Blog # 4 Describe the three types of selection: directional, stabilizing and disruptive and give an example of each in your own words

Stabilizing selection favors the norm, the common, average traits in a population. Look at the Siberian Husky, a dog bred for working in the snow. Stabilizing selection has chosen a norm for the the size of the Siberian Husky. Directional selection favors those individuals who have extreme variations in traits within a population. For example people pick hounds that were the fastest in their group, from their offspring the breeders again selected the dogs that ran the fastest. By continuing this selection for those dogs, they gradually produced a dog who could run up to 64km/h (40mph). Disruptive selection, like directional selection, favors the extremes traits in a population. Disruptive selection differs in that sudden changes in the environment creates a sudden forces favoring that extreme. Think about the changes in the environment when that meteor crashed into Earth 65mya. If a plague started by the high death rate also hit these stressed animals, they would have been sorely pushed to survive. Evidence shows that they did not. So disruptive selection occurs quickly, selecting for those extreme traits that help organisms survive in the new environmental conditions.