Eutrusca
25-07-2006, 13:48
COMMENTARY: A decades-long experiment in Russia has indicated that the domestication of mammals resulted from selection for "tameness." AND, there are indications that humans may have self-domesticated as well! The search is on for the gene(s) which control aggressive and tame behavior.
Your thoughts?
Nice Rats, Nasty Rats: Maybe It’s All in the Genes (http://www.nytimes.com/2006/07/25/health/25rats.html?_r=1&th&emc=th&oref=slogin)
By NICHOLAS WADE
Published: July 25, 2006
On an animal-breeding farm in Siberia are cages housing two colonies of rats. In one colony, the rats have been bred for tameness in the hope of mimicking the mysterious process by which Neolithic farmers first domesticated an animal still kept today. When a visitor enters the room where the tame rats are kept, they poke their snouts through the bars to be petted.
The other colony of rats has been bred from exactly the same stock, but for aggressiveness instead. These animals are ferocious. When a visitor appears, the rats hurl themselves screaming toward their bars.
“Imagine the most evil supervillain and the nicest, sweetest cartoon animal, and that’s what these two strains of rat are like,” said Tecumseh Fitch, an animal behavior expert at the University of St. Andrews in Scotland who several years ago visited the rats at the farm, about six miles from Akademgorodok, near the Siberian city of Novosibirsk. Frank Albert, a graduate student at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, is working with both the tame and the hyperaggressive Siberian strains in the hope of understanding the genetic basis of their behavioral differences.
“The ferocious rats cannot be handled,” Mr. Albert said. “They will not tolerate it. They go totally crazy if you try to pick them up.”
When the aggressive rats have to be moved, Mr. Albert places two cages side by side with the doors open and lets the rats change cages by themselves. He is taking care that they do not escape to the sewers of Leipzig, he said.
The two strains of rat are part of a remarkable experiment started in the former Soviet Union in 1959 by Dmitri K. Belyaev. Belyaev and his brother were geneticists who believed in Mendelian theory despite the domination of Soviet science by Trofim Lysenko, who rejected Mendelian genetics.
Belyaev’s brother was exiled to a concentration camp, where he died, but Belyaev was able to move to Siberia in 1958 and became director of the Institute of Cytology and Genetics in Novosibirsk. There he was able to study genetics in relative freedom, according to a report prepared by Dr. Fitch after a visit to the institute in 2002.
Belyaev decided to study the genetics of domestication, a problem to which Darwin gave deep attention. Domesticated animals differ in many ways from their wild counterparts, and it has never been clear just which qualities were selected for by the Neolithic farmers who developed most major farm species some 10,000 years ago.
Belyaev’s hypothesis was that all domesticated species had been selected for a single criterion: tameness. This quality, in his view, had dragged along with it most of the other features that distinguish domestic animals from their wild forebears, like droopy ears, patches of white in the fur and changes in skull shape.
Belyaev chose to test his theory on the silver fox, a variant of the common red fox, because it is a social animal and is related to the dog. Though fur farmers had kept silver foxes for about 50 years, the foxes remained quite wild. Belyaev began his experiment in 1959 with 130 farm-bred silver foxes, using their tolerance of human contact as the sole criterion for choosing the parents of the next generation.
“The audacity of this experiment is difficult to overestimate,” Dr. Fitch has written. “The selection process on dogs, horses, cattle or other species had occurred, mostly unconsciously, over thousands of years, and the idea that Belyaev’s experiment might succeed in a human lifetime must have seemed bold indeed.”
In fact, after only eight generations, foxes that would tolerate human presence became common in Belyaev’s stock. Belyaev died in 1985, but his experiment was continued by his successor, Lyudmila N. Trut. The experiment did not become widely known outside Russia until 1999, when Dr. Trut published an article in American Scientist. She reported that after 40 years of the experiment, and the breeding of 45,000 foxes, a group of animals had emerged that were as tame and as eager to please as a dog.
As Belyaev had predicted, other changes appeared along with the tameness, even though they had not been selected for. The tame silver foxes had begun to show white patches on their fur, floppy ears, rolled tails and smaller skulls.
The tame foxes, Dr. Fitch reported, were also “incredibly endearing.” They were clean and quiet and made excellent house pets, though — being highly active — they preferred a house with a yard to an apartment. They did not like leashes, though they tolerated them.
American researchers have suggested that the foxes be made available as pets, partly to ensure their survival should the Novosibirsk colony be wiped out by disease.
