1.A.2 Continued

One example of an evolutionary change that is partially related to a change in the environment is the emergence of dog breeds over hundreds of years. It has been impacted by both environmental as well as human factors. From the environmental standpoint, the regions from which certain breeds emerged played some part into what physical characteristics canines adapted. For example, the dense, thick fur of the Siberian Husky allowed it to endure the extremely cold and harsh climates of the Siberian Arctic. The Mexican Hairless Dog is a breed whose lack of hair allows it to be comfortable in the Central American heat. The role of humans has played a very large impact on the evolutionary change in these animals. When we bred ancient dogs for certain tasks, they developed characteristics suited to those tasks over many, many generations. For example, the muscular, compact body of the Portuguese Water Dog allowed it to herd fish into nets, retrieve tackle, and serve as courier from boat to land. Our actions in this respect were artificial selection. While dog breeds will continue to change and emerge, similar developments may be seen in similar species in the future. Domestication of foxes in recent years has notably resulted in foxes with dog-like traits such as less erect tails.