Polar Bear evolution

Divergent Evolution Evolution is the theory of organisms changing over time. The first two people to explore this theory were Charles Darwin and Alfred Russell Wallace. There are four types of evolution, those being adaptive, convergent, divergent, and co-evolution. Divergent evolution is when two or more animals originate from a common genetic base. To prove divergent evolution in animals, the Ursus Maritimus or polar bear is an example. Divergent evolution is when similar animals branch off becoming dissimilar as time goes. Divergent evolution occurred 125,000 years ago when brown bears were isolated from their ancestors. This movement got them stranded and trapped by glacial ice and happened because of geographic isolation which is being separated by natural surroundings.(See figure 2) When this happened, natural selection kicked in and provided stronger animals to live in the environment. The brown bears that survived breaded and evolved into the polar bear. With this divergent evolution, the bears had caused speciation.(Pbs.org,2008) Adaptation also occurred to the bears after they had evolved. Some of the adaptation were related to its teeth, fur, and etc. When the brown bear evolved into Polar bears, they slowly received the dominance of white fur instead of the brown fur based on their environment. (Pbs.org,2008) They received this trait because it was beneficial to them in order to camouflage and withstand the cold temperatures. Another adaptation is when bears didn't require hibernation because they had no use for it. They only hibernated if they have a dearth amount of food or if a female bear was in the process of pregnancy. An additional trait acquired was the growth and sharpness in their teeth.(See Figure 1) Their teeth help them catch their prey and helped them fight their foes. The traits acquired helped them because they made it easier to live in their environment proving evolution. The common ancestor of divergent evolution is an