Commonly known as the Grizzly bear, the Ursus Arctos is one of the most interesting but common animals in the world. Even though most Grizzly bears are brown, they can be all the way from white to black! The average weight for a male grizzly bear is 600 pounds but the heaviest ever recorded is 1,600 pounds!
- Kingdom- Anamalia
- Phylum- Chordata
- Class- Mammalia
- Order- Carnivora
- Family- Ursidae
- Genus- Ursus
- Species- U. arctos ssp.
The Grizzly bear first evolved about 700,000 years ago. Grizzly bears can be found in dense forests, subapine meadows, open plains and arctic tundra.
Morphological and Molecular Evidence
- Pinnipeds- An earless seal that looks similar in color to the Grizzly bear and has a similar big body build. The percentages of the corresponding amino acids are 3-5%.
- Canidaes- All canidaes have big broad bodies with fur. The percentages of amino acids is 92%.
- Musteloids- They are similar to pinnipeds and also share the same brown color. The similarities of the amino acids is about 6.5%.
Pinniped- Similar big body build
Canidae- Fury and big bodies
Musteloids- Some are brown and they have big broad bodies
- Dogs- They use their legs and hands the same way bears do.
- Seals- They use their fins just like bears like bears use their arms to swim.
- Pandas- They use their hands to eat and pick up food just as bears do.
A Homologous structure is a part of a structure of something that is similar to another's structure. It's evidence because it shows that animal's body parts are used for some of the same reasons and evolved from each other.
- Thumb- It's not used for anything because all of the other fingers are used to get the fish with their curved fingernails.
Vestigial structures are parts of an animal the that is on them but isn't used or needed for anything. They show evidence of evolution because it shows how things have evolved into not needing certain parts.
- Panda- The fossil part of the head is very alike to the bears.
- Pinniped- This fossil is very different but the ribcage is very alike.
- Dogs- Everything is very alike from dogs to bears with the fossils.
Transitional fossils are fossils of close ancestors of the bear and are evidence for evolution because the fossils look alike.
Young and old bear together simulating the growth and development of a bear.
Comparative embryology is when embrios are really similar which is evidence for evolution because similar embrios mean that an embryo could have evolved from another in a different animal.