— Ouch…. Meuianga, what is this?
— Gosh, what happened to this poor ape?
— Is she wounded? Or is that a tumor growing out of her face?
— Is she turning into an insect?
— No, no… cadets. No. It is one of the habits of the naked apes. They wear these things made of darkened glass….
— But, Meuianga, why would they do that?
— Why do they want to see everything dark?
— They’ll get depressed, come on!
— Well, Cadets, that may be, but there is a logic in everything. If you ask them (I did), the Naked Apes will tell you that they wear those dark screens in order to protect their eyes from sunlight. Which, of course, makes no sense. Their eyes are perfectly adapted to the conditions of sunlight on their planet. Their pupils contract or expand as needed, just as our pupils do. So, it is strange that they themselves don’t know why they are wearing those things. But I do. I told you in a previous lecture that the naked apes use their eyes as a communication tool. These dark panels over their eyes shut down this communication channel.
— Hmmm…. we understand, Meuianga. But why would they want to do that?
— You told us that the red lips are also a secondary sexual signal. This female ape seems to send contradictory signals.
— She does, Cadets. They often communicate by sending contradictory signals. Their females do that all the time. They signal sexual availability and then, at the same time, mask their eyes to avoid signaling sexual ability. I think I am starting to understand the games they play, but I must confess that sometimes I am baffled myself. Their females conduct the mating game in ways that I can’t completely understand. But I suppose they know what they are doing. Let me show you something…
— Aaargh…. Meuianga, take off those things!
— You are scaring us!
— Ah… sorry, Cadets. It is just for fun. Let me take these things off. I make a point of experimenting with the uses and the tools of the naked apes. So, I have also been experimenting with these partially dark screens. I have to tell you that it is horrible. I couldn’t see where I was going and I bumped into something. And my noise is still aching a little. Anyhow, these things are completely useless for creatures like us, who have lateral eyes.
— Oh, yes, Meuianga. Another interesting point. The Apes have forward-pointing eyes. Why that?
— Aren’t they predators like us? I always thought that a good predator needs a wide field of view to locate prey.
— That can be explained, too. We are sprinting predators. We jump when we see prey nearby. And for that we need a wide field of view. But they are endurance predators. They locate their prey at some distance, so they need 3D binocular vision…
— Meuianga, you make our heads spin. What would that “binocular vision” be?
— Ah… dear Cadets, that’s another thing that makes the apes different from us. Let’s just say that they don’t use ultrasound emissions to estimate the distance of prey, as we do. They have a sophisticated system for deriving the distance of an object from the overlap of two slightly different fields of view. But it is a complicated story, and for today I think it is enough. I’ll see you again for another lesson. And may the Federation rule justly and wisely.
— May the Federation rule!