Evolution of Bipedalism

When do we first see evidence of bipedalism in the hominin fossil record?

• 6 mya

• 2 mya

• 10,000 ya

• 1 mya

Select ALL of the fossil evidence that could indicate bipedalism:

• Central foramen magnum

• Forward facing big toe

• C-shaped spine

• Long arms compared to leg length

Select ALL of the fossil evidence that suggests a species is still arboreal (lives in trees):

• Large scapula (shoulder bones)

• Long curved fingers

• Opposable big toes

• 45 degree valgus angle

Which of these is likely the FIRST reason why we started to evolve bipedalism:

• Thermoregulation in the hot climate

• Efficient walking between sparse trees

• Better reach to collect food

Which happened first: climate change in Africa (became warm hot savannah) or evolution of bipedalism?

• Bipedalism

• Climate change

Which of these are advantages of bipedalism? Select ALL correct answers.

• Hands free to gather more food

• Hands free to use tools

• Efficient movement

• Easy childbirth

As climate became hot and dry which of these features of bipedalism became advantages?

• Able to see predators over long grass

• Hands free to carry more food

• Less surface area exposed to the sun

• More surface area exposed to horizontal wind/breeze

Which of these best describes the postural feeding hypothesis?

• Bipedalism allows hominins to cool down faster

• Bipedalism allows hominins to reach up and collect more food

• Bipedalism is more efficient for moving quickly between trees

• Bipedalism allows hominins to carry their young safely

Which type of natural selection drove the evolution of bipedalism?

• Directional selection

• Disruptive selection

• Stabilizing selection

Which form of primate locomotion is more energy efficient?

• Qudrupedal knuckle walking

• Opportunistic bipedalism

• Habitual bipedalism