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Human Evolution. Chapter 19. Early Primates - Prosimians. Lived in trees (arboreal) Exhibits brachiation (swinging from tree to tree) Opposable toes and thumbs Short snout Eyes set close together. Anthropoids. Includes monkeys, apes, and humans.
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Human Evolution Chapter 19
Early Primates - Prosimians • Lived in trees (arboreal) • Exhibits brachiation (swinging from tree to tree) • Opposable toes and thumbs • Short snout • Eyes set close together
Anthropoids • Includes monkeys, apes, and humans. • Old World Monkeys = from Africa & Asia; ground-dwelling & arboreal. • New World Monkeys = the Americas; all arboreal. • Fig 19.1 E
Apes - Tropical Areas of Asia & Africa • Includes gibbons, orangutan, gorilla, & chimpanzee • Have larger brain to body size ratio than monkeys • Flexible Behavior • Several levels of Social organization
Chimpanzee Behavior • Use of simple tools (“termite fishing rod”) • Raiding of social groupings • Ability to communicate with sign language. • Concept of self (Ex: using a mirror) • DNA difference with humans < 3%.
Humanity Fig. 19.3 • Humans and apes diverged from a common ape-like ancestor ~5-7 mya. 5 Main Features: • 1) Increased brain size • 2) Shorter jaws / flatter faces • 3) Bipedal posture • 4) Reduced size diff. b/t male & female • 5) Family structural change
Classifications • Hominoids – includes great apes & humans • Hominids – species of humans (6 mya) • 1) Australopithecines (All extinct) • 2) Genus Homo (All extinct except Homo sapiens)
Walking Upright with a Big Brain • Evidence of footprints found in volcanic ash in Tanzania (E. Africa) • Mary Leakey(1978) & Lucy (3 myo) • A. afarensis skeletal remains found (australopithecine) • Oldest “human” fossil A. anamensis (4 myo)
Humanity on the Move • Homo habilus – use of tools • Homo erectus – taller & larger brain than Homo habilus. • 1st hominid to immigrate to Asia and Europe ~ 1.8 mya • Lived in caves, huts, built fires, wore clothes made of animal skins, & used elaborate tools.
Human Diversification • Multiregional Hypothesis – modern human races stem from regional diversity & interbreeding amongst neighboring populations. • “Out of Africa” / Replacement hypothesis* – 2nd major migration out of Africa. These individuals replaced all the regional populations of 1st migration [100 tya]
Genetic Evidence of Humanity • Comparison of mtDNA & nDNA amongst samples of human populations. • Identified human divergence around 100 tya*. • Isolated & Sequenced DNA from Neanderthals [Europe: 200- 40 tya] • DNA was diff. from modern human DNA.
Genetic Evidence of Humanity • Comparison of Y chromosomes throughout generations b/c no crossing over for Y during meiosis. • Mutations = markers for tracing ancestry. • Identified divergence from common African ancestor < 100 tya*.
Highlights of Human Evolution • Upright posture • Enlargement of Brain • Prolonged period of parental care. • Culture = accumulated knowledge, customs, beliefs, art, & other products. • Transmitted via language, (spoken & written)
Stages of Human Culture • 1) Scavenging-Hunting-Gathering • Scavenging ~100 tya; • ~50 tya tool making developed to allow hunting practices. • 2) Agriculture • Occurred ~10-15 tya • Fertile Crescent (N. Africa -> Israel, Iraq) • Emergence of cities
Stages of Human Culture • 3) Use of Machinery • Industrial Revolution (18th century England) • Reliance on fossil fuel as sources of energy. • Migration to cities; advances in medicine spurred on by increased disease.