In the succeeding generations some chickens were still almost solid brown, some had brown and white feathers mixed together like a tweed, and others were mostly white. The brown chickens had mature feathers, but the feathers on the white chickens were immature, soft, and runty. The central spine of each feather was short, soft, and limp, and the feather barbs (that’s the feathery stuff that grows out of the shaft) were super-soft, almost like down.
Emotionally, the brown hens were the calmest birds, the brown and white hens were nervous, and the white hens were extremely anxious and agitated. When you walked into the barn they would go berserk squawking and hopping up and down. They were extremely hyperactive and frantic-acting. Then when they got old they’d start beating their own feathers off against the sides of their cages, until they were half nude. They were violent, too, and would peck and kill each other if they had a chance.
But nobody did anything about it because it was another case of the change happening slowly enough that the humans adjusted to the new chicken reality and perceived it as natural. The bad became normal. Finally one farmer bought some brown Hutterite chickens that they housed close to the white chickens, and the difference jumped out at them. The brown chickens could lay as many eggs as the white chickens, although they needed 10 percent more feed, but they were calm birds who didn’t show any signs of agitation or anxiety. When they got old they still had all their feathers.
In the hens’ case I think the reason for their psychological problems is less mysterious than whatever caused the roosters to become violent rapists. Pure white animals (and people) have more neurological problems than dark-skinned or dark-furred animals, because melanin, the chemical that gives skin its color, is also found in the midbrain, where it may have a protective effect.1 You see all kinds of problems in white animals. Dalmatians with the highest ratio of white fur to black are getting close to true albinism. They’re more likely to be deaf than other dogs, and they are often airheads you can’t train. Black-and-white paint horses can have problems, too. It’s not unusual for a paint horse to be plain crazy, especially if he has blue eyes.
You see quite a few problems in animals with blue eyes. I met a paint horse once who had one brown eye and one blue eye, and he clearly had a horse version of Tourette’s. Every sixty seconds his whole body would flinch uncontrollably. And it’s fairly well known that if you mate two blue-eyed huskies the offspring can have problems.
The color of the animal’s skin is more important than the color of its fur. If its skin is dark, that’s good. The inside of a dog’s mouth should be mostly black, with some white.
True albino animals are much worse. A study by Donnell Creel, research professor of ophthalmology and visual sciences at the University of Utah, looked at all the problems and differences in albino animals, and concluded that researchers should not be using albino animals in their research, because albino animals are not normal. Albino animals like the white laboratory rats people used for years probably aren’t even good for drug research, because melanin binds to some of the chemicals used in medications, so an albino animal’s response to a medication can be completely different from a non-albino animal’s.2
In the wild there are very few all-white animals apart from polar bears and the occasional white wolf. But polar bears and white wolves both have dark skin; it’s just their fur that’s white. They aren’t albino. It’s when the skin is all pink or all white that the animal has problems. Albino animals are occasionally born in nature, but their survival rate is low because of all their problems. I am definitely against humans doing things like deliberately breeding albino Doberman pinschers because they look so pretty. These animals are not normal, and they suffer. People who own albino Dobermans report that their dogs have poor vision, intolerance to sunlight, skin lesions, and problems with temperament, usually aggression. In one survey 11 percent of owners said their dogs had bitten people.3 That’s an enormously high number considering how rare dog bites are in comparison to the number of dogs living with humans.
So it’s not surprising that an all-white chicken would have a lot of emotional problems, though we don’t know why breeding a chicken to need less food would turn her feathers and skin white in the first place. How is feed conversion related to feather color? We don’t know, and we could probably learn a lot about the biology of emotions if we studied the unintended behavioral changes that have come out of these selective breeding programs.
Whenever I talk about white animals in my lectures, people want to know whether what I’m saying applies to white and black people. The answer is that it doesn’t, because white people aren’t really white. White humans have melanin in their skin, and get tan when they spend time in the sun. Caucasians’ skin color evolved the same way everyone else’s skin color evolved, through the forces of natural selection operating without conscious human interference. That’s why you see emotional and behavioral differences in all-white animals that you don’t see in “all-white” people.
Nature doesn’t evolve a Dalmatian. The Dalmatian has been artificially bred to be mostly white, and is starting to be closer to albinos than to normally pigmented animals. It’s not an albino, but it’s getting there.
HOW PEOPLE CHANGE ANIMALS’ EMOTIONS
So far I’ve been talking mostly about accidental changes that come out of single-trait breeding programs, but people also change animals all the time in a much more natural way. That happens because people are in charge of domestic animals’ lives, and we make or influence the decisions about which animals get to reproduce and which animals don’t.
A lot of the time—maybe even most of the time—these changes aren’t bad at all. Some of the changes might even be good. Here’s an example. Several years ago I visited the pigs at two multiplier units within the same company but located in different parts of the country. A multiplier unit is a breeding colony that raises female pigs to sell to farmers. The pigs all belong to the same genetic line, and are very close to each other genetically because breeders use a fair amount of inbreeding to keep consistency in the animals. The pigs in these two units started out the same in every way, genetically, physically, and emotionally.
