What purpose could algae have to glow in the dark?
I means, they have no eyes and they cant profit from it? from a predatory stand point it might as well signal grazer to come feast? Which is not very useful.
In my fantasy world, I have phytoplankton that are glowing during the nights. What would drive evolution to produce glowing algae, that glow every nights and all night long, on a alien planet?
Thanks for you input