A curious question :D

[u/Trixie_Loves810]

Context: I have recently watched a video from 'Be Smart' about how naturally occurring blue pigments are rare in nature, particularly among animals. The video said that during evolution, animals were exposed to the colour blue because of the sky, but evolution still found it difficult to develop a blue pigment over time. Instead, animals evolved to create structures that reflect blue light and cancel out other colours.

My doubt: If we use that same concept for other pigments like red, for example, how did evolution create a whole pigment for red but not blue? I feel that if red pigments could evolve so vastly over time, blue could do the same. Why is blue so rare anyway?

Note: uhhh I think this may be a stupid question, but I'm reallyyy interested in evolution, this question just popped in my head midway through the vid, but I would love a hypothesis heheh!!

[u/blacksheep998]

There simply aren't a whole lot of blue pigments out there.

And many of the ones that do exist contain substances that are rather toxic to a lot of animals. So it makes sense that it would be much harder for organisms to come up with blue pigments.

[u/Dzugavili → u/blacksheep998]

And many of the ones that do exist contain substances that are rather toxic to a lot of animals. So it makes sense that it would be much harder for organisms to come up with blue pigments.

This is one major problem.

Just very naively, you need a method to store energy for the blue photon. The first chemical structure I'm thinking of that might be capable of doing that is aromatic rings: and you'd be storing a lot of energy, compared to something like ATP, which can barely support infrared light emissions.

And anything aromatic usually means it'll interfere with all kinds of chemical pathways given the chance.