LiveScience provides a brief background on the study, which uses a population of rats now almost 40 years in captivity:
"The roots of this study date back to 1972 when researchers in Novosibirsk, in what is now Russia, caught a large group of wild rats around the city. Back at the lab, the researchers arbitrarily separated the rats into two groups. In one group, called the tame rats, the scientists then mated the friendliest rats, those that tolerated humans, with one another, and in the other group they mated the most aggressive rats with each other. "
The study itself includes more detail on the development of its subject population:
"To select the animals, their response to an approaching human hand was observed, and the rats showing the least and the most aggressive behavior were allowed to mate within the two lines, respectively. The initial response to selection was rapid and then slowed, so that little change in behavior from generation to generation has been observed in the last 10–15 generations, although the selection regime has been continued to the present. Today, the 'tame' rats are completely unafraid of humans, they tolerate handling and being picked up, and they sometimes approach a human in a nonaggressive manner. By contrast, the 'aggressive' rats ferociously attack or flee from an approaching human hand."The rapid development of 'tameness' through selective breeding is interesting to those of us who believe domesticated animals can be produced rather quickly. The remarkable Russian fox experiment is relevant here and is referenced in this rat study. There is an ongoing debate about the possibility of rapid domestication, even numerous independent domestications, in ancient dogs. In the falconry context, I'm convinced that selective breeding of Harris hawks (Parabuteo unicinctus) has produced demonstrably tamer and more cooperative birds in as few as five generations---I've been witness to this in my lifetime.
The popular reporting on this study seems to focus on the notion that domestic animals and their wild counterparts could be separated by few or even a single gene; that somehow all of what makes a "wild animal" wild is encapsulated in one trait.
As anyone who has lived and worked with animals both wild and domestic can tell you, it's nothing like that simple.
Animals, regardless their origins or number of generations in captivity, are incredibly (irreducibly) complex beings, individuals every one. Their complexity mirrors their environments, which even in the Spartan conditions of a laboratory may be more variable than we like to assume. In "the wild," those variables are innumerable and subject researchers to principles of uncertainty, acknowledged or not.
The result is enormous diversity and confounding truths. Very tame animals, for example, are common in the wild. Island endemics like those of the Galapagos are well known, but any falconer with sufficient experience can tell of wild-taken hawks flying freely to hand in a matter of days and behaving entirely at ease in human company. Steve's falconry mentor even had a pair of free-roaming goshawks eating from his hand.
Conversely, stories of domesticated dogs attacking the hand (this study's key signature of the 'wild type') are so commonplace as to serve as the classic example of what is not news!
What can the science of genetics tell us about these cases?
Volumes, I'm sure. But I'm equally sure that the complicated truth about our genes and our environment will never be wholly revealed in the lab. It may never be wholly revealed at all, but merely intuited and approximated by those (like falconers, sheppards, hunters) whose lives intersect and entwine with wild and domestic animals. For many, that will be revelation enough.
12 comments:
brb, finding the gene for being fascinated with nature.
Oh! I've got that one!
Jah, tameness, fearlessness, and domestication are not the same thing. How could there be one gene?
My khaki ducks are totally domesticated beings. They are also terrified of people and will flee a hand -- have been since hatching. However, they are "tame" in terms of not being aggressive towards people. When I can catch them, I can pick them up and carry them with no struggle or danger of being scratched or bitten.
My guineas were the same way, though perhaps less "domesticated" than the ducks. They were fearful of being touched, but less fearful in general compared to the ducks. And they'd continue to fight handling until subdued.
The chickens, on the other hand, are completely tame, and sometimes must be chastised for being "aggressive" -- whether that's a simple willingness to peck a hand, or a rooster charging with spurs and beak engaged. The "friendliness" of the nebbiest hens and the "aggression" of the rooster are two sides of the boldness coin.
The colony of puppymill dogs that I have been working with (in custody/ held as evidence pending the cruelty trial) are, as are all dogs, completely domesticated -- and were not tame when confiscated. Unlike a wild animal, most tamed up in a matter of weeks with an hour or so a day of work. They also show shockingly low levels of aggression towards humans.
Faddists claim that all aggression is founded in fear. Poppycock. The most fearful beings are too scared to be aggressive. And one can train some highly reliable and impressive aggressive behavior in a dog with the right genetics, by building up that dog's confidence.
One of the really interesting things the popular press pays absolutely no attention to is the profound effect epigenetics can have on animal populations.
Lines of genetically identical plants exihibit varying phenotypes - despite being (genetically speaking) clones of each other. Thise variation isn't just due to getting different amounts of water or sun or nutrients, it's also due to epigenetic changes in the daughter plants. And - in some cases these epigenetic changes are passed on to *their* offspring.
Some have proposed that the rapid phenotypic changes seen in the Belyaev foxes was due more to epigenetic than genetic change.
So, what does the 'tameness' gene do when there aren't any human beings around? Just make the animal really gullible...?
The general public really needs to take some of these "scientific" experiments with a grain of salt(sometimes a fifty lb. block would be more appropriate) and realize that, interesting as some of the subjects are to discuss, a lot of these professional scientists don't have a lick of horse-sense, and are so anxious to get a paper published and make some great new discovery, that they often overlook what the farmer down the road has always known! One of my favorite "discoveries" was an experiment done with beagles in cages in a laboratory(obviously frustrated and bored out of their minds), which somehow "proved" that domestic dog barking was simply a "release mechanism" with no meaning or ability to communicate at all! Obviously these intellectuals had never kept a dog at home, or they would have learned quickly that dogs have very distinctive barks and other noises that mean very specific things, not only to other dogs, but that even the dull primates they live with can eventually pick up on!....L.B.
This is on an apparently semi-parallel track to the work that Dr. Mark Neff is doing at the UC Davis School of Veterinary Medicine.
He is looking for a genetic basis for the pointing instinct in bird dogs. The goal is to identify a genetic basis for behavior, which could indicate a research direction for investigation of behavior-linked genetic material in the human genome.
Mike I suppose they'll have us all figured out pretty soon. What then?
L.B., Rina barks once, sharply, at the back door when she has done her business and is ready to come back in. But when she sees me leave with the kids to the pool down the street, she howls.
Part of the problem with studying dogs in the laboratory is one of the problems with reductionism in general; some systems you cannot break down without also destroying the system and eliminating all hope of useful information. The nutshell way I usually put it is that it's the same reason you can't take a cat completely apart, put it back together, and still have a functional cat.
Dogs in a pack or dogs in a home- dogs being social with distinct relationships in general- are the "system". Isolate the dog and deprive it of relationships, and you won't get much useful information about dog behavior.
Matt wrote:"Mike I suppose they'll have us all figured out pretty soon. What then?"
Welcome to the future.
Imagine the consequences of genetic testing... 'they' can identify 'bad guys' before they are born, and divert them into a rehab program at birth? Scares the hell our of me.
Don't worry, Mike Spies, if they start genetic testing for bad guys, they'll probably be a grandfather clause to exempt us old bad guys......L.B.
This is a killer post.
I read it when it first came out, and at the time I was quite in love with the simplicity of the argument laid about by people like Raymond Coppinger, even though I did have a certain amount of quibbles with some of his insistence that dogs were nothing more than mentally delayed wolf puppies.
Over time, I've been exposed to more literature and more criticism, and those quibbles I had are actually major problems that these models can't answer.
BTW, they essentially gave up looking for the genes that separate tame foxes from nontame ones. I believe the experiment now has folded in Russia, though I think it still goes on at Cornell.
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