Transcript Primate Evolution - Byron High School

Ch. 16 - Evolution
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What is a primate
◦ Primate
 Group of mammals that include lemurs, monkeys, apes,
and humans
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Opposable thumbs – allows grasping
Binocular vision – depth perception
Large brain volume – in comparison to body size
Rotating shoulder and arm flexibility
Varying degrees of grasping ability with feet
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Division of primates
◦ Prosimians – small, nocturnal, in tropical forests
 Lemurs, aye-ayes, tarsiers
◦ Anthropoids – human like primates with more
complex brains and a more upright posture
 Monkeys, apes, humans
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Monkeys – divided into two types
◦ New world monkeys
 Found in south central American rainforest
 Have prehensile tail – for grasping
◦ Old world monkeys
 Found in a variety of habitats in Asia and Africa
 Do not have a prehensile tail
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Hominids
◦ Primates that can walk upright on two legs
 5-8 million years ago two lines of hominids diverged
from one common ancestor
 Human line
 African ape line (gorilla and chimpanzees)
◦ Hypothesis based on DNA evidence, there is little
fossil evidence
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Advantage of Bipedal
◦ Speed
◦ Hands free
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Australopithecine – early
hominid that lived in Africa
that possess ape and human
features
◦ Nicknamed “LUCY”
◦ Believed to have walked upright,
but had a small brain
◦ Estimated to have lived 3.5 mya
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Bipedal Fossils
◦ Foramen Magnum
 Hole in the base of the skull for spinal cord
 Indicates upright posture
◦ Broadening of the pelvis allows for stability
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A. afarensis
◦ Disappears from the record about 1mya
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Homo habilis – “handy man”
earliest hominid to leave
evidence of stone usage
◦ Larger brain size
◦ 1.5-2 mya
◦ Found in Africa by Louis and
Mary Leakey
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Homo erectus-“upright
human” – first to use fire
◦ Larger brain size
◦ 1.6 mya
◦ May have hunted
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Homo sapiens – “modern humans”
◦ 100-400 thousand years ago
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Neanderthals – H. sapiens w/ brain size like
“us”
◦ Lived in Europe, Asia, and Middle East
 35-100 thousand years old
 Thick bones and large faces
 Believed to have used spoken language and have
religious veiws
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Cro-Magnon – H. sapien identical to modern
humans in height, skull structure, tooth
structure, and brain size
◦ Tool makers and artists
◦ Used spoken language
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Exact evolutionary relationships are not known