BIOL 321 Chapter Notes - Chapter 2: Selective Breeding, Genetic Variation, Hearing Dog
1 Aug 2017
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Artificial selection: process of humans deliberately choosing certain varieties of an organism over others by implementing breeding programs that favor one variety over another. In each generation they allow only the tamest to breed and become parents for the subsequent generations: this artificial selection has produced foxes that can be held and petted by humans and who also seek out human contact. When nature is the selective agent traits including behavioural traits will incr. or decr. in frequency as a function of how well they suit organisms to their environment. If one trait helps to increase the fitness of indivdiuals and if the trait can be passed down across generations then natural selection will operate to increase the frequency of the trait overtime. Fitness of advanatage of as low as 1% per generation is sufficieint for one behavior to replace another over evolutionary time. Over evolutionary time small differences in fitness can accumulate into large changes in gene frequencies.
