Apes to Man

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Apes to Man
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Human Evolution

• Human evolution is characterized by several types
  of changes in phenotype Note obviously, these
  aren't the only phenotypic changes characteristic
  of the human species, but are more noteworthy in
  regards to human evolution.

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Changes in brain size skull shape

• Smaller to larger brain capacity
• Spinal insertion moves from rear to base of skull

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Comparative Brain Sizes
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Hand Shape

• Development of more flexible opposable thumb
• Allowed advanced tool use

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Pelvis shape

• Allowed early hominids to stand walk upright
• Gave advantage of being able to see around them
  on the savannah

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Spine Shape

• Changed from "C" shape to "S" shape

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Jaw Size

• Jaw has reduced in size, reflecting changes in
  species diet
• Size of teeth have generally decreased,
  especially canines

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Hominid changes over time
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Timeline of human ancestry

• 14-16 Million Years to (?) - Ramapithecus
  Proconsul
• Earliest Ape-like ancestor.
• Did not walk upright
• Similar in size to the chimpanzee, but stockier

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Genus Australopithecus

• 3.5 - 1 million years - Genus Australopithecus
• Several Species of this genus including
• A. afarensis, A.africanus, A. boeisi
• Earliest is Australopithecus afarensis
• Very much apelike with an important feature. Was
  able to walk upright

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Australopithicenes
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Australopithicenes
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Homo Habilis

• 2 - 1.5 million years - Homo habilis "handy
  man".
• Larger than Australopithecus
• Larger brain
• Was first to use stone tools.

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Homo habilis
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Homo habilis contd.
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Homo erectus

• 1.5 Million years - 80,000 years . Homo
  erectus.
• Larger than H. habilis
• Larger brain
• Smaller face
• Was the first to use fire
• Allowed man to "break out" of Africa into Europe
  Asia

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Homo erectus
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Homo neanderthalis

• 130,000 - 30,000 years. Homo neanderthalis
  "Neanderthal man"
• Probably not a direct ancestor - but another
  offshoot from H. erectus
• Shorter, stockier, stronger than modern man.
  Adapted to ice age.
• Larger brain size than modern man.
• Buried dead with flowers - first evidence of
  religeous/symbolic thinking.

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H. neanderthalis
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Modern man

• 100,000 years to present - Homo sapiens (modern
  man).
• Appears to have originated from H. erectus in
  Africa, then migrated outwards to Europe Asia.
• Replaced existing species H. erectus H.
  neanderthalis

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Radiation theory of H. sapien evolution
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Parallel theory of H. sapien evolution
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Current phylogeny of H. sapiens
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How to make a human

• Millions of years ago, a majority of northern
  Africa was rainforest. Ancestors to man
  Rapapithecus and Proconsul, were full arboreal
  apes living in these forests.

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Changes

• However, approx. 5 mya the great rift valley
  formed in east central Africa.

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Problems..

• The effect of this rift was to
• Isolate the ape population from their peers in
  the west.
• The rift also created a rainshadow desert to
  its leeward side.

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Change of environment.

• This change in precipitation changed the
  landscape of the region from rainforest to
  savannah. The apes needed to develop a new form
  of transportation since they could no longer
  brachiate through the trees. Thus, they evolved
  the ability to walk upright.