primates bio 2215 oklahoma city community college dennis anderson
TRANSCRIPT
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Order Primates
• Opposable thumb• Binocular vision• Fingernails usually• Mammary glands
reduced to one thoracic pair
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Hominid
• Bipedal• Weight bearing pelvis• Loss of opposable toe• Flattened face• Enlarged frontal lob
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Animal Connection
• Humans share many traits with animals
• We are most similar to apes– Same 206 bones
– All but 3 of 650 muscles the same
– DNA is 98% the same
– Same blood typesAlbino Gorilla
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Why are we so similar to apes?
• Modern apes and modern man share a common ancestor who lived about 7 million years ago
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Sequence of Human Evolution
• Hundreds of fossils have been found
• Some of the major fossils will be discussed in this presentation
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Australopithecus afarensis
• 3.5 million years ago• Nicknamed Lucy• Walked upright• Small brain• Skeleton human like
– Feet– Pelvis– Upright stance
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Comparative Anatomy
• Gorilla pelvis adapted for knuckle walking• Human pelvis adapted for upright walking• Lucy’s pelvis very similar to human pelvis
Lucy
Human
Gorilla
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Fossilized Footprints
• Footprints left when a a pair of Australopithecines walked in the ash of a recently erupted volcano
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Skull Anatomy
• Thick brow ridges like a chimpanzee• Cranial capacity 400 cc. Chimp 350 cc.• Teeth similar to human teeth
Chimp
Lucy
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Lucy: A Transitional Fossil
• Transitional fossil shows characteristics of two kinds of animals– Represent the transition from
one organism to another
• Ape characteristics– Skull– Cranial capacity
• Human characteristics– Walked upright– Feet– Pelvis
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Homo habilis
• Cranial capacity 630 cc• Flatter face than
Australopithecines• Used tools
– Nicknamed handy man
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Homo erectus
• 1.8 million to 35,000 years ago
• 1,000 cc cranial capacity• Large brow ridges• Sloping forehead• More advanced tools than
H. habilis
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Homo erectus
• Skeleton very similar to modern man
• Used fire• Traveled
– Fossils found in Africa, Europe, China, Indonesia
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Homo neanderthalensis
• 200,000 to 25,000 years ago
• Cranial capacity up to 1750 cc– Larger than modern man
• No chin
• Sloping forehead
• Buried dead with tools and flowers
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Neanderthal Man
• Mitochondrial DNA studies indicate he was not a direct human ancestor
• Contemporary species with early Homo sapiens
• H. sapiens out competed H. neaderthalensis
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Homo sapiens
• 200,000 years ago to present– Photo is a skull 35,000
years old
• 1400 cc cranial capacity
• Vertical forehead• Pronounced chin
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Sequence of Human EvolutionOne of several possibilities
Common ancestor
Homo sapiens
Modern apes
Australopithecus afarensis
Australopithecus africanus
Homo habilis
Homo erectus
Homo neanderthalensis
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Evolution of Skull
• Cranial capacity increases for a larger brain• Face become flatter• Brow ridges become smaller• Forehead becomes higher• Chin develops
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Sahelanthropus tchadensis
• 6 to 7 million years ago• Flat face like Homo• Cranial capacity about the
same as a chimp• Walked upright