Video : Evolution: Jaw Muscle and Brain Cavity Size - One single individual mutated and we inherited the improvement, a single powerful mutation.
December 23, 2008
It seems we may owe our great intelligence to weak jaw muscles. By shrinking the anchors needed to support strong jaw muscles, our brain cavities may have been freed to grow into its modern shape.
Hansell Stedman at the University of Pennsylvania has discovered by chance the differences in the jaw muscle cells between great apes and humans, and combined this information with fossil shapes and dating to isolate a divergence point, where a single mutation may have led us down the road of increasing intelligence.
A very wonderful clip from the National Geographic documentary, "Human Ape".
Evolution: Jaw Muscle and Brain Cavity Size