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 hide caption

itoggle caption T.L. Kivell & M. Skinner

Bonobos at the Lola ya Bonobo sanctuary in the Democratic Republic of Congo. Courtesy of Vanessa Woods hide caption

itoggle caption Courtesy of Vanessa Woods