This article is Part 2 of our scientific analysis of evolution (go here for Part 1 in case you missed it). Though Part 1 focused on reproduction issues, the main concept is the lack of any plausible way to incrementally change from one type to another in a Darwinian evolution fashion. The only way that Darwin could ever have one species change into another is through a slow gradual process of tiny, micro-mutations within the genes of some common ancestor. In fact, Darwin says everything must be the result of “infinitesimally small inherited modifications,” each of them being profitable to the preserved being.[i] But there are so many things that cannot be explained as a slow gradual build up from something simply, especially given that each incremental step must be advantageous to the individual in order for it to survive through natural selection.
A classic example of this is found in the human eye. The evolutionist would argue that it is easy to show how the eye evolved because 2% of the eye would be more advantageous than 0%, therefore those organisms with 2% of the eye would survive through natural selection. And those would then evolve, or rather genetically mutate, to have 4% of the eye. And those with 4% of the eye would be better adapt to survive than those with 2%, and so on. However, the flaw here is that 2% of the eye does not equate to 2% of eyesight. Yes, having 2% vision is better than 0% but a species won’t have even 0.1% vision until 100% of the eye is present. There is a difference in a partial percentage of the components of the eye itself and having some partial percentage of eyesight. Think about it. If you only had a cornea, but no pupil, or iris, or retina, or rods, or cones, or optic nerve, then you could not see at all. Nothing. 0%. So what advantage would an organism have to genetically mutate a cornea, which gives it no sight whatsoever, while it waits generations to finally genetically mutate a lens? Because, remember, each change must be from an infinitesimally small modification (one micro-mutated gene at a time). So why would natural selection preserve the genes of the organism with a cornea over an organism with no cornea if neither organism could see?
Further still, if an organism were to then completely develop an eye, yet had none of the support structures, the eye still would not be functional. Support structures would be those things that provide tears and blood to nourish and lubricate the eye; the muscles that allow the eye to move; the structures that give the eye protection from injury, like the eye lid and the epithelium of the cornea; the optic nerve to send the signals from the eye to the brain; and a brain to understand what those signals mean. If there were not a brain to interpret what the eye sees, then the eye would still be useless to the organism. Granted, some organisms are able to have eyesight without those support structures and without a brain (and we’ll talk about some of those below) – but not our eye type. For our eye type, the camera eye, something must be able to interpret what the eye sees into something meaningful especially since what our eyes “see” is upside down and double. Our brain is able to combine and convert those double upside-down images into something that makes sense. And all of that work is done by multiple parts within the brain.[ii] Otherwise, the eye would basically just be one annoyance, where dust and particles would scratch and irritate this new feature that didn’t provide any use for the organism. It would be like someone giving a farmer in the 1800s a smart phone.
Now, at this point in the line of reasoning, the evolutionist will show examples of the different types of complexity of eyes that are found in nature. They will even show how they could have progressed from one to another. Some bacteria have just a light sensitive spot with a pigment screen behind it. Next there are some multi-cellular animals that have a similar arrangement set into an optical cup to give improved direction-finding capability. The nautilus has a pinhole eye with no lens, and then the squid eye adds a lens. There is the simple eye, the compound eye, and the camera eye (human eye). So there is wide variety of eye types with various levels of complexity. But does that mean that the more complex eye evolved out of the simpler eye? It is a pertinent question especially since all of these eye types co-exist together!
We must first assess the components of these different eye types. Are the components similar across all eye types to where there could be an incremental building up of something complex? In other words, does the simplest eye have just a retina, the next complex eye adds a lens, and the next adds a cornea until you find all of the components present in the most complex eye – where each of those intermediate eyes were fully functional? Well, those evolutionary charts would have you think so, but that is not the case at all when you look at the details. Each of these different eye types uses entirely different structures. It is not a series of structures that are built upon one another over millions of generations. The compound eyes of insects are made up of hundreds of units called ommatidia that has a cluster of photoreceptor cells surrounded by support cells and pigment cells, each with its own lens. This is a much different structure than the human eye (pictured below). What would an intermediate eye between these types be? It would be something that could not see.
