Glow-Worms Get a Leg Up

SCIENCE

Scientists think they’ve cracked the mystery of why some millipedes developed their glow. (Nat Geo Kids)

Let our encyclopedic entry illuminate the process of bioluminescence!

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit—and don’t forget to take this week’s Nat Geo News Quiz!

Discussion Ideas

 

  • According to our encyclopedic entry, bioluminescence is usually a defensive adaptation, an offensive adaptation, or an adaptation for attraction. What type of adaptation have the California millipedes developed?
    • It’s a defensive adaptation. Millipedes light up to warn predators they are toxic. (Special glands produce cyanide—the brighter the glow, the more cyanide produced.)

 

 

  • How did bioluminescence help millipedes adapt to the hot, arid climate of the Sierra Nevada foothills?
    • According to Nat Geo News, “millipedes have trouble metabolizing oxygen when it’s really hot, which creates chemical byproducts such as peroxide. The bioluminescent proteins help neutralize these byproducts and prevent harm to the millipede.”

 

These images show two species of bioluminescent millipedes: M. sequoiae (A and B) and M. bistipita (C and D). Photograph courtesy Paul Marek, Virginia Tech, and the Proceedings of the National Academy of Sciences

These images show two species of bioluminescent millipedes: M. sequoiae (A and B) and M. bistipita (C and D).
Photograph courtesy Paul Marek, Virginia Tech, and the Proceedings of the National Academy of Sciences

  • Extra Credit: Researchers found that “bioluminescence—the ability to give off light—may have first developed not to fend off enemies, but to help [millipedes] deal with California’s hot, dry environment,” and “the warmer the environment, the dimmer the millipedes glow.” Of the two species of millipede above, which species do you think lives in a warmer environment? Which species do you think is an newer branch of the millipede family tree? Which species do you think is more toxic?
    • Warmer climate: M. bistipita, on the right, lives in warmer climates. The chemicals in bioluminescent proteins help it cope with the heat.
    • Younger species: M. sequoiae, on the left, is a newer branch on the millipede family tree. It evolved after M. bistipita, using already-developed bioluminescence to help fend off predators.
    • More toxic: M. sequoiae, which has more predators than M. bistipita, also contains more cyanide.

 

TEACHERS’ TOOLKIT

Nat Geo: Glowing Millipedes Revealed

Nat Geo: New Glowing Millipede Found; Shows How Bioluminescence Evolved

Nat Geo: What is bioluminescence?

Nat Geo: What is an adaptation?

(extra credit!) Proceedings of the National Academy of Sciences of the United States of America: Discovery of a glowing millipede in California and the gradual evolution of bioluminescence in Diplopoda

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