Researchers have established a precise timeline for when luminescent traits first appeared in life on land, tracing the moment when organisms began emitting light through chemical reactions. The findings were published in a prominent scientific journal and contribute a clearer picture of how bioluminescence emerged across the evolutionary record.
Bioluminescence is not a single invention but a trait that evolved independently many times, arising in diverse lineages to serve purposes such as camouflage, mating displays, signaling, and predation. This repeated emergence highlights how useful light emission can be in complex ecosystems and how different organisms have harnessed chemistry to interact with their surroundings.
Before this work, scientists believed the earliest terrestrial glow originated around 267 million years ago in a group of small marine crustaceans known as ostracods. The new research pushes the origin much further back, placing the first detectable glow no later than 540 million years ago. The initial champions of bioluminescence were marine invertebrates called octocorals, which form colonies built from soft, flexible structures. When stressed or threatened, many organisms in this group respond with light emission, a countermeasure and communication tool rolled into one.
To reconstruct this history, researchers integrated genetic data with evolutionary models, tracing the lineage of modern octocorals back toward their ancient roots. Employing multiple statistical approaches, they concluded that the common ancestor of present-day octocorals most likely possessed bioluminescent capabilities, suggesting that the glow is a deeply rooted feature in this lineage rather than a later adaptation.
The implications extend beyond dating a unique trait. By illuminating the emergence of bioluminescence, the study enhances understanding of broader evolutionary patterns, including how sensory and signaling systems evolve in response to ecological pressures. The discoveries offer insight into how life on Earth has diversified its methods of communication and interaction through light, shaping the dynamics of ancient marine communities and the subsequent terrestrial lineages that followed.
Overall, the new timeline not only reframes the origin story of natural light production but also provides a clearer window into the processes by which evolutionary innovations arise, spread, and persist across deep time. The glow observed in contemporary coral reefs and other bioluminescent systems is thus part of a long, shared history that began hundreds of millions of years ago and continues to influence life today.