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Compare and contrast selective breeding and natural selection?

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Rose77 | eNoter

Posted November 12, 2013 at 6:58 PM via web

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Compare and contrast selective breeding and natural selection?

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priwork | High School Teacher | eNoter

Posted November 12, 2013 at 10:47 PM (Answer #1)

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Natural selection term given by Charles Darwin is natural process by which biological traits become either more or less common in a population because of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment. It is a key mechanism of evolution.
 
While Selective breeding (also called artificial selection or Unnatural selection) is the process by which humans breed other animals and plants for particular traits.
 
 
Example of natural selection :-
1-In an ecosystem, some giraffes have long necks and others have short ones. If something caused low-lying shrubs to die out, the giraffes with short necks would not get enough food. After a few generations, the giraffes would have long necks.
 
2- Peacock females pick their mate according to the male’s tail. The ones with the largest and brightest tails mate more often. Today, males that do not have bright feathers are very rare. 
 
Example of selective breeding :-
1-Producing disease-resistant wheat by crossbreeding wheat plants with disease resistance and wheat plants with a high yield.
2-Increasing milk yield by selecting bulls from high yield herds and breeding them with cows that have the best milk production.
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caledon | High School Teacher | (Level 2) Educator

Posted November 13, 2013 at 12:23 AM (Answer #2)

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Pri1003 is entirely correct.

One of the points that bears emphasis here is the fact that "selective breeding" is entirely unique to, and confined, to humans, and is responsible for everything from modern agriculture to the range of size in domesticated dogs.

The process itself, and its results, can be viewed in the link I've attached to a Youtube video on the Russian efforts to domesticate foxes.

In general, I prefer to call selective breeding "artificial breeding" because it clearly establishes that this is not a process driven by nature, but by humans. We might think that animals which breed based on cosmetics, such as bright plumage or staged combat, are participating in selective breeding, but this is referred to specifically as sexual selection. There is some debate over whether humans have become a sexually selective species in modern times. In contrast to artificial selection, however, sexual selection is still considered an aspect of natural selection.

We must also be careful never to assume that the "direction" that humans build into their artificial breeding, such as seeking high-productivity crops or docile animals, is present within natural selection.

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