Chapter 32-3: Primates & Human Origins Essential Questions: What characteristics are shared by all primates? What are the major evolutionary groups of primates? What is a hominid? What does the fossil record show about hominids?
What is a primate? Fingers, toes & shoulders 5 flexible fingers, flexible toes, shoulders allow arms to rotate Most have opposable thumbs
Well-developed cerebrum Allows complex behavior – social behaviors, adoption, warfare
“Brain Capacity”
Binocular vision, flat face Able to merge images from 2 eyes Depth perception 3D view
Evolution of primates Prosimians – earliest branch Lemurs, lorises
Anthropoids – humans, apes, most monkeys 2 branches caused by separation of continents New world monkeys (Central/South America) – adapted for trees; have prehensile tail Old world monkeys (Africa/Asia) – baboons, orangutans, gorillas, chimps, humans
What is a hominid? About 6 m.y.a.: hominid line gave rise to humans Bipedal – 2 feet locomotion – skeleton changed for this Early hominids Australopithecus – “Lucy” fossil; probably ancestral to humans How do the branches connect? No simple, straight-line transformation from early hominids to modern humans
Skulls
Skulls
Out of Africa – but who and when? Modern Homo sapiens Homo neanderthalensis – Europe & N. Asia; 200-300 thousand years ago Stone tools, organized groups
Species
Homo sapiens – appear in Spain about 400 thousand years ago cave paintings, burial rituals Only hominid species left on earth