Evolution of humans

Question 1

How can we tell if a fossil animal was bipedal?

Answer 1

• The backbone (spine) will meet the foramen magnum directly under the skull.
• Broad hipbones giving a basin-shaped pelvis where the socket locks at a 90 degree angle as it supports the body organs above the pelvis.
• The femur is straight.
• Knees are directly under the pelvis.
• Human foot is arched and the big toe is parallel with others.

Question 2

How can we tell the size of the brain?

Answer 2

We can estimate the size of the brain by finding the volume inside the skull. This is called the cranial capacity. To measure it, you pour sand into the foramen magnum and then pour the sand into a measuring cylinder. The volume of the sand collected is an estimate of the volume of the brain that was held within the skull.

Question 3

How can we tell what food it ate?

Answer 3

• Teeth with thick enamel are adapted to eat hard foods.
• Animals with large jaws and bony crests on skulls would have had strong jaws with powerful muscles to move them = tough and fibrous food.
• Ape jaws are U-shaped but humans are parabolic.