The 3.2-million-year-old fossil, discovered 50 years ago, is considered to be one of the most significant early hominin specimens.

The thinking of early theorists was that our evolution was a coordinated, linear process. Our ancestors’ brains grew steadily larger as they started walking on two legs and standing taller until they became modern human — Homo sapiens.

She was, for a while, the oldest known member of the human family. Fifty years after the discovery of Lucy in Ethiopia, the remarkable remains continue to yield theories and questions.

Paleontologists unearthed the iconic fossil in 1974. Today, her legacy remains just as much cultural as it is scientific.