Sentences with phrase «for tameness»
In a renowned study started back in the 1950s, Russian researchers found that captive silver foxes bred for tameness also exhibited a suite of other traits, such as white patches of fur on their heads, curly tails, «feminized» faces with shorter snouts and floppy ears, and skulls in males that weren't much larger than in females.
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The work has shown that selecting for tameness alone can also produce a whole suite of other changes (curly tails, droopy ears, spotted coats, juvenile facial features) dubbed the domestication syndrome.
Experimental selection for tameness in silver foxes [7], rats [8,9] and mink [10] have shown the power of the directed pathway of domestication.
Selecting animals for tameness, they said, could alter genes that control a group of developmentally important cells called neural crest cells.
Changes in body size, reproduction and metabolism happened quickly, even though the researchers were only choosing birds for tameness.
From the beginning, the researchers took great pains to select birds only for their behavior: Jungle fowl were tested for tameness at 12 weeks old, before they reached sexual maturity.
The foxes were bred using selection criteria for tameness and with each generation, they became increasingly interested in human companionship.
Darwin also was the first to discover that selective breeding for tameness produced similar side effects in different animals, including smaller brains.
Recent research has found that a domesticated strain of rat selectively bred for tameness almost never bites human handlers.
The leading mechanistic explanation is that selection for tameness results in developmental changes in the neural crest that produce this cascade of features [6].
Because human interaction selected wild canines for tameness, a behavior trait of immature animals, we also unintentionally selected for other puppy - like characteristics.
Belyaev observed that as these wild foxes were selectively bred for tameness over several generations, other characteristics changed profoundly too.
To bolster this perspective, Bradshaw and Nott went on: «Studies on foxes selected over 20 generations for tameness by a group of Soviet biologists showed that over successive generations the foxes gradually began to sound more and more like dogs.»
The Guggenheim deserves part of the blame for the tameness.
Humans may have selected animals for tameness (left column), with those choices leading to unintended features seen in many domesticated species (right column).
A breeding experiment with wild red jungle fowl, the precursor to the domesticated chicken, may help explain whether selecting for tameness is the triggering event of domestication and all its characteristics.
Previous studies on foxes [7] and rats [8,9] have shown that strong selection for tameness can be associated with the peculiar phenotypic changes that are typical for domesticated animals.
They compared six foxes selectively bred for tameness and six foxes selectively bred for aggression.
«If confirmed, our finding could help explain why tame foxes are not stressed so easily as foxes that have not been selected for tameness,» Kukekova said.
Choosing animals for tameness might be selecting for ones that have changes in how their neural crest cells function, the researchers proposed in Genetics in 2014 (SN: 8/23/14, p. 7).
This time, one line of rats was selected for tameness and another selected for aggression.
Over many generations, some scientists propose, humans selected among themselves for tameness.
It is therefore possible that, during selection for tameness, juvenile characteristics were also selected for, including the propensity to bark.»
There was selection for cats that were successful hunters and scavengers in built environment and for tameness and affiliative behavior toward humans.