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Dmitri Belyaev
From Wikipedia, the free encyclopedia
Dmitri Belyaev (1917-1985) - a Russian scientist, academician. In the 1950s Dmitri Belyaev and his team spent many years breeding the silver fox (Vulpes vulpes) and selecting only those individuals that showed the least fear of humans. Eventually, Belyaev's team selected only those that showed the most positive response to humans. He ended up with a population of foxes whose behavior and appearance was significantly changed. After about ten generations of controlled breeding, these foxes no longer showed any fear of humans and often wagged their tails and licked their human caretakers to show affection. They also started to have spotted coats, floppy ears, and curled tails.
At the time, biologists were puzzled as to how dogs evolved to have different coats than wolves. They couldn't figure how dogs got those genes from wolves. Belyaev saw his foxes as a perfect opportunity to find out how this happened. He and his colleagues began performing tests on the animals. When they checked the adrenaline levels of the domesticated foxes, they found that they were significantly lower than normal. This is feasible, because foxes that are not afraid of humans are going to produce less adrenaline around them. This explains the foxes' tameness, but it doesn't really explain their multicolor coats. The scientists theorized that adrenaline shares a biochemical pathway with melanin, which controls pigment production.
Quote from NOVA's 'Dogs and More Dogs' program
NARRATOR: Suddenly, it all started to make sense. As Belyaev bred his foxes for tameness, over the generations their bodies began producing different levels of a whole range of hormones. These hormones, in turn, set off a cascade of changes that somehow triggered a surprising degree of genetic variation.
JAMES SERPELL: Just the simple act of selecting for tameness destabilized the genetic make up of these animals in such a way that all sorts of stuff that you would never normally see in a wild population suddenly appeared.
Dmitri Belyaev was director of the Institute of Cytology and Genetics (IC&G) of the Russian Academy of Sciences from 1959-1985. He made significant contributions to the establishment of the IC&G and made efforts in the restoration and advancement of genetics in the USSR.