In most respects, chimpanzees are physically superior to humans. Pound for pound, they are perhaps four times stronger. They are faster. They can run straight up a tree, climb and swing with an agility that is the envy of an Olympic gymnast.
But ask a chimp to throw a 145-kph fastball over home plate — something even the average Major Leaguer can do — and the chimp is a chump. Chimps can throw only about 30 kph, a speed a Little Leaguer would laugh at, and their accuracy is pathetic.
The reason for the difference is anatomical — the result of critical physical changes in the shoulder, arm and torso of the species Homo erectus that first appeared 2 million years ago, a team of scientists suggested Wednesday in the journal Nature. These adaptations allow the storage and rapid release of the elastic energy that powers the arms of flame-throwing hurlers, such as the Washington Nationals' Stephen Strasburg.