- Mammals, tree of life distinctions o One major distinction:  Marsupials & monotrems  Eutherian, aka placental (the vast majority) o Edentates: toothless mammals; many of the distinctions are based on teeth o Four major clades of edentates - Primate Shared Characteristics o “primitive body plan”; common arboreal condition [shared among NONprimates]:  long, flexible backbone  short flexible neck  5 fingered clinging hands and feet  many have tails Distinguishing Primate Characteristics - Generalized dental pattern; meaning they diet is not specialized, most are omnivores - Evolution of diet: started adding in small vertebrates, then flowers and other similar things, and the last specialization to develop was eating mature leaves - Still having pentadactyly, but also opposable thumb - Padded digits and palms; nails not claws; one of the earliest developments, evolved for a sense of touch, greater sensitivity (there are some exception) o Flat nails on the thumbs are the only defining feature that all primates have, even for those that are exceptions in that they have claws - Ulna and radius allow for palmar rotation o Allows for swinging from tree to tree - Clavicles unite arms to chest to facilitate hanging - Forward facing eyes; this allows for depth perception and 3D vision; improvements in acuity and tri-color color vision o Greater definition in vision led to a lesser reliance on olfaction, reduction of snout as well - Skull expansion and increased brain complexity; also leads to longer gestation period - Longer dependency period and juvenility; mothers therefore carry fewer young - Male residency—both sexes residing together throughout the year, not just during a breeding period o Increased social compl