What has lots of legs and glows in the dark? A bioluminescent millipede of course, our Halloween pet!
Bioluminescence, the ability to give off light, happens when chemical energy is converted into light. It can be found in a surprisingly vast array of living organisms. Everybody is familiar with the common firefly, but there are so many more kinds of glowing creatures with different methods for emitting light. Scientists estimate bioluminescence evolved independently more than 40 times!
Today, KTS kids got to know the evolutionary history of the Motyxia genus, the only millipedes that can glow in the dark.
The Motyxia millipedes live in the Sierra Nevada, California, where it is very hot and dry. They are active and night, when it's cooler, and produce a deadly toxin that make them poisonous to their prey. Scientists had thought that the ability to glow originally evolved in these millipedes to warn predators of their toxicity. But recent studies show that their bioluminescence was originally related to the millipedes' harsh environment and not to their predators. It was their body's response to heat stress!
When the temperature climbs up, these millipedes can't use the oxygen they breathe very efficiently and end up accumulating harmful byproducts of their metabolism. But the chemical reactions that make the millipedes light up also produce molecules that neutralize those harmful byproducts. As it turns out, bioluminescence first evolved as a detox method! In more recent evolutionary times, however, the capacity to glow acquired a different function, communication. It's like a sign that says "Don't eat me! You'll die!"
Our little Halloween party
We had some snacks, we prepared for trick-or-treating and ...
... we got gooey with some glow-in-the-dark putty slime!
Happy Halloween!
