The Eyes Have It: Another Case of Evolution Falsification
A comparison of cephalopod eyes with mammal eyes
does not demonstrate Darwinian evolution
by J. Y. Jones M.D.
Way back in college, I was once a disciple of a very strict master, that being the concept of Darwinian evolution. In the course of my eye education, I studied not only the visual and brain anatomy of human beings, but numerous other concepts such as the chemical basis for vision, the course of photoreceptor impulses for processing in the brain, and the mystery of visual consciousness. This was after a college degree in chemistry, completing a Doctor of Medicine degree, and then a full residency in ophthalmology.
In 1973, my residency program sent me for a whole summer of basic science as regards ophthalmology. Not too deep into that intensive study, I gradually became aghast at the course my life was taking, that of being a practicing Darwinist, even though I had seldom considered all the implications. However, the sense of amazement I had while studying the perfect anatomy of the human eye, and how it interacted with incident light: its various light-sensitive opsins and vitamin A aldehydes formed when light excited them to produce a visual impulse from the photoreceptors of the retina all the way to consciousness. The instantaneous regeneration of these same pigments was surreal, and my thought processes led me, even in my spiritual blindness, to seek a stronger, higher source for all that complexity, instead of my faith in undirected blind chance.
Evolving toward Intelligent Design
Over the years, my observations and studies have led me to leave evolution behind and promote intelligent design, focusing on the God of the Bible as the best explanation for the universe itself—and more particularly, the living forms that share this planet with us. I have observed falsification of the whole concept of evolution in a thousand different ways. Yet amazingly, the Darwin party is so strong in academia, science, and government that it hangs on, calling every discovery that essentially negates all the party stands for “exciting new information” or stating “this discovery significantly advances our understanding of (fill in the blank),” or the like.
These days this sounds more and more like whistling in the dark, as this evil system could well be on the brink of obliteration. This faking or ignoring the implications of the latest unwelcome results (such as images from the Webb Space Telescope) is the only conclusion an orthodox Darwinist can take, apart from leaving Darwinism behind like I did, when the evidence against their “faith” becomes sufficiently strong. I still marvel that highly intelligent people can cling to a hope that yields no possibility of anything of lasting value, but from personal experience I can appreciate their dilemma. It matters not to me, but who wants to be black-balled?
Case in Point: The Octopus Eye
The 23 Oct 2023 issue of Current Biology has a whole series of articles comparing the vertebrate eye to the cephalopod eye. (I know the human eye best, of course.). Cephalopods include mainly the various species of octopuses, cuttlefish, and squids. Their commonly oversized eyes superficially resemble vertebrate eyes, but these articles reveal yet another problem for evolution.
Cephalopod eyes and vertebrate eyes are infinitely apart when it comes to structure and how they deal with light, so they had to develop independently with no evolutionary connections possible along the way, except for the elusive “universal common ancestor.” Cephalopods do have very large but unusual brains, especially for mollusks, and a major portion of the brain, somewhat like our own, is involved with vision. These interesting animals also have enough intelligence that they are capable of learning quickly in experimental situations. This also demonstrates that they show a remarkable degree of memory.
The appearance of paired cephalopod eyes in a live specimen is extremely similar to vertebrate eyes, obviously arranged to look like a camera, with a clear cornea behind which there is fluid plus a functional iris. A closer look reveals that a lens is also present to focus the image. Still, from the lens onward to the brain and that organ’s contribution to vision, there is little similarity in design to vertebrate eyes.
The Cephalopod Brain
Most cephalopods are equipped with large, donut-shaped brains that are as different from vertebrate brains as their tentacles are different from arms and legs. The eyes are always paired, though they function—as do the eyes of many birds—as individual visual tools, each one sharing its visual information separately with the brain. The exception is that some cuttlefish use stereoscopic vision to capture prey, a function that requires total coordination between the two eyes.
This almost universal arrangement of two eyes in both related and unrelated species is strong evidence of a common designer, since undirected evolution operates, by definition, by pure accident. There should be numerous animals that have evolved something other than a two-eye arrangement. While some shellfish have a row of light-sensitive “eyes” around the outside of the shell, true eyes, even the complex eyes of arthropods, are paired practically without exception.
When we address the embryological differences between the eyes of cephalopods and vertebrates, the findings are striking. Basically, most of these differences can be traced to how the two kinds of eyes form in the developing embryo. All three kinds of stem cells are present in both vertebrates and cephalopods. In each case mainly neural and surface ectoderm are involved, along with certain important structures from mesoderm. No endoderm is involved to any significant extent in the vertebrate eye, but it plays a role in cephalopod eye development. However, the movement of cells to form the eye (the eye cup, specifically) is quite different.
In vertebrates, the embryonic neural tube folds inward from the neural crest, and in the process it reverses the orientation of the neural photoreceptor precursors. In cephalopods, the surface epithelium invaginates, leaving the less differentiated photoreceptor precursors to maintain their original orientation. Thus, in vertebrates the photoreceptors are upside down, or inside out, so that the sensory elements that were on the original outside are deepest in the retina, facing away from incoming light. Afterward, further development of axons, ganglion cells, and retinal nerve fibers occurs, with growth toward the original outside, which has become the inner aspect of the retina.
