The Origins Of Bioluminescence In Bioluminescent Millipedes

Entomologist Paul Marek went to a forest near San Luis Obispo, California in the winter of 2013 to look for a genus of bioluminescent millipedes called Motyxia. Not only does this genus glow in the dark, they also shine a bright green hue when they are illuminated with UV light. The Motyxia’s glow is a warning to predators that, when threatened, they ooze toxins like hydrogen cyanide. According to the article, recent research indicates that bioluminescence has not always been the defense mechanism of millipedes. Bioluminescence may have originated from another millipede species known as Xystocheir bistipita. X. bistipita has not been known to be bioluminescence 50 years ago when it was last seen, but his recent discovery, Marek has found that

bistipita represents an older, less evolved version of the trait than the brighter glow of their mountain relatives. The higher elevations of which the species of millipede lives, the brighter their bioluminescence will be. Furthermore, millipedes with brighter glows have larger cyanide glands, which may suggest the brighter bioluminescence the more toxic they are. These discoveries help pave the way to a possible explanation on the evolutionary origins of bioluminescence in millipedes. Over time, the brightness of bioluminescence in millipedes have evolved from the faint glowing Motyxia that live at low elevations to the brighter, more toxic Motyxia at high elevations. This evolution may have occurred because millipedes at high elevations have more predators to ward off so a brighter glow and a greater toxicity is necessary for survival. The millipedes at low elevations, however, don’t have as many predators so they have a low glow with not as much toxic as those who live higher. M. bistipita may not have originally acquired bioluminescence as a defense mechanism but maybe as an adaptation to the dry heat of its habitat before other Motyxia species acquired