BIOL 3040 Chapter : Evolution Chapter 3 4
Document Summary
Treehopper has a helmet structure on their backs that help camouflage them from predators. They don"t have a 3rd wing on their thoracic segment, they have this helmet structure. Their genes don"t code for wings they code for these helmets. They don"t have the wings that the original insects had, instead they have these novel structures (the helmets). Exaptation: a trait that serves on purpose today, but evolved under different selection conditions and served a different function in the past. Mammalian have live birds, so the sutures in the skull of mammal babies are soft so that the baby skull can compress to fit out. However reptiles and birds have sutures too but they are born from an egg, so they have this for a different reason. It is said that they have these sutures so that their brain can grow and expand. Feathers arose in dinosaurs to serve as insulation or signals, sexual selection.