From an Eye Doctor’s View
It would seem disadvantageous to have to see through these layers, plus the retinal blood vessels, but numerous studies have shown that it’s the best and most efficient form of vision. To see the retinal vasculature in your own eye, use a penlight and a darkened room, place the penlight gently against the upper outer (and closed) eyelid, move the light a bit briskly back and forth, and you’ll see your branching retinal vascular tree in all its glory, reliably converging on your optic nerve. This you cannot see without looking at someone else’s directly with an ophthalmoscope, or using this technique, so it is no barrier to perfectly clear vision.
Now back to the opposite setup found in cephalopods, where the invagination is of the primitive skin (surface ectoderm), and not neural ectoderm. This epithelium maintains the same orientation as before it folded, and while differentiating into photoreceptors it sends its axons directly out the back of the eye, where the nearby developing brain accepts them for bringing vision to the animal.
Cephalopod Eye Uniqueness
There are many other differences that make impossible any evolutionary contributions from the vertebrates to eye development in cephalopods, even though most structures look similar. These include the fact that cephalopods include no synapse of the photoreceptors before they enter the brain, whereas there are two synapses between the vertebrate retina and the occipital lobes. Several parts are made of completely different elements, such as the photoreceptor pigments, which are from different chemical families altogether. The lens is formed differently, and the proteins used to provide near-perfect clarity to incoming light are not at all related chemically.
Cephalopods apparently do not see color well, if at all, but unlike vertebrates (including most fish), they see polarized light very well. The structure of the photoreceptors in each group is radically different, but in both cases they nevertheless work very well. Many nocturnal vertebrates have a highly reflective membrane (known as a tapetum) posterior to the retina, but none have been discovered in cephalopods. Most people have seen this “cat’s eye” reflex in various animals, but it is absent in humans.
Despite the obvious differences, both vertebrates and cephalopods function very well in their respective environments. An evolutionist would say they “chose” a different pathway to reach the same goal—clear vision—as if evolution is the real god. But how likely is it that this would occur? Running the numbers shows clearly that formation of any complex structure like the eye by blind chance mutations is vanishingly small. For it to happen twice and produce a morphologically similar and functional result stretches the imagination beyond one chance in the number of molecules in the universe. And that’s just for an eye!
Rude Bluffing and Repetition
I read numerous articles from Current Biology (Vol 33, Issue 20) and several other sources in order to compile this summary. The science was sound, but the ubiquitous references to evolution were the only fly in the proverbial ointment. These were unnecessary, rude to evolution skeptics, and patently untrue. Such unnecessary references to a disproven theory add nothing to the knowledge of cephalopods or anything else.
There is only one satisfactory resolution to this enigma. That would of course be an all-wise Creator, who fashions all things after the counsel of his own omniscient will, and calls into existence that which did not exist. He has visited us in the person of His Son, Jesus Christ, and you can know him as I do. All my doubts vanished under the tutoring of His mighty hand. For more than fifty years I have led a life of joy, confidence, and satisfaction, although it has not been without some challenges and problems to which we are all subject. But I know it will be over soon, and I’ll be in the hands of my gracious Creator.
Blaise Pascal lived from 1623 to 1662, and died at age 39. He is one of the truly great scientists of all time, writing a treatise on sound at age 11 and another on the mathematics of conic sections at age 16. He is best known for formulating Pascal’s Law which pertains to fluid pressure. He was known first and foremost as a believer in Jesus Christ (as were most scientists before Darwin), and was assembling his deepest thoughts into a book when he died. Nobody was able to put together his many notes, so they were published as “Pensees,” which means “Thoughts.” A remarkable and timeless one of them is this:
There once was in man a true happiness of which now remain to him only the mark and empty trace, which he in vain tries to fill from all his surroundings, seeking from things absent the help he does not obtain in things present. But these are all inadequate, because the infinite abyss can only be filled by an infinite and immutable object, that is to say, by God Himself.
Why won’t things, the study of them, publication of facts about them, ever truly satisfy? Because God won’t let them satisfy. He knows the only thing that will truly satisfy is to know Him personally and well. And such satisfaction is only that found in the Person and work of Jesus Christ. Find Him and find true joy!
J.Y. Jones MD has been an eye physician and surgeon for five decades. He is a decorated Vietnam veteran, speaks Spanish, and has volunteered in 28 overseas eye-surgery mission trips. He has received numerous awards for writing and photography, and is a frequent speaker at sportsmen’s events, where he particularly enjoys sharing his Christian testimony. J. Y. and his wife Linda have been married since 1964.
Dr. Jones is an avid hunter who has taken all North American big game species using the same Remington .30-06 rifle, resulting in the book One Man, One Rifle, One Land (Safari Press, 2001); Dr. Jones helped Safari Press produce the Ask the Guides series, their most successful North American hunting books. He has written 14 books and some 300 short articles for various periodicals. For more articles by Dr Jones, visit his Author Profile page.