How Fireflies Glow (and What Really Turns Them On)
A new book details the lights, loves, and science of fireflies.
Summertime, and we’re all looking forward to some July 4 fireworks, not to mention some smaller lights in the nighttime sky.
The enzyme that turns on the rainbow of colored lights that occur in different firefly species is called luciferase. Sara Lewis, author of the beautiful new book Silent Sparks: The Wondrous World of Fireflies, says what first hit the switch was really a glitch.
The firefly gene that codes for luciferase is very similar to a common fatty acid-making gene, Lewis says. It's likely a duplicate of that gene acquired a mutation that caused it to produce a tiny bit of light in a distant firefly ancestor. (Related: How Do Fireflies Glow? Mystery Solved After 60 Years).