations that would have delighted Darwin.So when I realized that my completion date had a chance of coinciding with the 150th anniversary of Variation under Domestication the timing seemed too good to be true.

Throughout, my book uses examples from a lifetime’s experience of domesticated animal breeding, making it a tribute not just to Darwin’s accomplishments, but his style of research and writing. Darwin too was happiest when he was observing living things and carrying out his own experiments. They ranged from testing the effects of seawater on seeds in an effort to understand the colonization of oceanic islands to studying the senses of earthworms by observing their responses to different musical instruments. One of my favorites is his method to test the correlation between eyesight and hearing in very young kittens. Darwin had observed that kittens appear to be unresponsive to sound until their eyes have opened at around nine days. This was how he did it: (1) creep up to a nest of kittens, carrying brass poker and shovel, being careful not to make any sudden vibrations; then (2) bash poker and shovel together to make as much noise as possible! The kittens slept on, unfazed.

We recently watched our little troupe of bantams foraging in the garden. (Being Husband’s birds, they’re not recognized breeds but a motley collection of interesting genetic traits.) There were obviously a lot of good things to eat under the woodpile, but only the birds with the trait for shortened limbs could squeeze into the small gap—the others had to remain on the outside and listen to them feasting. Darwin’s conclusion would have been the same as ours: if food had been scarce, the short-legged individuals would have a better chance of survival than the normal ones.

Unnatural Selection was for me five years and two months’ hard labor and, far from feeling nauseated, I’m more proud of it than of anything I’ve ever done. Its purpose is to illustrate the scientific value of selective breeding and encourage those who turn up their nose at domesticated animals to view them with a little more respect. Also to explain how evolution works using the same analogy that Darwin chose and to suggest that this analogy is even more appropriate than even Darwin realized. And to be a tribute to what Variation under Domestication might have achieved, had Darwin possessed that elusive missing piece to the puzzle.

How ironic, that for all his copious letter writing, the questionnaires he sent out to breeders of plants and animals around the globe, and the extensive reading and meticulous research with which he informed himself of every possible source of useful material, Darwin allowed one crucial contact to escape his notice. For there was someone, at exactly the same time, conducting very similar breeding experiments to his own and with the same purpose in mind—someone studying inheritance in pea plants in a monastery garden in Brno… Gregor Mendel.

 

Katrina van Grouw inhabits that no-man’s-land midway between art and science. She holds degrees in fine art and natural history illustration and is a former curator of ornithological collections at a major national museum. She’s a self-taught scientist with a passion for evolutionary biology and its history.

As a special celebration of the 150th anniversary of ‘Variation under Domestication,’ Katrina be posting images, articles and excerpts from Unnatural Selection on her Facebook page ‘Books by Katrina van Grouw’ from today, January 30th, until Darwin’s birthday on the February 12th.