Tuesday, September 04, 2018

An Illustrated Anatomy of Unnatural Selection

Unnatural Selection by Katrina van Grouw is a grand and lavishly illustrated book five years in the making.

Published on the 150th anniversary of Charles Darwin's The Variation of Animals and Plants Under Domestication, this is an old-fashioned book leavened and informed by modern genetics and 150-years of global selective breeding.

I say the book is "old-fashioned" because Ms. van Grouw has illustrated the book with over 400 excellent anatomical and taxonomic drawings which illuminate the astounding variation to be found in the feet of chickens, skulls of dogs, body structure of pigs, and posture of ducks (to name just a few).

The drawings, rendered in sepia ink, speak of the 19th century rather than the 21st; a clear call back to Darwin and the great age of evolutionary illumination. This is scientific illustration at its finest.

The book is also old-fashioned in that rather than structure itself around the modern conversation about the relative success and failure of breeding at the hand of man, this book is structured around Darwin's four-pronged evolutionary frame: Origin, Inheritance, Variation, and Selection.

Ms. van Grouw was well positioned to write this book; she is the former Curator of Birds at the British Natural History Museum, the second largest ornithological reference collection in the world. Her husband, Hein van Grouw, was Senior Collection Manager of Birds and Mammals at the Natural History Museum in the Netherlands. Between them both, they know the astounding variety to be found in the natural world

But, as Ms. van Grouw notes, the real story of the last 300 years is not what Mother Nature and Father Time have produced together, but what the hand of man has been able to accomplish by putting unnatural selection into hyperdrive. 

Taxonomists have largely ignored this phenomenon, weighted down by the clunky conventions of Linnaean classification which brook no room for hybrids or for dramatic differences within a species.

Ms. van Grouw herself admits to once having looked down her nose at batty people obsessed with strange pigeons, odd chickens, and bizarre goldfish:

How foolish I was not to take fanciers more seriously. Oblivious was I to the fact that many of the men (and women too) in their own way knew at least as much about birds as any museum ornithologist or field birder. In their highly skilled hands pigeons are but putty that can, within a few generations, be molded into any shape and be remade in virtually any color. Fanciers can fast-forward evolution like an H.G. Wells time machine. They can transfer a single trait from one variety to another without introducing unwanted traits; change a posture from horizontal to vertical; lengthen feathers in one body part and not another; or produce new combinations of colors and patterns.

Ms. van Grouw is on to a solid idea; that there is a great deal to learn from the fanciers. What's missing in this book, however, is exactly what that is.

We are treated to terrific illustrations of the variety of pigeons, pigs, chickens, ducks, and geese created by the hand of man, but no real detail as to why some species have been such smash successes, while others have slid into oblivion.

For example, we get a terrific tour of the varieties of chicken morphology, but nowhere are we told the story of the 1948 Chicken of Tomorrow contest sponsored by the A&P grocery store chain.

It's not a small omission; chickens are far and away the most common birds on earth, and the Arbor Acres bird that won that 1948 contest was a global game changer.

Thanks to unnatural selection alone (no hormones are used) today's meat chickens are more than twice as big, in half the time, at a cost of less than half the feed per pound, and with one fifth the mortality of their brethren 65 years ago.

And what about egg production? Here too unnatural selection has resulted in tremendous gains in production, with hens moving from 150 eggs a year in the 1930s, and a mortality rate of about 40 percent, to 250 eggs per year, and a mortality rate of just 5 percent.

And it isn't just chickens that has seen astounding gains due to selective breeding at the hand of man. Improved efficiency in milk production has enabled the U.S. dairy industry to produce 186 billion pounds of milk from 9.2 million cows in 2007, as compared to only 117 billion pounds of milk from 25.6 million cows in 1944.

What about beef cattle? Here too selective breeding is at work, with steers and heifers adding 150-170 lbs in size as compared to their brethren just 20 years ago.

None of this phenomenal increase in production is detailed in Unnatural Selection, nor are the selective breeding gains made in honey bees, silk worm, potato, yeast, corn, and aquaculture noted.

Even as the wins of unnatural selection go unheralded, so too are the failures of selective breeding left unobserved.  For example, we are told that the bulldog has changed dramatically since the mid 19th Century, but we are not told who did this or why, nor are we told that the current English Bulldog generally cannot breathecannot mate on its own, cannot whelp on its owns, and is dead within 6 years.

The production success and failure of animals and plants under domestication is a huge part of the real story of unnatural selection, but it's one that Ms. van Grouw almost entirely ignores.

It's unclear. It could be that she simply sees the world through the lens of someone who used to manage a massive ornithological reference collection. A trained artist, she is more focused on the morphology of bone, feather, and horn than on what lies underneath: egg and honey production, muscle mass, and health. And so instead of tales of success and failure due to unnatural selection, we get a simple detailing of the astounding variation that has been expressed by humans rearranging the somewhat plastic building blocks of life.

This is an important story and should be told. There are fascinating things to learn about twisted canaries and pigs bred for extra vertebra. We learn of chickens missing tail bones, naked neck tumbler pigeons, and geese with feathered toupees that cover the unnatural holes at the back of their skulls.

But while this is interesting, it is also a little unsatisfying because there seems to be no central thesis holding the book together.