Human camera eye
As you read more about the different eye types even in the camera-type eye it is amazing to see the unique design for each organism’s environment. And the design to make that eye work in that environment goes way beyond just what structures are present. It has to do with the shape and location of those structures; where the eye is located on the head; what muscles are around it. And these variations occur even within the same eye type, the same phylum, and the same genus! The eyes of some fish in the deep sea show variations in the basic spherical design. For some, their field of view is restricted to the upward direction which makes the eye a tubular shape. Some have their field of vision restricted downward, with a second lens and retina attached to the main eye so they can detect bioluminescent creatures. Think about the genetic mutations necessary to develop those two vastly different eyes found in the same phylum. One of them has a second lens and retina attached to its eye. Unless you were already in the sea but stayed mainly in shallow waters, this genetic mutation gives you no advantage whatsoever.
The placing of the eyes in the head of the organism varies as well. Predators like cats and owls have forward-pointing eyes and can judge distance by binocular triangulation. The prey for those animals, like mice and rabbits, have eyes opposite each other to give near-complete coverage of their surroundings. There are even different structures between nocturnal and diurnal animals that would have the same general eye type (compare a squirrel to a raccoon). Diurnal animals have smaller, thinner lenses placed toward the front of the eye with more cones photoreceptors to detect color and fine detail. But nocturnal animals have almost spherical lenses that fill most of the eye cavity so they can capture the maximum amount of light as possible. They also have a huge amount of rods photoreceptors to detect size, shape, and brightness better, but not color. They even have a slit pupil so it can close more effectively in bright light than a round pupil. They also have a “tapetum lucidum, a reflector behind the retina designed to give receptors a second chance to catch photons that were missed on their first passage through the retina.”[iii] Even the Encyclopedia Britannica can’t shy away from the use of the word that most clearly describes this unique feature for nocturnal animals: design. And these differences would be between two organisms that have the same general eye type, the vertebrate camera eye, yet have vast differences in the type and number of photoreceptors, a slit pupil, the shape of the lens, and a reflector behind the retina. These aren’t trivial differences either. Each one of those would require its own genetic mutation. Consider which genetic mutation would have come first, and not just for the eye, but for being a nocturnal animal. What if a diurnal animal had a slit in its pupil before it “evolved” to be nocturnal? Or what if the diurnal animal genetically mutated to have the tapetum lucidum first? What advantage would that animal have? None. Yet for Darwinian evolution to work, each new variation must come from infinitesimally small inherited modifications each of them being profitable to the preserved being.
Let’s put the pencil to the paper for the two “simplest” eyes to see if they could even genetically mutate from one to the other. Here are the descriptions of these two eye types.[iv]
The evolutionary chart is going to show a light spot that just adds a pupil. But taking the steps required by Darwinian evolution, consider the genetic mutations that must occur to “evolve” from one eye type to another - genetic mutations that are not controlled by the organism itself nor by the environment it is subjected to. Nature can’t predetermine the appropriate order for each change to occur. It must all be random. This is the problem with “reverse engineering” to find Darwinian evolution progressions. The “engineering” part of that puts logic and purpose and intelligence into why each change was made to improve on a design. Engineering would say we increased the size of the heart so we must increase lung capacity to go with it. But a blind, random process can’t do that. Darwinian evolution can’t decide that one particular change would help and then make that change. It must wait on the blind luck of a genetic mutation to give it that beneficial change. And it can’t make all those changes at one time because that would be a “sudden jump” in nature. Nature doesn’t make sudden jumps, only God does. It must be the result of a slow, gradual process with infinitesimally small changes. So every change is blind to its effect, and must leave all previous and all future changes unaffected. That being said, we can’t presuppose the order of those genetic changes involved because that involves foresight and planning; and nature does not have that on its own.
Let’s think through the incremental changes between these two incredible “simple” eyes, changing from a Planaria eye to a Nautilus eye. The organism would need a genetic mutation to produce millions of photoreceptors instead of just a few. Now what would a Planaria do if it suddenly had millions of photoreceptors for its pigment cup eye, which only needs a few? Would that be an advantage for it? Then the Planaria’s genes must mutate to decrease the size of the aperture. But how would it be able to still see if the aperture size is decreased but the size of the eye is still only 0.004 inches? Meanwhile, what have all those changes done to the function of the pigment cup eye for the Planaria? Because, see (no pun intended), at this point, the Planaria’s eye is not a pinhole eye. It is a pigment cup eye with too many photoreceptors and too small of an aperture. Hopefully for the Planaria’s sake the next genetic mutation will be to increase the size of the eye 100 times from 0.004 inches to 0.4 inches, assuming this genetically mutated Planaria has survived natural selection, and assuming there are enough other Planaria in this generation that also have genetically mutated to have millions of additional photoreceptors, a smaller aperture, and larger eye size so that all of those traits are passed on. Then the Planaria needs a genetic mutation to acquire muscles in order to move this new eye. Of course that mutation may not get the size, location, and mobility exactly right. It may take multiple generations until the muscles are precisely located to work with this newly mutated eye structure. Lastly, it needs to genetically mutate a pupil, and it must be one that can vary in diameter.