But by the time I saw them, the pigs at the two units had developed completely different personalities. The pigs at one of the multipliers were much more excitable and hyper, while the pigs at the other one were calm and easygoing. It was the same story as the rapist roosters: none of the humans had any idea they’d evolved a whole new pig. They never visited each other’s farms, so they didn’t know the pigs’ personalities had diverged. That’s what I mean by natural—nobody was doing anything on purpose to affect the pigs’ evolution. It just happened.
When I took a look at the pigs’ lives in the two units I found the cause: the unit with the calm pigs had been selecting for placid temperaments unknowingly. In a multiplier unit each female pig has to be individually evaluated for breeding stock. The employees weigh her and look at her teeth, her udder, and the overall conformation of her body. Conformation means that the different parts of the animal are in good proportion to each other. The only difference between those two units was that one unit had a good, stable scale and the other unit had a crappy scale with a needle that jumped all over the place. The unit with the crappy scale couldn’t get a reading on the more hyper pigs, and I’m sure they were culling the hyper ones and keeping the calm ones.
They didn’t have a conscious plan to cull the hyper pigs; they just ended up doing it “naturally” because the scale was defective. Since the farm with the good scale could get reliable weights on all the pigs whether they stood still or not, there was no accidental selection pressure to get rid of the hyper ones. That shows you how sensitive animal genetics is to the environment: something as simple as how well the scale is working at a multiplier unit can change a pig’s inherited emotional makeup.
Accidentally shaping a pig’s genetics to create calmer animals is an example of a “natural” human selection pressure
that’s not only harmless but might be good for the animals. People and domestic animals have been together for a long time, and domestic animals have been evolving in response to humans for years. A pig wouldn’t be a pig if it hadn’t been evolving in the company of humans. He’d be some other kind of animal, like a wild boar. So probably a lot of the incidental selection pressures we put on animals are either harmless or good for the animal.
One genetic development I am concerned about, though: we’re seeing more and more lameness in pigs today.
A PUPPY BRAIN AND GROWN-UP TEETH
Human selection pressure on animals’ emotional makeup is probably the most obvious in dogs. I do not like what breeders are doing to purebred dogs. Breeders have made collie faces thinner and thinner, for example, leaving less and less space inside the skull for their brain. A dog needs a nice, wide skull to house its brain, and if you look at old paintings of collies from the beginning of the twentieth century that’s what you see: Lassie with a broad, flat forehead.
By the early 1980s collie heads had gotten so narrow that a friend of mine who grew up with a collie on a farm in the 1950s and 1960s told me she didn’t recognize the collies in her neighborhood as belonging to the same breed as her childhood pet. Somehow she got the idea that the “needle-nose collies” her neighbor owned came from a whole different line of French collies she’d never seen before! (I don’t know how she got France in there, but she did.)
The problem isn’t just the reduced space for the collie’s brain; it’s also the weird shape of the skull. I would expect to find that the progressive narrowing of their faces has distorted collie brains anatomically. But whatever the cause, their intelligence has gone down so far that I call collies brainless ice picks. It’s a horrible thing to have done to a nice, and beautiful, dog.
Making collies stupid wasn’t the point, of course. Collie breeders probably just wanted to exaggerate one of the most distinctive features of the collie dog, which is its long thin nose. But in the process of breeding for super-elongated noses, they bred out a decent-shaped skull.
People probably put much more constructive selection pressures on mutts. A mutt who bites people, or who destroys the house by chewing everything in sight, has an excellent chance of being sent to the pound or put to sleep. That means his genes will be removed from the gene pool. Just about the only mixed-breed dogs who get to reproduce are the ones who are well adapted to living with people—and good at getting out of the yard. (I know owners are all supposed to neuter their pets, but a lot of owners don’t. That’s why we have so many mutts.)
With purebred dogs the selection pressures are completely different, and a lot of them are negative. For one thing the breeders are consciously trying to meet American Kennel Club standards, which are heavily tilted toward physical criteria, not emotional or behavioral. Moreover, professional breeders rarely if ever think about what their beautiful dogs are going to do to an owner’s house, and they usually don’t call the people who’ve bought their puppies to follow up on the puppy’s behavior. All the puppies in a litter could have emotional or behavioral problems and the breeder could know nothing about it. So there’d be nothing to stop him from continuing to breed the parent dogs and producing more puppies with the same problems.
The other factor shaping purebred dog genetics is owners’ higher tolerance for difficult behavior in a beautiful, expensive animal. A person who has spent $1,000 on a dog is going to put up with a lot more bad behavior than a person who has spent nothing. And if the owner is planning to breed the dog he won’t stop to think maybe a dog who is horrible to live with shouldn’t have puppies.
This is just a theory, but there’s plenty of evidence on the emotional and behavioral problems of purebred dogs versus mixed breeds to support the hypothesis that the selection pressures on mutts are more constructive. For one thing, mutts are physically healthier, because the bad traits of purebreds, such as hip dysplasia, disappear just one or two generations away from the purebred line.
