Octocorals Evolved Bioluminescence 540 Million Years Ago, Predating Previous Oldest Example

In a remarkable discovery, new research published in Proceedings of the Royal Society B Biological Sciences has revealed that octocorals evolved the ability to produce their own light through bioluminescence around 540 million years ago. This finding pushes back the earliest known example of bioluminescence in animals by a staggering 273 million years, with the previous record held by ostracods, small marine crustaceans.

The study, led by researchers from the Smithsonian's National Museum of Natural History, used genetic data from 185 octocoral species to construct an evolutionary tree. By analyzing this data, they determined that the common ancestor of all octocorals, which include soft corals, sea fans, and sea pens, was likely bioluminescent during the early Cambrian period. "This suggests that light signaling may have been one of the earliest forms of communication on Earth," said lead author Andrea Quattrini.

Bioluminescence, the production and emission of light by living organisms, has evolved independently at least 94 times throughout the history of life on Earth. It serves various functions such as communication, prey attraction, and camouflage. While the exact purpose of bioluminescence in the ancient octocoral ancestor remains unclear, the researchers believe it may have initially been a byproduct of a biochemical reaction before evolving to serve important ecological roles.

Why this matters: This discovery significantly expands our understanding of the evolutionary history of bioluminescence and indicates that this remarkable trait played a vital role in the success and diversification of early marine life. The study also highlights the importance of octocorals as a model system for investigating the ecology and evolution of bioluminescence in the marine environment.

The findings raise thought-provoking questions about why relatively few of the over 3,000 known octocoral species still possess bioluminescent abilities. "Now we can look at the ecology of these species and try to figure out what are the most important factors that are driving the evolution of this trait and its loss," explained Quattrini. As scientists continue to explore the diversity and evolution of bioluminescent marine life, this study represents a significant milestone in unraveling the mysteries of Earth's early oceans and the creatures that illuminated them.

Key Takeaways

• Octocorals evolved bioluminescence 540 million years ago, 273 million years earlier than previously known.
• Genetic analysis suggests the common ancestor of octocorals was likely bioluminescent during the early Cambrian.
• Bioluminescence may have been an early form of communication in marine life.
• Bioluminescence has evolved independently at least 94 times in the history of life on Earth.
• The study highlights the importance of octocorals in understanding the evolution of bioluminescence in the marine environment.