Artificial selection

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==The process==
 
==The process==
Artificial selection starts with the raw material found in nature.  People find some animal, plant, or fungus that is in some way [[delicious]] or useful (as in a strong but relatively docile animal), and first simply use it as it is.  Then if it is observed that some specimens are tastier or more useful, the key step is to figure out ways to breed them in captivity.  Otherwise, the result of ''natural'' selection, as we keep eating the tastier ones, will be selective pressure ''reducing'' the "delicious" gene in the wild population.  Once breeding chosen indivduals can be achieved, a domestic stock has essentially been produced.  This stock can then be further selectively bred for the desired traits.  Wild examples can still be brought into the captive gene pool if needed.
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Artificial selection starts with the raw material found in nature.  People find some animal, plant, or fungus that is in some way [[Goat|delicious]] or useful (as in a strong but relatively docile animal), and first simply use it as it is.  Then if it is observed that some specimens are tastier or more useful, the key step is to figure out ways to breed them in captivity.  Otherwise, the result of ''natural'' selection, as we keep eating the tastier ones, will be selective pressure ''reducing'' the "delicious" gene in the wild population.  Once breeding chosen individuals can be achieved, a domestic stock has essentially been produced.  This stock can then be further selectively bred for the desired traits.  Wild examples can still be brought into the captive gene pool if needed.
  
 
==Line breeding==
 
==Line breeding==

Revision as of 23:51, 15 October 2007

Artificial selection is the method of carefully breeding plants or animals to suit human purposes better than they did as found in nature.

Thus, as natural selection depends on genetic variation and competitive pressures, artificial selection depends on genetic variation and man-made pressure - culling unwanted examples and enforced breeding between examples with desired traits. It is important to note that not all traits are susceptible to artificial selection. This is especially true for complex traits such as intelligence.

Virtually all of our foodstuffs, work and companion animals, and ornamental plants are the result of (in some cases) thousands of years of artificial selection.

The phrase "selective breeding" is synonymous with artifical selection.

The process

Artificial selection starts with the raw material found in nature. People find some animal, plant, or fungus that is in some way delicious or useful (as in a strong but relatively docile animal), and first simply use it as it is. Then if it is observed that some specimens are tastier or more useful, the key step is to figure out ways to breed them in captivity. Otherwise, the result of natural selection, as we keep eating the tastier ones, will be selective pressure reducing the "delicious" gene in the wild population. Once breeding chosen individuals can be achieved, a domestic stock has essentially been produced. This stock can then be further selectively bred for the desired traits. Wild examples can still be brought into the captive gene pool if needed.

Line breeding

Often, a trait will turn up, in nature or captivity, that is desireable but very rare (or even unique). In order to build a domestic population showing this trait, the critters will be bred with their own offspring, increasing the frequency of the genes responsible for the trait. Since after a few generations of this undesireable recessive traits may begin to accumulate as well, wild or at least unrelated individuals will be bred back into the stock. After many generations of this process, sustainable populations in which the trait is "fixed" (all individuals are homozygous for it) will be created.

See also

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