Believe it or not, there is an established human world record for the fastest 100 meters running on all fours. The Usain Bolt of four-limb running is Kenichi Ito from Japan, who holds the world record with a time of 15.71 seconds (compared with Bolt’s 9.58 seconds running bipedally). Just as it is somewhat striking to see a nonhuman great ape amble around on two legs, it makes you do a double take to see a human sprinting down the track using all four limbs.* It also stresses, in a very visual way, the notion that our quadrupedal past is, in fact, not so very deep in the past.
