The Evolution of Bioluminescence

Back in the Day…

Bioluminescence is certainly an interesting phenomenon, but it is believed that this chemical reaction was not originally used for the purposes of firefly communication. Luciferin is the starting component in the luminescence reaction, and is housed in the peroxisomes of the light-producing cells. However, some experiments and cladistics studies suggest that luciferin may have served initially as a cell antioxidant, acting as a “scavenger” that consumes toxic, oxygen-derived compounds produced by normal cellular reactions and protecting the cell from oxidative stress.

Evidence for Luciferin as a Cell Antioxidant:

Bioluminescence reactions have independently appeared more than 30 times during evolution. This suggests that light-producing systems are not that difficult to develop, and that light production may have evolved later in time.
Photocytes (the light-producing cells) are packed with tracheal terminals and mitochondria, indicating that the bioluminescence reaction is coupled with oxygen metabolism.

(Edited Image from Microsoft Powerpoint.)

Various marine animals utilize a luciferin “analog” called coelenterazine, which is proven to serve as a cell antioxidant.
Studies indicate that luciferin inhibits acellular lipid peroxidation.
Presently, the luciferin reaction is catalyzed by the enzyme luciferase; however, these two components were likely independent in earlier times. As a result, the luciferin reaction was considered “dark”, meaning that no light production would have been apparent (Dubuisson et al. 2004).