Animals started glowing in the dark nearly 300 million years earlier than we thought

Bioluminescence in marine life dates back 540 million years, winding back the clock by a staggering 300 million years against earlier estimates, a new study finds.

"We often think that the deep sea is light-limited, and this is true in terms of sunlight, but many organisms in the deep sea produce their own light through a simple chemical reaction known as bioluminescence," study author Andrea Quattrini, curator of corals at the Smithsonian's National Museum of Natural History, told Live Science in an email.

Bioluminescence — or glowing in the dark — is abundant in marine life including in fish, corals, jellyfish and crustaceans. On land, the phenomenon is found in many Animals, including fireflies, beetles, mushrooms, algae and some bacteria.

Scientists believe that life evolved bioluminescence to aid in communication, courtship, predation, and as a means of camouflage.

Uncovering similarities in genetic sequences across groups can provide clues about the evolutionary history of a trait or characteristic. Bioluminescence involves a highly heritable protein called luciferase and, so far, the phenomenon is thought to have evolved around 100 times.

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In a new study published Wednesday (April 24) in the journal Proceedings of the Royal Society B: Biological Sciences, scientists reveal the origins of bioluminescence in a group of marine invertebrates known as octocorallia, or octocorals.