With the help of researcher Sabudo Boraru (right), anthropologist Chris Campisano, of Arizona State University, takes samples from the fossil-filled Ledi-Geraru project area in Ethiopia. The jawbone was found nearby.
Courtesy of J Ramón Arrowsmith
An example of a human precision grip — grasping a first metacarpal from the thumb of a specimen of Australopithecus africanus that's thought to be 2 to 3 million years old.
T.L. Kivell & M. Skinner
Rocky Juarez of the U.S. gets punched in the face in July 2010 by Jorge Linares of Venezuela during their WBA Fedelatin lightweight title fight in Las Vegas. Some researchers believe the human face evolved to take punches — without, of course, the boxing gloves.