Human ancestor 'Lucy' was hairless, new research suggests. Here's why that matters.

Fifty years ago, scientists discovered a nearly complete fossilized skull and hundreds of pieces of bone of a 3.2-million-year-old female specimen of the genus Australopithecus afarensis, often described as "the mother of us all." During a celebration following her discovery, she was named "Lucy," after the Beatles song "Lucy in the Sky with Diamonds."

Though Lucy has solved some evolutionary riddles, her appearance remains an ancestral secret.

Popular renderings dress her in thick, reddish-brown fur, with her face, hands, feet and breasts peeking out of denser thickets.

This hairy picture of Lucy, it turns out, might be wrong.

Technological advancements in genetic analysis suggest that Lucy may have been naked, or at least much more thinly veiled.

According to the coevolutionary tale of humans and their lice, our immediate ancestors lost most of their body fur 3 to 4 million years ago and did not don clothing until 83,000 to 170,000 years ago.

That means that for over 2.5 million years, early humans and their ancestors were simply naked.