Corals can see
It was too tempting not to get one. Imagine during the course of evolution, to have so many photons in the environment, regulated on a cyclical plan, with a trillion fold difference in photon emission rates from day to night. Imagine all that available light and then imagine a species that could survive without any ability to detect light or its absence. It would surely be an evolutionary crime. Most animals of which I am aware, that were once thought to be blind, turn out to have some form of light detection. Even bacteria, such as halobacteria have the same rhodopsin in their membranes that we have in our eyes to detect light: they just do something a little different with the signal (they use it to make ATP). Light and sound provide us with the great distance receptors talked about by the Nobel laureate Lord Adrian. Vision allows every animal to detect images that are far away so that protective or survival mechanisms can be implemented long before the threat arrives. But the cyclical nature of light, from the noon day sun to the darkest shimmer of a moon, also provides a means for timing, and timing for some things, like reproductive behavior in an ocean that dilutes eggs and sperm, can be as critical for survival and propagation of the species as making a timely dash away from a predator. Every year it seems we discover something new driven by light.
Share This
Print This Post