The Secret of the Human Eyes: How Evolution Shapes our Perceptions

 

 

This post is reproduced from my blog "The Proud Holobionts" where I explore how the new concept of "Holobiont" can find applications not only in biology, but in many fields dealing with complex systems, including the human economy, memetics, and ecosystems

 

 

The short movie abov, Vikaari, has recently appeared on the "Dust" site and I think has several interesting features, relevant to the concept of holobionts. 

 

It is very well done as a movie, although it is deeply contradictory in many aspects. For one thing, it is a narrative disaster. First, the movie tells you that the "Vikaari", children born without a visible iris in the eyes, are good people, while being the target of Nazi-like bad guys. Then, we see the Vikaari killing their pursuers using their psychokinetic powers in bloody and cruel ways, apparently without any regret. Needless to say, this completely destroys the narrative tension of the movie and leaves you totally baffled about what the filmmakers wanted to say.

Indeed, I think the filmmakers were badly confused on several planes. First of all, in their decision of presenting this "new race" of children as something that will replace current human beings, engaged in destroying their own planet. Is this a hope or a fear? Difficult to say, but surely evolution doesn't work in that way. 

And then, why the choice of iris-less eyes as a defining mark? It is rare that people consciously perceive the characteristics of the irises of their fellow human beings. But the shape of the iris tells us much of the genetic inheritance of a person. On this point, the film-makers got it right, although in reverse. A human being without a visible iris is not a modern human.

 

The iris is an easily modified, highly visible human trait. There is a whole genetic story in the human iris. From what we can say, light-colored eyes have been rare in the remote past, although DNA studies indicate that they already existed in the Mesolithic period. Curiously, Europe is the continent where, nowadays, light-colored eyes are most common. But it is only a few centuries ago that light-colored irises start to appear in paintings. If they had existed before, surely painters would have noted them and shown them in their paintings. Green eyes are a modern trait in Europe, they seem to come from Northern Asia. They do spread easily because they are a typical "epigamic" trait. They give a certain advantage in the sexual competition for mates. 

 

And then, there are limbal rings. The dark ring that surrounds the iris. Also a typical epigamic signal, they are likely to be a feature of the modern main organism of the human holobionts. Here you see the eyes of Sarah Brightman, a modern human specimen. Note the light green color and well detectable limbal rings. As epigamic signals go, Ms. Brightman is surely beaming them out loud and clear!

 

Note the difference from other mammalian eyes. Most animals, even our close relatives, the apes, have dark eyes, no limbal rings, and not even a large and well detectable sclera. You see it in the image: this (probably) female bonobo doesn't look at all like Sarah Brightman, although she also surely sends powerful epigamic signals to the males of her species. 

So, why do the Vikaari of the movie have no irises and no pupil? They are, actually, the specular version of the "black eyed people," characters of a recent horror movie. In both cases, filmmakers understood that the lack of sclera or of the iris is a characteristic of a creature that is not fully human. A new species (as in Vikaari) or an otherworldly evil creature (as in "Black Eyed Creatures"). No wonder that regular humans react with great perplexity and sometimes violently to these alien-looking creatures. And this violence is reciprocated in Vikaari. 

The existence of these films shows our limited understanding, and also limited tolerance, of what makes humans human. A small difference in the extent of the sclera or in the color of the iris is sufficient to turn otherwise fully human creatures into enemies, at least in these fiction pieces. But we all know very well that it happens also in the real world for other, no more important genetic traits, such as skin color. 

 

There is a thin line that separates the horrible from the attractive: nobody would be killed for having green eyes, but the white-eyed Vikaari could be if they existed for real. But that's the way evolution works. Sometimes gradually, sometimes in bumps. The human holobiont of the future will not be the same as it is now and it was in the past. It is the giant holobiont that we call the ecosphere that changes all the time. Onward, fellow holobionts!

Finally, for your curiosity, the "Statue of a Standing Nude Goddess," presently at the Louvre Museum and coming from excavations in the Middle East. Note the eyes without irises. It is not clear if that was a bug or a feature: once they had decided to use rubies for the eyes of this statuette, there was no way they could have shown irises and pupils. But maybe it was intentional: this figure may have been supposed to be somewhat otherworldly or even threatening. Note the horns on her head, a typical attribute of the Moon Goddess. Already at the time when it was made, probably the 2nd century CE, goddesses were rather unpopular and suspicious, not unlike our modern witches.