BY 124 1st Edition Lecture 13 Outline of Last Lecture Chapter 34 cont I 3 lineages of jawed vertebrates II Tetrapods a Characteristics b Class Amphibia c Class Reptilia d Class Aves Outline of Current Lecture Chapter 34 cont I II Mammals a Characteristics b 3 groups c Order Primates Humans a Characteristics b Factors that allows for bipedalism c Phylogenic tree Current Lecture Chapter 34 cont I Mammals a Characteristics i Mammary glands ii Hair keratin not the same as the scales that have been present up to this point iii High metabolic rate due to endothermy iv Larger brain than other vertebrates of similar size v Good lungs vi Highly developed Nervous system vii 4 chambered hearts viii Differentiated teeth ix x xi xii Evolved from Synapsid evolved to therapsids Phylogenically successful but there are less today than there used to be Cenozoic Era Age of Mammals Can differentiate between mammals and reptiles by the presence of the three inner ear bones malleus incus and stapes Reptiles only have one stapes b Three groups of mammals i Monotremes egg laying mammals echidna platypus 1 Don t have nipples Basically use a sweat pore that milk comes out of ii Marsupials embryo develops within placenta but completes embryonic development while nursing in maternal pouch called a marsupium kangaroo bandicoot iii Placentals Eutherians placenta feeds baby throughout development up until birth squirrels humans c Order Primates i Humans are part of this order but more specifically part of the ape group 1 Different groups lemurs tarsiers monkeys and apes ii Characteristics 1 All primates possess a clavicle a Allows for free movement rotation of arms 2 5 functional digits on each foot a Opposable digits can touch fingertips together 3 Hands and feet that can grasp 4 Nails not claws 5 Sensitive tactile pads on fingers and toes 6 Reduced snouts 7 Much better vision than other orders a Binocular vision 3D i Eyes are more central on face b Color vision 8 Cerebral cortex is larger 9 Usually only 2 mammary glands 10 Usually only one baby born at a time iii Two groups 1 Prosimians a Lemurs tarsiers 2 Antropoids a Came from prosimians b Include new and old world monkeys humans etc i 1st monkeys evolved in Old World ii New world monkeys are arborial live in trees have a prehensile tail can hang from it two nostrils that open to the side on a flattened nose no bright colored buttocks iii Old world monkeys some are almost totally grounddwellers do not have prehensile tails some don t have tails at all nostrils pointed down iv Apes gibbons chimpanzees gorillas orangutans bonobos 1 Share 99 off genes with chimps 2 Chimps can use tools 3 Bonobos are considered the most closely related primates to humans II Humans b c d e f i Humans are mammals that have a large brain and bipedal locomotion ii Did not directly evolve from chimpanzees or bonobos but share a common ancestor Belong to Family Hominidae 1 Not Homonoid not a formal grouping An informal group of great apes and humans 2 Hominid Hominin ancestors that are not chimps that are on same phylogenic line as humans Characteristics i Rectangular jaw with large molars and canines went to a U shaped jaw with smaller teeth ii Brain case got bigger and face became flatter iii Arms got shorter iv Feet got flat with an arch v Big toe moved in line with other toes vi Lost opposability in toes vii Skull in more balanced on top of vertebral viii Bipedalism aided by balanced skull flat feet Changes that allowed for bipedalism i Shorten pelvis and made more upright apes have forward facing pelvis ii S shape spine to distribute weight and balance iii 1856 1st time someone paid attention to difference in humans Cranium capacity the size of the brain cavity can decide the size of the brain Phylogenic Tree i Homo habilis handy man 1 Made tools ii Homo erectus 1 not 1st to stand up right 2 1st to move out of Africa 3 Learned to control fire 4 1st species to be thought of as participating in actual wars 5 Larger brain capacity 1000 cc iii Homo neanderthalensis cave men 1 Thought to not be in our direct line now 2 1st group of people to believe in after life a Buried dead iv Homo sapiens humans today 1 Can speak 2 Evolved from Homo erectus in Africa 3 When we moved out of Africa we wiped out Homo erectus all over the world END OF TEST 2 MATERIAL