Models on WHY?

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Models on WHY?

• Why we became bipedal (6 hypotheses)
• Efficient bipedalism as the primary form of
  locomotion is seen only in hominins.

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Origins of all these bipedalism tendencies?
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Primate Evolution

• Where all the humans, australopithicines,
  monkeys, apes, homo habilis, tarsiers, lorises,
  bush babies, Neandertals, hobbit humans, etc.
  came from
• Millions of years ago right after the dinosaurs
  died

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The end of the Cretaceous period 65.5 mya
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Paleocene 65 myaPlacental mammal radiation

• Earliest primates

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Eocene 55-35mya

• More than 200 recognized fossil primate species.

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Eocene 55-35 mya

• More than 200 recognized fossil species.

Darwinius, from the Messel site in Germany,
discovered in 2009 and dates to 47 mya.
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Eocene Primates

• Foramen magnum position whether the body is
  habitually horizontal (like a horse) or vertical
  (like a monkey). 
• During the Eocene, the foramen magnum in some
  primate species was beginning to move from the
  back of the skull towards the center.
• SuggestingHolding their bodies erect while
  hopping and sitting, like modern lemurs, galagos,
  and tarsiers.

Eocene Era primate and modern human skulls
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Oligocene

• Rafting Africa-gt South America 34 mya early in
  the Oligocene
• By this early point in the Oligocene, continental
  drift had separated the New World from the Old
  World.
• New and Old World monkeys branch off here, 35
  million years ago.

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Oligocene

• Approximate position of the continents during the
  beginning of the Oligocene

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Oligocene Primates from Fayum

• Apidium
• Primitive dental arrangement suggests near or
  before evolutionary divergence of Old and New
  World anthropoids
• Small, squirrel-like fruit and seed eating, adept
  at leaping and springing

Walking with the Beasts (BBC) Whale Killer
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Egypts Fayum

• Today, its a 550 square mile lush oasis basin
  in the desert south of Cairo
• During the Eocene and Oligocene, the Faiyum was
  forrested
• At the beginning of the Miocene, the Faiyum had
  become a dry hollow

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Oligocene Primates from Fayum cont.

• Aegyptopithecus (genus)
• 35-33 mya
• Largest of Fayum anthropoids, roughly the size of
  a modern howler monkey (13-18 lbs)
• Short-limbed, slow-moving