PALEO200 Lecture Notes - Lecture 8: Ornithopod, Extended Family, Vertebra
Document Summary
> dinosaurs evolved from a single common ancestor species. > often incorrect to say that evolution is a random process. while genetic mutations may occur randomly, the evolutionary process that weeds out disadvantageous mutations and favours advantageous mutations is a selective process. > ankylosaurs, euoplocephalus, ceratopsian, triceratops and all of the hadrosaurs have a predentary bone. the ankylosaur and certatopsian dont have the broad beak of the hardosaurs. > a group of species that share a common ancestor is called a clade. Independently: convergent evolution happens when animals are under similar selective pressures maybe its the environment that they live in, or the food they eat. > can recognize convergent features if look at the anatomy easy to see birds, bats and pterosaurs have different wing structures. But anatomical distinction is not easy to see when think about moles, moles and golden moles were though for a long time to belong to the same clade of mammals