Photosynthesis

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Outline

• Evolution of Primates
• Mobile Limbs
• Binocular Vision
• Evolution of Early Hominids
• Evolution of Later Hominids
• Evolution of Early Homo
• Modern Humans
• Human Variation

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Evolution of Primates

• The evolution of primates is characterized by
  trends towards
• Mobile limbs
• Grasping hands
• A flattened face
• Binocular vision
• A large, complex brain, and
• A reduced reproductive rate

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Primate Diversity
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Mobile Limbs

• Hands and feet
• Most primates have flat nails
• Sensitive pads on the undersides of fingers and
  toes
• Many also have both an opposable big toe and
  thumb
• Mobile limbs and clawless opposable digits allow
  primates to freely grasp and release tree limbs

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Evolution of Primate Hand
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Binocular Vision

• Stereoscopic vision
• Depth perception
• Allows primates to make accurate judgments about
  distance and position of adjoining tree limbs

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Binocular Vision
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Primate Characteristics

• Opposable thumb
• Nails instead of claws
• Single births
• Binocular vision
• Expanded, complex brain
• Emphasis on learned behavior

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Evolution of Primates

• Prosimians were the first type of primate to
  diverge from the human line
• Surviving anthropoids are classified into three
  superfamilies
• New World monkeys
• Old World monkeys
• Hominoids

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Evolution of primates
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Evolution of Hominids

• Proconsul is believed ancestral to hominids
• Phylogenetic tree indicates humans are most
  closely related to African apes
• Genetic changes used as a molecular clock to
  measure relatedness of different groups
• Last common ancestor appears to have lived about
  7 mya

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Monkey SkeletonCompared to Proconsul Skeleton
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Hominids

• Hominid fossils
• Must have an anatomy suitable for standing erect
  and walking on two feet
• Bipedalism
• Skeletal differences between humans and apes
  largely because
• Humans are bipedal, while
• Apes are quadrupedal

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Adaptations for Standing
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Australopithecines

• Australopithecines
• Evolved and diversified in Africa 4 mya
• Possibly a direct ancestor of humans
• Southern Africa
• Australopithecus africanus
• Eastern Africa
• Australopithecus afarensis

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Human Evolution
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Australopithecus afarensis
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Evolution of Early Homo

• Homo habilis
• Dated between 20 an 19 mya
• May be ancestral to modern humans
• Skulls suggest portions of the brain associated
  with speech were enlarged
• Ability to speak may have led to hunting
  cooperatively and the advent of culture

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Homo erectus

• Homo erectus and similar fossils
• Found in Africa, Asia, and Europe
• Dated between 19 and 03 mya
• Larger brain and flatter face than Homo habilis
• Much taller than previous hominids
• Thought to have first appeared in Africa and then
  migrated into Asia and Europe
• First hominid to use fire

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Homo ergaster
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Evolution of Modern Humans

• Most researchers believe Homo sapiens evolved
  from Homo erectus
• Multiregional Continuity Hypothesis
• Similar evolution occurred in many different
  places
• Out-of-Africa Hypothesis
• H. sapiens evolved from H. erectus only in
  Africa, and thereafter migrated to Europe

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Evolution of Modern Humans
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Neanderthals

• Neanderthal (H. neanderthalensis) skeletons were
  first discovered in Germanys Neander Valley
• Skeletons date back 200,000 years
• Massive brow ridges with protruding nose, jaws,
  and teeth
• Heavily muscled
• Culturally advanced
• Manufactured variety of tools

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Neandertals
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Cro-Magnons

• Oldest fossils to be designated H. sapiens
• Modern humans who entered Asia and Europe from
  Africa 100,000 years ago
• Made advanced stone tools
• Accomplished hunters
• Hunted cooperatively
• First to have language

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Cro-Magnons
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Human Variation

• Hypothesized that human variations evolved as
  adaptations to local environmental conditions
• Bergmanns Rule - Animals in colder regions of
  their range have a bulkier body build
• Allens Rule - Animals in colder regions of their
  range have shorter limbs, digits, and ears
• Comparative study of mitochondrial DNA
• Suggests human populations have a common ancestor
  no more than a million years ago

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Ethnic Groups
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Review

• Evolution of Primates
• Mobile Limbs
• Binocular Vision
• Evolution of Early Hominids
• Evolution of Later Hominids
• Evolution of Early Homo
• Modern Humans
• Human Variation

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