BY 124 1st Edition Lecture 13Outline of Last Lecture Chapter 34 (cont.)I. 3 lineages of jawed vertebratesII. Tetrapodsa. Characteristicsb. Class Amphibiac. Class Reptiliad. Class AvesOutline of Current Lecture Chapter 34 (cont.)I. Mammals a. Characteristicsb. 3 groupsc. Order PrimatesII. Humansa. Characteristicsb. Factors that allows for bipedalismc. Phylogenic tree Current LectureChapter 34 (cont.)I. Mammalsa. Characteristicsi. Mammary glandsii. 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 sizev. Good lungsvi. Highly developed Nervous systemvii. 4 chambered heartsviii. Differentiated teethix. Evolved from Synapsid → evolved to therapsidsx. Phylogenically successful but there are less today than there used to bexi. Cenozoic Era – Age of Mammalsxii. 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 ofii. 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 apesii. Characteristics1. All primates possess a claviclea. Allows for free movement/ rotation of arms2. 5 functional digits on each foota. Opposable digits (can touch fingertips together)3. Hands and feet that can grasp4. Nails, not claws5. Sensitive tactile pads on fingers and toes6. Reduced snouts7. Much better vision than other ordersa. Binocular vision (3D)i. Eyes are more central on faceb. Color vision8. Cerebral cortex is larger9. Usually only 2 mammary glands10. Usually only one baby born at a timeiii. Two groups:1. Prosimiansa. Lemurs, tarsiers, 2. Antropoidsa. Came from prosimiansb. Include new and old world monkeys, humans, etci. 1st monkeys evolved in Old Worldii. 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 buttocksiii. Old world monkeys: some are almost totally ground-dwellers, 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 chimps2. Chimps can use tools3. Bonobos are considered the most closely related primates to humansII. Humans i. Humans are mammals that have a large brain and bipedal locomotionii. Did not directly evolve from chimpanzees or bonobos but share a common ancestorb. Belong to Family Hominidae1. Not Homonoid – not a formal grouping. An informal group of great apes and humans2. Hominid (Hominin) – ancestors that are not chimps that are on same phylogenic “line” as humansc. Characteristicsi. Rectangular jaw with large molars and canines went to a U-shaped jaw with smaller teethii. Brain case got bigger and face became flatteriii. Arms got shorteriv. Feet got flat with an archv. Big toe moved in line with other toesvi. Lost opposability in toesvii. Skull in more balanced on top of vertebral viii. Bipedalism (aided by balanced skull, flat feet)d. 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 balanceiii. **1856 – 1st time someone paid attention to difference in humans e. Cranium capacity – the size of the brain cavity can decide the size of the brainf. Phylogenic Treei. Homo habilis – “handy man”1. Made toolsii. Homo erectus – 1. not 1st to stand up right2. 1st to move out of Africa3. Learned to control fire4. 1st species to be thought of as participating in actual wars5. Larger brain capacity (1000 cc)iii. Homo neanderthalensis – cave men1. Thought to not be in our direct “line” now 2. 1st group of people to believe in after lifea. Buried deadiv. Homo sapiens – humans today1. 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
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