[ This article is two pages long. Read the rest of the article. ] (http://www.nytimes.com/2006/07/25/health/25rats.html?pagewanted=2&_r=1&th&emc=th)
Your thoughts?
Nice Rats, Nasty Rats: Maybe It’s All in the Genes (http://www.nytimes.com/2006/07/25/health/25rats.html?_r=1&th&emc=th&oref=slogin)
By NICHOLAS WADE
Published: July 25, 2006
On an animal-breeding farm in Siberia are cages housing two colonies of rats. In one colony, the rats have been bred for tameness in the hope of mimicking the mysterious process by which Neolithic farmers first domesticated an animal still kept today. When a visitor enters the room where the tame rats are kept, they poke their snouts through the bars to be petted.
The other colony of rats has been bred from exactly the same stock, but for aggressiveness instead. These animals are ferocious. When a visitor appears, the rats hurl themselves screaming toward their bars.
“Imagine the most evil supervillain and the nicest, sweetest cartoon animal, and that’s what these two strains of rat are like,” said Tecumseh Fitch, an animal behavior expert at the University of St. Andrews in Scotland who several years ago visited the rats at the farm, about six miles from Akademgorodok, near the Siberian city of Novosibirsk. Frank Albert, a graduate student at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, is working with both the tame and the hyperaggressive Siberian strains in the hope of understanding the genetic basis of their behavioral differences.
“The ferocious rats cannot be handled,” Mr. Albert said. “They will not tolerate it. They go totally crazy if you try to pick them up.”
When the aggressive rats have to be moved, Mr. Albert places two cages side by side with the doors open and lets the rats change cages by themselves. He is taking care that they do not escape to the sewers of Leipzig, he said.
The two strains of rat are part of a remarkable experiment started in the former Soviet Union in 1959 by Dmitri K. Belyaev. Belyaev and his brother were geneticists who believed in Mendelian theory despite the domination of Soviet science by Trofim Lysenko, who rejected Mendelian genetics.
Belyaev’s brother was exiled to a concentration camp, where he died, but Belyaev was able to move to Siberia in 1958 and became director of the Institute of Cytology and Genetics in Novosibirsk. There he was able to study genetics in relative freedom, according to a report prepared by Dr. Fitch after a visit to the institute in 2002.
Belyaev decided to study the genetics of domestication, a problem to which Darwin gave deep attention. Domesticated animals differ in many ways from their wild counterparts, and it has never been clear just which qualities were selected for by the Neolithic farmers who developed most major farm species some 10,000 years ago.
Belyaev’s hypothesis was that all domesticated species had been selected for a single criterion: tameness. This quality, in his view, had dragged along with it most of the other features that distinguish domestic animals from their wild forebears, like droopy ears, patches of white in the fur and changes in skull shape.
Belyaev chose to test his theory on the silver fox, a variant of the common red fox, because it is a social animal and is related to the dog. Though fur farmers had kept silver foxes for about 50 years, the foxes remained quite wild. Belyaev began his experiment in 1959 with 130 farm-bred silver foxes, using their tolerance of human contact as the sole criterion for choosing the parents of the next generation.
“The audacity of this experiment is difficult to overestimate,” Dr. Fitch has written. “The selection process on dogs, horses, cattle or other species had occurred, mostly unconsciously, over thousands of years, and the idea that Belyaev’s experiment might succeed in a human lifetime must have seemed bold indeed.”
In fact, after only eight generations, foxes that would tolerate human presence became common in Belyaev’s stock. Belyaev died in 1985, but his experiment was continued by his successor, Lyudmila N. Trut. The experiment did not become widely known outside Russia until 1999, when Dr. Trut published an article in American Scientist. She reported that after 40 years of the experiment, and the breeding of 45,000 foxes, a group of animals had emerged that were as tame and as eager to please as a dog.
As Belyaev had predicted, other changes appeared along with the tameness, even though they had not been selected for. The tame silver foxes had begun to show white patches on their fur, floppy ears, rolled tails and smaller skulls.
The tame foxes, Dr. Fitch reported, were also “incredibly endearing.” They were clean and quiet and made excellent house pets, though — being highly active — they preferred a house with a yard to an apartment. They did not like leashes, though they tolerated them.
American researchers have suggested that the foxes be made available as pets, partly to ensure their survival should the Novosibirsk colony be wiped out by disease.
[ This article is two pages long. Read the rest of the article. ] (http://www.nytimes.com/2006/07/25/health/25rats.html?pagewanted=2&_r=1&th&emc=th)