On November 24, 1974—50 years ago this November—a pair of paleoanthropologists made the discovery of a lifetime: a set of 47 bones, hidden in the dusty, rocky hills of a fossil site in Hadar, Ethiopia. The skeleton belonged to a 3.2 million year old hominin, which came to be nicknamed Lucy.

She marked the very first specimen of Australopithecus afarensis—a species of early hominins that were very likely our own ancestors. Lucy might be the most famous fossil in the world, and she’s transformed our understanding of human evolution.

SciFri’s Kathleen Davis looks back at 50 years of Lucy with the people who know her best: Dr. Donald Johanson, founding director of the Institute of Human Origins at Arizona State University and the paleo legend who discovered her, as well as Dr. Zeray Alemseged, paleoanthropologist at the University of Chicago who discovered “Lucy’s baby.” They discuss what Lucy has taught us in the last 50 years, why she remains a scientific icon, and how understanding our ancestral origins helps us understand humanity.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

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