B. Both cats have sophisticated, sleek, and retractable claws used for hunting they both also have rear teeth called carnassial teeth. These teeth are designed for tearing meat or other food before swallowing. Both of these qualities were inherited from their feline ancestors whom also had these traits. However, Mountain Lions use these traits more aggressively because they are wild. Mountain Lions' prey includes deer and smaller animals such as porcupines and coyotes and their teeth and claws are considerably bigger than that of a house cat's. They also have an extra toe and claw (a total of 5) on each of their front paws compared to the house cat (only 4 on every paw) and this is so they can easily clutch prey. Mountain Lions' front paws and claws are larger on their front legs than they are on their back legs which is also attributed to grasping prey while a house cat's paws and claws are generally all the same size. A house cat's diet usually consists of man-made cat food therefore they don't need the two inch canines like a Mountain Lion. Each feline has similar design in their teeth and claws, the main difference being the size, of course, because of the difference in prey. Mountain Lions need a stronger jaw in order to carry prey bigger than them.
C. The first common ancestor of these felines is the Proailurus that lived approximately twenty-five million years ago. Proailurus was a small animal, a bit larger than the house cat, that also had sharp claws and teeth with the same uses as modern cats. This species is said to have given rise to the major felid lines. There's also the Pseudaelurus which was also similar in size to domestic cats and was the first felid to reach North America however it descended from the Proailurus.
2) A. Both Polar Bears and Snow Leopards have thick fur for insulation, coloring similar to the snow, and wide feet that act as natural snow shoes. Both species have these traits in order to survive their extreme weather conditions.
B. Polar Bears and Snow Leopards have paws covered in fur in order to bear roaming the snow ridden ground and to protect their paws on any type of cold surface. Both animals have thick, thick fur for insulation in order to keep them warm because of the cold climates they reside in. Snow Leopards have very strong, powerful legs that allow them to leap as far as fifty feet. Polar bears also have very powerful legs but they use their power for swimming long distances. A Snow Leopard has grey fur to blend in with it's surroundings which looks similar to the white coat of the Polar Bear that also uses it for camouflage against the snow and ice, however the Snow Leopard has black spots on it to help blend in more to it's specific environment.
C. All carnivorans evolved in North America from the same family, Miacidae. The animals in this family were carnivores like Polar Bears and Snow Leopards so they had similar traits attributed to hunting. However, I couldn't find anything on that group of carnivores that lived in climates as cold as or specifically similar to Polar Bears and Snow Leopards so they might not have had the traits specific to these animals climates such as fur on the bottom of their paws or thick fur for isolation.
Your homologous traits worried me at first as they come dangerously close to be shared traits, but you did carefully explain the differences that exist in the physical structure of the traits and back that up with an explanation of the different environmental pressures that produced those differences. The only caution is rooted in the origin of the domesticated cat, which seems to have arisen in Egypt. Did that ancestor still have the 5 toes? Or had they lost the toe already? That would confirm whether or not it was the "environment of domestication" that produced that trait. Something to think about but it won't impact you here.
ReplyDeleteGood description for your analogous traits.
Miacidae existed a long time ago and its descendents dispersed globally long before the lines that brought us the polar bear and the snow leopard developed. It doesn't come into play here. Understanding the specific evolution of the two species tells us more about why these traits are analogous. The snow leopard evolved more recently in Asia and moved into the colder clines during that process, so we know that its cold weather traits developed independently. Likewise, knowing the evolutionary history of bears, we know the polar bear's cold weather traits are derived recently, independently. These are analogous traits.
Delaney,
ReplyDeleteGood job on your blog. I was really interested in reading about your analogous paragraph. I liked the pictures and reading about the snow lepards and polar bears having fur to go with the weather.