Why are the faces of primates (and people!) so dramatically different from one another?
Biologists working as "evolutionary detectives" studied the faces of 129 adult male primates from Central and South America in search of some answers, and discovered that faces they studied evolved over at least 24 million years.
Science Daily quotes evolutionary biologist Michael Alfaro as saying, "If you look at New World primates, you’re immediately struck by the rich diversity of faces. You see bright red faces, moustaches, hair tufts and much more. There are unanswered questions about how faces evolve and what factors explain the evolution of facial features. We’re very visually oriented, and we get a lot of information from the face."