Eyes made their first appearance, like so many humanoid features, in the oceans. As marine life forms rose from the profound depths, they encountered light. Many responded to this new selection pressure by evolving light detecting sensors. It is theoretically likely that many did not.
In the late 1920s and early 1930s, some silent movie actors made the transition to the “talkies”, and other great silent era stars had unpleasant voices and disappeared.
So, too, some super-deep sea creatures either had the genetic set up to evolve or did not, and the latter vanished from pre-history, or fought their way back down to the deeper submarine ecosystems from where they arose. Good luck to them. As I say, many probably didn’t make it.
It’s speculative—but fanciful—to think about the evolution of terrestrial eyes. As in marine life, the eyes were used to hunt, avoid being hunted and select mates. Colors were certainly invented by sea creatures in truly wondrous arrays within a range of qualities of visible light that we do not see on land. Such dispersal and diffusion! The outlandish luminosity of coral life has to be seen to be believed.
Stuck in a hotel room recently, I couldn’t avoid the weird looking HD television. On it was a great cable show by the Discovery Channel called “planet earth”. I recommend it. It’s as close as I’ve seen to a faithful representation of aquatic color, but still not the same.
It mystifies me that a similar floral and foliar color based documentary hasn’t been done. Must be all the swimming around that gets the “eyeballs”, as TV industry people describe their ratings. The swimming sea creatures are so sexy, so beautifully poetic. Maybe if insects danced more often, they could catch the attention of nature documentary makers. The cameramen should use more slow motion and stop-gap action. Or perhaps the reason is that people dislike bugs. Personally, I love them.
Continuing the blog’s meditation theme, I was looked at by my eye doctor, so to speak. He described the “cup” at the back of my right eye as being more like a “collar” that “holds” strands or “branches” that radiate forward toward the lens—a bit like actual branches of a plant toward the sky—and then pass electrochemical signals (or whatever) through the “collar” back into the brain. These, his very words, are the same that arborists use. I was half-expecting him to say “dovetailing” at some point.
Which is “light” in the eye and tree metaphor? Which end the “roots”? I leave that to the poets. However, my doctor’s descriptions were remarkably like those of a tree, though, of course, on its side. Especially the “collar” part, which is exactly what a trunk is—an extended sort of tubular collar. Thus, our eyeballs are like horizontal trees.
Many fish have vertical eyes, such as the bottom fish like skates and so forth. And they definitely look like leaf debris down there on the murky ocean floor, as they gaze skyward.
Speaking of murkiness, I wish to add another thought. I speculate that one of the contributors to our ultra-sophisticated eyes—and those of our distant ancestors—was the desire for shade. The very early prehistoric sun must have been horrible, merciless—a bit like the entire world was Death Valley—a horrible place! The ability to spot a patch of shade made the difference between life and death.
Finally, a friend reminded me recently that Sir James George Frazer’s The Golden Bough, about which so many of us aging baby boomers talked endlessly (at least the goriest parts) in college dormitories, was concerned mainly with plants and trees. I had forgotten all that. It is, he said, the point of the title. Another new bit of botanical insight.
I had never looked at it that way.