Vestigial Organs?

exactly, and not just believe it but understand it and understand why.They both have hair, a trait found in most mammals. You and I probably have different hair but somewhere down the line we're related too (although sometimes i'd like to deny it. . . jk). We're more closely related than sheep and pigs and so logically our hair is more similar.Pigs and sheep are also both warm blooded, give live birth, have mammary glands, and three inner ear bones. These are all traits of mammals. As pointed out earlier, they are also both even toed ungulates supporting the majority of their weight on the third and fourth toes. They also have very similar ankle structure: a two pulley motion allowing for a great deal of flexibility. They ARE related.Fetal pigs, sheep and cats are some of the primary subjects of student dissection and inspection. The reason: they are mammals and are thus closely related to humans in many of their internal structures. We can learn a lot about humans by inspecting the inner workings of other mammals. Of course we could learn more about humans by dissecting humans but a lot of times that is frowned upon. Apes and monkeys are not common to dissect because they tend to be endangered and not commonly bred in mass as livestock. So, we pick some more distant relatives but still mammals.