The northern white-cheeked gibbon is a critically endangered ape native to China, Vietnam and Laos. Scientists have discovered a new species of gibbon, now extinct, that lived in China as recently as 2,200 years ago.
Joachim S. Müller/Flickr
Rocky spent his first few years raised by people, and is particularly attuned to human speech and behavior, researchers say. But his remarkable ability to learn and match human pitch and common sounds of speech surprised them.
Mark Kaser/Courtesy of Indianapolis Zoo
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
An endangered Sumatran orangutan with a baby clings on tree branches in the forest of Bukit Lawang, part of the vast Leuser National Park, in Indonesia's Sumatra island.
Romeo Gacad/AFP/Getty Images