The very title of the book, Unnatural Selection, suggests it will cover more than morphological variation. After all, if something is unnatural -- man, women, or process -- it suggests some level of deviancy, whether for good or ill. What is that deviancy, and why is that deviancy?  That's the story that seems to be missing.

We are told that humans have been busy creating strange new breeds of pigeons, chickens, and dogs for hundreds of years, but there is no investigation or explanation as to why this has been done.

We are told the stock shows were created because people wanted to renew their contact with animals after the demise of canine pit fighting (page 229), but that's nonsense. Dog fighting, cock fighting, and rat pits attracted an entirely different crowd than the pet and stocks shows. The real history is that stock shows grew out of the need for Robert Bakewell and his followers to demonstrate an economic value for their new forms, created within enclosures where sire selection was now carefully controlled.  Stock shows to promote new and improved breeds of sheep and cattle soon added pigeons, chickens, and dogs to their venue, and the modern world of "the fancy" was born.

Bakewell barely gets a passing mention by van Grouw, and the enclosure movement is not mentioned at all, despite the fact that it is enclosed fields, cages, chicken houses, kennels, and tanks that have created the unnatural selection that drives the frenetic variety we see in the world of domestic animals today today.

Ms. van Grouw mentions the genetic "islands" created by closed registries within the Kennel Clubs, but does not detail the rising levels of disease, dysfunction, and deformity that have resulted.  It is just an accident that On the Origins of Species and the first formal dog show appeared in the same year?  How did The Variation of Animals and Plants Under Domestication, published in 1868, spark the creation of the Kennel Club in 1873, and how did the work of Darwin's cousin, Sir Francis Galton, drive the closing of Kennel Club gene pools only a decade or two later?  Ms. van Grouw's work, carefully arranged around chapters pegged to origin, inheritance, variation, and selection, miss this important history, and thus much of the story.

Back in 1968, Steward Brand wrote that "We are as gods and might as well get good at it."

In the creation of breeds and even new species, we are acting as gods. But are we any good at it?  The answer is not an unqualified "no" or "yes" -- it's more complicated than that, but here too Ms van Grouw misses the question as well as the answer.

The short story is that, measured on a pennies-and-pounds axis, unnatural selection on the farm appears to be largely a success. Along with more meat, milk, and eggs created with fewer inputs, we are also have more corn, tomatoes, and other foods cultivated from every acre.

What's the secret? Visit any garden center, and you can see it on the tag of nearly every rose bush: hybrid.

Our fields are full of hybrid seed corn. The black beef cow that appeas to be pure Angus almost certainly has a little Brahma coursing through its veins.  Outcross and hybrid vigor drive forward all things, both on the farm and in nature.

And so where is unnatural selection failing?

Most obviously it is failing in the world of "the fancy" where variety without any larger point or unit of production is celebrated.  Here were find the twisted bodies of bizarre chickens, canaries, ducks, and pigeons. Rather than outcrossing to boost production, the show fancy typically closes down gene pools in order to "lock in" a mutation or restrict breeding to recessive types. The typical Kennel Club dog, for example, saw its breed registry closed with less than 40 animals on its roles. And what happened next?  Predictable levels of inbreeding leading to rising levels of disease and genetic failure.

But so what?  Without a pennies and pounds axis -- without any goal other than to express a new morphological form and perhaps win a ribbon -- the defective and deformed is maintained solely as a side-show freak.

Ms. van Grouw notes that "animal fanciers talk a lot about fitness for original purpose," and goes on to note that in the case of bulldogs "I would argue that it's impossible to maintain fitness for purpose at a theoretical level and you might as well settle for just fitness."

But we are left hanging. Ms. Grouw does not finish the idea or illuminate the larger problem which is that Kennel Clubs afford zero points for health, zero points for temperament, and zero points for work.  How can you improve a breed if you have no meaningful axis on which to measure?

As an overview of the morphological potential for diversity due to selective breeding at the hands of man, Unnatural Selection is a qualified winner.  It would have been better if Ms. van Grouw had left her comfort zone of birds a little more, and ventured deeper into the world of horses, silk moths, coffee beans, and cotton. Of course no book can cover the sum total of all variation of animals and plants under domestication, but it would have been nice to see at least a few plants and insects given their due.

The main failure, however, is that no larger message or synthesis is presented.  Why has man worked so hard to express variety in plants and animals, and what can we learn from both success and failure?  How might this history inform the world of tomorrow, with cloning, CRISPR, and other forms of genetic modification and selection looming on the very near horizon?

As an evolutionary anatomy book, Unnatural Selection hits its mark, but as a guide to the past or future of unnatural selection, it leaves most of the story untold.


geonni banner said...

I got my copy a couple of weeks ago. I'm satisfied that it is indeed an excellent evolutionary anatomy book. Worth the price for just the illustrations. So now I'm waiting for Terrierman's volume to go on the shelf next to it - with the rest of the story.

Jennifer said...

So? Someone, someone, that is, with less of a museum background and attitude, and a scope that looks beyond vertebrata, needs to write another book. Sounds like this book provides a wonderful basis for going some steps further and considering moral and ethical questions along with morph-ology (pun intended).

P.s. "Unnaturally Seleted" would be a good title.

PBurns said...

Worth the price to buy and the time to read; no question.