Mutts are also more likely to be emotionally stable, for a couple of reasons. One is that negative emotional traits will tend to get bred out of mixed-breed dogs, because mutts with major emotional problems like aggression or severe separation anxiety are probably more likely to be sent to shelters than purebreds. The other is that no one is practicing single-trait selective breeding with mutts, so mutts are not going to be turned into monster dogs the way the roosters were turned into monster rapist roosters.
In terms of behavior, the most important difference between mutts and purebred dogs is that purebreds are responsible for the large majority of fatal dog bites, not mutts. One twenty-year survey found that purebreds were responsible for around 74 percent of all fatal dog attacks on people. Seeing as how purebreds are only around 40 percent of the total pet dog population in the country, that’s pretty bad.4
There have to be at least a couple of reasons for this. One, I’m sure, is that aggressive mixed-breed dogs get put down much more quickly than aggressive purebreds. But I think purebred dogs also suffer some of the negative emotional and behavioral effects of single-trait selection. Often breeders will mate their dogs so as to exaggerate one distinctive trait in the breed, like the rough collie’s long thin nose. Since, as I mentioned earlier, any time you selectively breed for one trait, eventually you end up with neurological problems. Once you start getting neurological problems, one of those problems is likely to be aggression, so it doesn’t surprise me that purebreds have more aggression problems than mutts.
Probably the most stable mutts are mixed-breed dogs whose underlying skin color isn’t too light. Hair color doesn’t matter; you just want to be sure you’re not adopting an animal who has too many albino characteristics, such as blue eyes, a pink nose, and white fur covering most of its body. A small amount of white fur is perfectly fine, but you should avoid a white or light-colored coat combined with either blue eyes or a pink nose.
The fact that mixed breeds are so much less aggressive is good evidence that the selection pressures on mixed breeds are more constructive. My impression is that mixed-breed dogs are easier to live with in a lot of ways. I don’t think there’s any hard data on how much shoe chewing mixed breeds do compared to purebreds, but there’s a lot of anecdotal evidence that purebreds, or at least certain breeds of purebreds, do more of it than mutts.
A friend of mine told me a typical story about mutts versus purebreds on chewing. Altogether she has owned two mixed-breed black dogs, and one yellow Labrador retriever. Labs, in case you didn’t know it, are notorious chewers. Even though my friend got all three dogs as young puppies, the mutts did hardly any destructive chewing at all, whereas the yellow Lab chews everything she can get her teeth on. She’s destroyed shoes, toys, pencils, pens, one corner of the rug in my friend’s office, the fringe on the oriental carpet in the living room, three different wooden chair legs, several T-shirts that were left lying around, two blankets, a couple of books, several Tupperware containers, a sweatshirt, all the balls in the house, and she chewed the electric cord to the dehumidifier in half. That’s just the list my friend could remember off the top of her head, and it’s only the indoor list. Outdoors she wrecked a $400 hot tub cover, chewed up the wood framing around the neighbor’s picture window, and, back in my friend’s yard, gnawed clear through the trunk of a whole lilac tree, just like a beaver. The dog is one and a half years old now, and she’s still going. She’s doing a little better, because they’ve been working on training her to chew her rawhide bones instead of everything else, and because she’s a little more mature. But she’s still destructive. My friend estimates she’s done $1,000 worth of damage at a minimum, not counting the two rugs that can’t be repaired and would cost a lot to replace.
All Labradors chew like that; it’s built into their genetic makeup. Golden retrievers are probably just as bad. I don’t think anyone knows why, although with Labs it may be related to their obsessive overeating. (Although goldens belong to the same genetic group
as Labs and all the other hunting dogs,5 they don’t overeat the way Labs do, so they may not chew for the same reasons.) I heard one owner call Labs “opportunistic eaters”—they’ll eat just about anything you give them, including grapes and bananas. They love food so much you can train them to sit and heel just using little pieces of dry kibble. They are always hungry and will pack on the pounds if you let them eat whatever they want. I suspect it’s this drive to eat that makes them need to chew everything in sight, because Holstein cows are the same way. Holsteins have been bred to eat a huge amount of feed so they can produce more milk, and they also have a compulsion to lick and mouth things and to manipulate objects with their mouths. Their behavior is so extreme that if a tractor gets left in their pen they’ll lick the paint off and chew up all the hydraulic hoses. They’ll destroy it, whereas beef cattle will just sniff it. Perhaps when you genetically increase an animal’s desire to eat, you also increase its desire to use its mouth.
Of course that raises the question of why Labs have such massive appetites, and I don’t know the answer to that. They were originally bred to be fishing dogs in Newfoundland, and they’re impervious to cold and pain, so maybe the extra fat helps them stay warm. I don’t know. That’s why the quirks of selective breeding are so fascinating. If we knew why breeding a Lab to be a Lab also means breeding a Lab to be a compulsive overeater we might have a good idea of what causes most people to overeat, while some people can stop eating when they’re full.
Animals in Translation Page 10