Natural Selection
...hey can survive in their habitat. The first type of natural selection is directional selection. Directional selection shifts the frequency of one of more traits in a particular direction (Tobin and Dusheck). This happens when a species in resistant to a certain element in its environment. An example is the breeding of the grey hound dog. They wanted the fastest dog, so they bred fast dogs, and then of their offspring used the fastest dogs to breed between them. This was used when greyhounds were used to hunt game.(Hartzog). Next is Stabilizing selection tends to act against extremes in the phenotype, so that the average is favored (Tobin and Dusheck). The Siberian Husky’s main purpose is working in the snow. It is a medium size dog. They have strong pectoral and leg muscles which allows ...