Apparently, cuttlefish are colour-blind. So, how does this master of camouflage manage to generate such a variety of exotic and dynamic patterns, including the capacity to blend into any background against which it finds itself? If the cuttlefish eye can’t discriminate between the different wavelengths in the visible spectrum, then how can it work out the colour signals to send to its kaleidoscopic skin, if it doesn’t ‘know’ what colour is? Amazing, eh? And we don’t know how it does it.
So, I think about bats, which aren’t blind at all. It is difficult for us to comprehend, but, presumably, their echo system, rather than light, is processed by their brains to produce a perfectly sufficient three-dimensional imaged construction of their world. It’s the brain that sees; the sense organs merely transduce the incoming energy into a signal with which the brain can work.
The cuttlefish makes me think of our new Zeiss Observer. Z1 microscope (uh-oh, product placement; I’ll be donning pin-stripes next). For capturing colour fluorescent images, this scope employs a black and white camera. The colours are applied to the image by the computer, as specified by the user according to the selected excitation wavelength filters. Might not something similar be at work in the cuttlefish brain? Perhaps it selects its own built-in excitation filters according to something subtle in the ‘black-and-white’ image its huge eyes transduce to the brain. Which is easier for evolution to craft: colour-receptive ocular apparatus; or a brain that can synthesise colour and apply it accurately? I think of how old B & W films are restored and colour treated; but this requires some prior knowledge of what colour is. The cuttlefish has never seen colour. So maybe it senses something we can’t. Maybe it ‘sees’ emotion, and reacts emotionally. Or maybe it employs some other sense, of which we cannot perceive.
Moreover, this beautiful creature doesn’t leave apple cores on buses; doesn’t use mobile phones in restaurants; doesn’t vituperate in public. That’s not to say it wouldn’t if it could.