It now appears that the lowly worm, Caenorhabditis elegans, has evolved a new sensory perception heretofore unknown to science. In the current issue of PLoS Biology, Stacey L. Edwards, Kenneth G. Miller, and others have shown that these nematodes can detect ultraviolet light using receptors completely unlike any other light receptive molecule in visual systems. In fact, this receptor (cleverly called LITE-1) is more similar to taste receptors in worms and in flies than pigment molecules in other visual systems. It remains unclear how the ultraviolet signal is transduced through the worms receptor to activate the worms’ nerves, however they have eliminated the possibility that it is only heat that they the worms sense. Regardless, it seems that evolution has again demonstrated the cooption of an existing system (in this case – taste), to create an entirely new system (UV sensing).
This serves as yet another example of a peephole into reality that should make us envious of our animal brethren. So let us add “tasting” light to the list, which now contains pit viper infrared, electroception of fishes, magnetoception of birds, and echolocation of bats and cetaceans.