Lucy

"Lucy" (Australopithecus afarensis) reconstruction by Gary Sawyer

Perhaps the most familiar of all early hominids, "Lucy" lived in eastern Africa more than three million years ago. Members of her species, Australopithecus afarensis, ventured down from the trees and into the grassy woodlands along the edges of forests, where they walked on two limbs instead of four. Studies of this skeleton have shown that Lucy and her kind walked upright, like modern humans. But their cone-shaped rib cages, short legs and small brains resembled those of apes.

"Lucy" skeleton (Australopithecus afarensis)

Examine the Evidence: Primate skeletons

long fingers and toes are good for climbing trees
short legs are helpful for moving around in trees
wide and short pelvis suggests upright posture
thigh bones angle in toward knees, making upright walking easier

One of the Family

Discovered by scientists in 1974, this early hominid was named after the Beatles' song "Lucy in the Sky with Diamonds," which the researchers listened to as they celebrated on the night of their remarkable find.

Pelvis/bipedalism comparison of Lucy (center) with chimp (left), human (right)

Inside the Bones

The pattern covering the walls of this hall is based on a digital image of Lucy's bone tissue. This picture was made using confocal scanning microscopy, a technology that allows scientists to "see" microscopic details inside fossils without cutting and damaging them. The sets of concentric circles, the largest of which are the width of a human hair, contained a blood vessel in life. Images like this help show how bone structure and function have changed in the course of human evolution.