Many marine creatures, including sea worms, some jellyfish, and sea pickles, can emit a magical glow through a process called bioluminescence.The evolutionary origin of this is The production of light remains a mysteryBut an international team of scientists suggests that bioluminescence may have first evolved in a group of marine invertebrates called octocorals at least 540 million years ago, or nearly 300 million years earlier than previously believed. I discovered that there is. This new timeline could help scientists unravel the origin story of bioluminescence. For more information on the survey results, please visit The study was published April 23 in the journal Proceedings of the Royal Society B.
What is bioluminescence?
bioluminescent organisms Produce light through chemical reactions.This ability evolved independently at least 94 times in nature. Bioluminescence is involved in a variety of animal behaviors, including communication, courtship, camouflage, and hunting. fireflies, glowworms, and even some types of fungi Those on land are also considered bioluminescent organisms.
“No one really knows why it evolved in animals first,” says study co-author Andrea Quattrini, curator of corals at the Smithsonian Institution’s Museum of Natural History. stated in a statement.
The earliest example of bioluminescence in animals is Approximately 267 million years ago Until this new study turns back the clock, it was discovered in ostracods, small marine crustaceans known for their synchronized, slime-filled mating dances.
Evolutionary tree of 88 corals
inside studythe research team traced back the evolutionary history of octocorals, looking for clues to when they first appeared in animals. double coral Sea fans, sea pens, and soft corals are a group of living animals that have been frequently bioluminescent since ancient times. Like hard corals, double corals are small colony-like polyps that build reef structure, but they are primarily soft-bodied and not stony. Glowing double corals usually glow when struck or disturbed. According to the teamwhich makes the exact function of the ability to produce light a bit of a puzzle
[Related: These newly discovered bioluminescent sea worms are named after Japanese folklore.]
“We wanted to understand the timing of the origin of bioluminescence, and octocorals are one of the oldest animal groups on Earth known to be bioluminescent,” said study co-author and Smithsonian National Daniel DeLeo, a postdoctoral researcher at the Natural History Museum. stated in a statement. “So the question is when did they acquire this ability?”
they looked at the details Octoral evolutionary tree constructed in 2022.A map of this evolutionary relationship – or phylogeny– We used genetic data from 185 different octocoral species. The team then placed his two octocoral fossils of known age into the tree based on their physical characteristics. Using the ages of the fossils and their positions on the evolutionary tree, researchers were able to roughly determine when the Yao coral lineage split into two or more branches. The researchers ultimately mapped the evolutionary relationships that characterize all known bioluminescent species alive today.
By labeling this evolutionary tree and the branches containing bioluminescent species, the research team used a statistical method called . Reconstruction of the ancestral nation Analyze relationships between species.
“If we know that these species of eight-row corals living today are bioluminescent, we can use statistics to infer whether their ancestors were likely to be bioluminescent. ” Quattrini said. “The more living species that have a characteristic in common, the more likely their ancestors had that characteristic as well, if you go back in time.”
Several different statistical methods all reached the same result. Approximately 540 million years ago, The common ancestor of all octocorals was very likely bioluminescent. This is about 273 million years earlier than in ostracod crustaceans, which were previously thought to be the earliest examples of bioluminescence in animals.
According to the team, the thousands of extant species of octocorals and the relatively high incidence of bioluminescence suggest that luminescence played a role in the evolutionary success of this group. While this doesn’t answer exactly what Yagi corals use bioluminescence for, the fact that this has been retailed for so long does demonstrate how important this form of communication is to their survival. It shows whether
Conservation impact
The research team knows that the common ancestor of all octocorals may have already produced its own internal glow, so they set out to more thoroughly count which of them are present. I’m interested. There are over 3,000 known species in this group. Although they are still bioluminescent, they have lost their properties over time. This may allow us to pinpoint the set of ecological conditions that correlate with bioluminescence and shed light on its function.
The team is also working on Create a genetic test Determining whether eight coral species have a functional copy of the gene luciferase–Enzymes involved in bioluminescence. Future research may even find that bioluminescence is even older and integrated into corals’ evolutionary history.
[Related: Surprise! These sea cucumbers glow.]
The study also points to evolutionary insights that may help monitor and manage octocorals in today’s oceans. They are currently threatened by mineral extraction, fishing, oil and gas extraction and spills, and anthropogenic climate change.
National Oceanic and Atmospheric Administration (NOAA) recently confirmed The Earth is currently experiencing its fourth global coral bleaching event on record, and the second in the past decade due to heat stress caused by continued ocean warming. Double corals can bleach This is what hard corals can do in extreme temperatures. Understanding more about how they use bioluminescence could help scientists better identify their habitats and monitor their behavior. Better knowledge about their genetics and what they need to survive could also inform better conservation policies for these marine creatures.
