Too many false alarms in the nervous system when heat is mistaken for light? Here:
“For a long time, people assumed that light and heat had to trigger via different mechanisms, but now we think that both types of energy, in fact, trigger identical changes in the pigment molecules,” says Yau. Moreover, since longer wavelength pigments have higher rates of false alarms, Yau says this may explain why animals never evolved to have infrared-sensing pigments.”Apart from putting to rest a long-standing debate, it’s a wake-up call for researchers to realize that biomolecules in general have more potential thermal energy than previously thought,” says Luo.
– “Why Animals Don’t Have Infrared Vision: Source of the Visual System’s ‘False Alarms’ Discovered”, (ScienceDaily June 9, 2011)
File under: the design of life
Note:: All that said, some snakes do, however, have infrared “vision” – as good as they need it to be.