Biology 3466B Lecture Notes - Lecture 8: Synapomorphy, Coevolution, Even-Toed Ungulate
18 Oct 2012
School
Department
Course
Professor
Document Summary
The presence of a pulley-shaped astralagus argues that hippos and whales are not closely related because today"s whales don"t have an astragalus. A) is the preferred tree as it takes one less evolutionary step. Artiodactyla hypothesis: whales are related to the ungulates, possibly as the sister group to the artiodactyls. Whale+ hippo hypothesis: whales are the sister group to the hippo. Whales have no ankles so the shape of the whale astraglus as a trait cannot be assessed. Fortunately, some fossil whales have hind limbs, which concludes the wales have some features of the pulley shaped astragalus. Coevolution: the buttiflies: the tastey butterflies try to look like the untastey butterflies so that the birds will not eat them.
