Bioluminescence Is at Least Half a Billion Years Old [Video]

Bioluminescence, the eerie, beautiful phenomena that allows living things to glow, is way more ancient than previously thought, according to a team of researchers that recently studied the ability in octocorals.

Octocorals are not closely related to corals, despite their name. They are a group of marine invertebrates that reside—and glow—in Earth’s oceans. But octocorals have been illuminating the seas for at least 540 million years, according to a study published today in the Proceedings of the Royal Society B.

“Some animals that could detect light evolved during the Cambrian, thus our research hints at the possibility that interactions involving light occurred between octocorals and other species during a time when animals were rapidly diversifying and occupying new niches,” said Andrea Quattrini, a zoologist at the Smithsonian Institution and the study’s senior author, in an email to Gizmodo. “We know now that bioluminescence is a critical form of communication for many animals across the tree of life and particularly for those that occur in …