Lucy

Nearly half a century ago, in the rugged landscapes of Hadar, Ethiopia, American paleoanthropologist Donald Johanson and French geologist Maurice Taieb stumbled upon a groundbreaking find: the 3.2-million-year-old skeleton of Lucy, a primitive hominin with a small brain and the ability to walk upright, much like modern humans. Known scientifically as AL 288-1, Lucy represents one of the most significant discoveries in understanding human ancestry.

Johanson and Taieb, while mapping and surveying for fossils in the area’s ancient sediments, first came across a hominin forearm bone. This initial find led to a two-week excavation, unearthing hundreds of bone fragments that comprised 40 percent of a single hominin skeleton. That evening, celebrating their discovery, the team named the fossil Lucy, inspired by the Beatles’ song “Lucy in the Sky with Diamonds,” which echoed in the background as they reveled in their success. Remarkably intact for its age, Lucy’s discovery was a rare stroke of luck, as fossils of this era are often irreparably damaged.

Lucy was considerably smaller than modern humans, standing about 3.5 feet (1.07 meters) tall, with an ape-like face and a brain roughly a third the size of today’s human brain. Her stature indicates she was female, and subsequent fossil discoveries revealed significant size differences between male and female members of her species.

A defining trait of all hominins, including Lucy, is bipedal locomotion. Her anatomy, particularly her angled distal femur, large knee joints, and curved spine, was well-suited for upright walking and standing.

Following Lucy’s discovery, over thirteen more hominin individuals were found at Hadar, collectively known as the “First Family.” These findings established Lucy as part of a previously unknown hominin species, Australopithecus afarensis. This species consisted of small-bodied and small-brained early hominins capable of upright walking but not suited for long-distance ground travel.

The australopith group, to which A. afarensis belongs, likely gave rise to the later hominin groups Homo and Paranthropus before 2.5 million years ago. While A. afarensis was not the first discovered member of its group—that distinction goes to A. africanus from South Africa—its discovery confirmed that habitual upright walking occurred early in human evolution, well before the development of larger brains.

Upright walking likely offered survival advantages, such as earlier predator detection and freeing the hands for tasks like carrying food and using tools. Fossils suggest that A. afarensis lived between 3.7 and 3 million years ago, surviving for over 700,000 years—more than double the timespan of Homo sapiens.

Currently, Lucy’s fossil resides at the National Museum of Ethiopia in Addis Ababa, Ethiopia, where she is known as Dinkinesh, meaning “you are marvelous.”