Did Humans Evolve? Comparing Hominid Skulls By: Jenny Kong

Smart Start  Brainstorm a list of characteristics that humans and chimpanzees share in common. What do you infer based on these common characteristics?

Video 5: Did Humans Evolve?  Describe the fossil evidence that supports the evolution of humans from earlier primate ancestors.  Explain how DNA sequences are used to provide evidence of common ancestry.

Brain Case Size  Measure the width – with the calipers (ruler) on the sides (temples) of the skull at the widest point  Measure the length – with the calipers (ruler) at the most forward point of the forehead and the most posterior point at the back of the skull

Position of Brain  Is the brain positioned on top of the eyes or behind the eyes?

Walk on 2 legs or 4 legs?  Observe the large opening in the base of the skull through which the spinal cord passes. The position of this hole reflects the body posture of a hominoid.  Is the hole located: –toward the rear/back (4 legs), or –more forward/bottom (2 legs)

Forehead or Browridge  Look for a bony ridge protruding (sticking out) over the eyes. –If it is pronounced (obviously visible)  Browridge –If it is not really visible  Forehead

Face Sticks Out or Flat  Do the chin and mouth stick out (almost like a dog’s snout) or is it flat?

Age of Skull  Chimpanzee: present  Cro-magnon Man: 35,000 years ago  Homo sapien: present  Neanderthal Man: 130,000 – 30,000 y.a.  Homo erectus: 2.0 –.5 million y.a.  Australopithecus boisei: 2.0 – 1.1 m.y.a  Australopithecus afarensis: 4.0 – 3.0 m.y.a.