12.6 primate evolution how did modern humans evolve?

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12.6 Primate Evolution 12.6 Primate Evolution How did modern humans evolve?

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Page 1: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

12.6 Primate Evolution

How did modern humans evolve?

Page 2: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

KEY CONCEPT Humans appeared late in Earth’s history.

Page 3: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

Humans share a common ancestor with other primates.

• Common ancestor of all primates probably arose before the mass extinction that ended the Cretaceous Period.

• Primates are mammals with flexible hands and feet, forward-looking eyes and enlarged brains.

Page 4: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

• Primates evolved into prosimians and anthropoids.

– Prosimians are the oldest living primates.– They are mostly small and nocturnal. (lemurs)

These are the tarsiers. Their physical appearance has changed little since their appearance 40 MYA.

Page 5: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

– They are subdivided into the New World monkeys, Old World monkeys, and hominoids.

– Anthropoids are humanlike primates.

Page 6: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

– New world monkeys are native to the Americas.–Live in trees–Have grasping tails

Page 7: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

– Old world monkeys are native to Africa.– spend some time in trees, but spend much of the time foraging on the ground

- They have larger brains and can grasp things better.

Page 8: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

- Homonoids are divided into hominids, great apes, and lesser apes.

– Homonids include living and extinct humans.

Page 9: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

• Homonids walk upright, have longer lower limbs, opposable thumbs, and large brains

• Include all species in the human

lineage, both modern and extinct.

• The skeletal changes required

to walk upright can be seen in

intermediate fossils between

homonoids.

Page 10: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

• Bipedal means walking on two legs.• Walking upright has

important adaptiveadvantages.– foraging– carrying infants and food– using tools

Page 11: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

There are many fossils of extinct hominids.

• Most hominids are either the genus Australopithecus or Homo.

• Australopithecines were a successful genus.• The Homo genus first evolved 2.4 million years ago.

Page 12: 12.6 Primate Evolution How did modern humans evolve?

12.6 Primate Evolution

Modern humans arose about 100,000 years ago.

• Homo sapiens fossils date to 100,000 years ago in Ethopia.• Human evolution is influenced by a tool-based culture.• There is a trend toward increased brain size in hominids.

Australopithecusafarensis

Homo habilis Homo neanderthalensis

Homo sapiens