RP315 The Soft Glow of the Natural World

 RP315 The Soft Glow of the Natural World

Whether it's fireflies glowing in the night sky or an angler fish illuminating the darkest depths of the ocean, bioluminescence shows us just how clever the process of evolution can be.
The word bioluminescence comes from a combination of the Greek word for living and the Latin word for light. It's used to describe the light that certain organisms can produce via a simple chemical reaction involving luciferin, luciferase, and oxygen.
Most people assume that bioluminescence is restricted to fireflies and glowworms, but in reality several organisms can glow in the dark, including fish, whales, squids, bacteria, and even mushrooms. Bioluminescence also comes in a whole spectrum of colors, from the black dragonfish's red glow to the way Vibionaceae bacteria can make the ocean look like milk.
So what's the point of all this glowing? The answer has to do with evolution. Each species has evolved bioluminescence in order to survive in its environment.
Take fireflies for example, their bioluminescence serves a few purposes. It helps them attract things they want such as prey and potential mates. It also helps them avoid potential dangers. Predators think twice about eating fireflies because they know that the chemicals that produce bioluminescence taste awful.
Firefly bioluminescence is fairly straightforward. Other species can be a lot more complex. Mycena lucentipes, a glowing mushroom found in Brazil, is one such example. Insects are a constant threat to these mushrooms, so they rely on bioluminescence to attract animals that like to chow down on insects. This is like evolution's version of the old saying "the enemy of my enemy is my friend."
Comb jellies have also evolved a fascinating defense. If a predator takes a bite out of these bioluminescent deepwater jellyfish, their meal will continue to glow all the way into their stomach. This illuminates the predator, which can be quite dangerous in the darkness of the ocean. Consequently, predators think twice about bothering comb jellies in the future.
The process of evolution is truly amazing. It's like nature's tycoon—it identifies a gap in the market and uses innovation to fill it. What's more, if evolution can find a way to make living organisms create light like a light bulb, what can't it do?