Chapter 16. GENES AND VARIATION. 16.1 - Variation of Traits in a Population (gene pool). Population: all the members of the same species that live in a particular location at the same time and have the potential to interbreed.
GENES AND VARIATION
Variations in genotype arise throughmutation,
-no mutations-no migrations-large populations-random mating-no selection of alleles
favors those individuals who have extreme variations in traits within a population. A useful example can be found in the breeding of the greyhound dog. Early breeders were interested in dog with the greatest speed. They carefully selected from a group of hounds those who ran the fastest. From their offspring, the greyhound breeders again selected those dogs who ran the fastest. By continuing this selection for those dogs who ran faster than most of the hound dog population, they gradually produced a dog who could run up to 64km/h (40mph).
The Abert squirrel inhabits the Coconino Plateau, just to the south of the Grand Canyon, and what is called the Kaibab squirrel inhabits the Kaibab Plateau, just to the north of the Grand Canyon. The Grand Canyon, 200 miles long, 5,000 feet deep, and 12 to 15 miles across, with the Colorado River running through it, acts as a barrier to terrestrial animal movement.
2 important types
1) adaptive radiation
2) artificial selection