C 16- Primate Evolution

Pp. 420-441

Content

• 16-1 Primate Adaptation & Evolution

• 16-2 Human Ancestry

Primate Adaptation & Evolution

• Primates – group of mammals including lemurs, monkeys, apes & humans.

• Common traits – opposable thumbs, binocular vision, large relative brain volume, flexible arms & joints, grasping feet.

Primate Origins

• Strepsirrhines earliest fossils 50 -55 MYA

• Current ex. Lemurs, aye-ayes in Africa & SE Asia

• Typically small, nocturnal animals w/ big eyes

Primate Origins

• Haplorhines – tarsiers & anthropoids such as hominoids including apes & humans, Old & New World monkeys

• More complex brains, more upright posture, different skeletal features.

Primate Origins

• New World Monkeys- 30 -35 MY old fossils• Central & S America• Arboreal with prehensile tail

Primate Origins

• Old World Monkeys• Arboreal or terrestrial

without prehensile tails; includes colobus monkeys, macaques, baboons.

• Adapted to many varied environments from hot, dry savannas to cold mountain forests.

Fossils 20 – 22 MYA

Primate Origins

• Hominoids- apes (orangutans, gibbons, chimpanzees, bonobos, gorillas) or humans

• Lack tails, have long, muscled forelimbs, large brain capacity

• Oldest anthropoid fossils 37 – 40 MYA

Primate Origins

• By examining DNA of modern hominoids, scientists have evaluated the probable order in which apes and humans evolved.

• Chimpanzees share the closest common ancestor w/ humans.

Jane Goodall

16.2 Human Ancestry

• In Africa, 5-8 MYA, a population ancestral to chimpanzees & humans diverged.

• May have been due to environmental changes.

• Bipedal hominids had a survival advantage.

Human Ancestry

• Australopithecus africanus discovered by Raymond Dart 1924 with features of both apes & humans.

• Braincase & facial structure of ape & position of foramen magnum like humans

• 2.5-2.8 MYA

Human Ancestry

• Paleoanthropologist Donald Johanson (1974) “Lucy” Australopithecus afarensis found in E Africa 3-4 MYA

• Although braincase was more like chimp, pelvic bone was more humanlike.

The Emergence of Modern Humans

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• Handy man or Homo habilis

• 1.5 -2.5 MYA

Homo habilis skull

Primate Adaptation & Evolution

• Handy man or Homo habilis

• 1.5 -2.5 MYA• Discovered 1964 by

Louis & Mary Leakey in Olduvai Gorge, Tanzania in Africa

• Earliest known hominid to use tools

Homo habilis

The Emergence of Modern Humans

• Homo erectus 1.5-1.8 MYA “upright human”

• Larger brain, more human face, prominent brow ridges, lower jaw w/ no chin

• Evidence suggests hunters lived in caves Africa, Asia, & Europe

The Emergence of Modern Humans

• H. sapiens 100,000 – 500,000 YA

• Neandertals 35,000 – 100,000YA during ice age, had religious views & spoken language

• Cro Magnon more modern with similar size to humans, toolmakers & artists

Emergence of Modern Humans

• Humans haven’t changed much in past 200,000 years.

• Africa, Europe, Asia, North America

• 10,000-8000 YA native Americans had establish settlements w/ domesticated animals & farming