Even if by some miracle (pun intended) all of those genetic mutations occurred individually and incrementally, each one somehow being beneficial to the Planaria, we still don’t have a Nautilus eye. We have a Planaria with a pinhole eye. What is a Planaria going to do with a pinhole eye? Otherwise, we have to start factoring in all of the other genetic mutations that would have to occur alongside the mutations of the eye to change all of the other systems of the body to “evolve” from a Planaria to a Nautilus. Consider the drastically different reproductive systems, digestive systems, circulatory systems, and even the environments in which they live between the Planaria and Nautilus. Not to mention, the Nautilus would have been smart to hold on to the Planaria’s ability to regenerate. But it even begs the question, why did the Nautilus eye stop there in its evolution? Shouldn’t it have continued to genetically mutate to gain a lens over its eye? Richard Dawkins admits to being baffled by the nautilus that has never evolved a lens for its eye over its hundreds of millions of years of existence. He says it is an eye that is “practically crying out for this particular simple change.”[v] Yet it has remained the same.
The eye is an amazing organ, no matter which eye type you study. There is a wide range of eye types that so specifically meet the requirements of the organisms which bear them that it truly is miraculous, or rather, statistically improbable to have occurred through nature alone. (I’ll include some more info below on other eye types if you are interested.) I heard one evolutionist say that they aren’t intimidated by the improbability of evolution because hey, someone has to win the lottery. But for even just the one organ of the eye to develop so perfectly suited for that particular organism’s needs, it would be more like the SAME person winning the lottery every week for the next 5 billion years. Eyes vary in their visual acuity, the range of wavelengths they detect, their sensitivity in low light, their ability to detect motion or to resolve objects, and whether they can discriminate colors – all depending on the need of the organism. When you consider that, it is as though no two species have the same kind of eye structure or sight mechanism.
It is so varied even within the same genus that it becomes statistically improbable that each eye genetically mutated from some common ancestor, especially when there is no evidence of eyes AT ALL in the fossil record before the Cambrian period. That means the Cambrian explosion was not just an explosion of body type, but eye type, all showing up at the same time in the fossil record. It means all those eye types existed together at the same time – just like they do now. Even though the evolutionary pictures try to show a linear progression between types, while intentionally omitting the hundreds of genetic mutations that would have to occur for that to happen, evolutionists now must also claim the evolution was not linear but parallel! But what are the statistical odds of ALL eye types developing at the same rate and time and being kept through natural selection in order to all appear in the fossil record of the Cambrian explosion at the same time – if it were done through Darwinian evolution? [That sounds to me like maybe they were all uniquely created at the same time.] The evolutionists contradict what they try to indoctrinate – that each type gradually merges into another through a serial, linear fashion of infinitesimally small genetic modifications each being beneficial to the organism. So they show a linear progression when it’s convenient and a parallel explosion when it is not. Every technical consideration of the amazing wonder of the eye smacks of divine design of a specific type perfectly suited to the organism. Meanwhile evolutionists just throw in the word “evolved” with no detailed explanation, as if that makes it so. But the detailed evidence, or lack thereof, show a different picture.
[i] Phillip E. Johnson, Darwin on Trial (Downers Grove, IL: InterVarsity Press, 1993), 33.
[iii] https://www.britannica.com/science/photoreception#ref1005219 “Diversity of Eyes”
[iv] https://www.britannica.com/science/photoreception#ref1005219 “Diversity of Eyes”
[v] Phillip E. Johnson, Darwin on Trial (Downers Grove, IL: InterVarsity Press, 1993), 35.
The Amazing Eye
Lens eyes. Lenses are composed of a refractive index material that reduce the angle over which each photoreceptor receives light. This allows the lens to form an image focused onto the retina. Each organism type varies the shape of the lens. Organisms focus by either physically moving the lens toward and away from the retina or by using eye muscles to adjust the shape of the lens. But not even in the same genus does the lens develop the same way. And this is important because evolution must come through the genetics and embryonic development. The vertebrate eye lens develops from the epidermis overlying the optic cup, which develops in the exact place to fit the optic cup perfectly. Researchers then discovered that the optic cup itself is the organizer which induces the epidermis to differentiate into this tailor-made lens. The common frog (Rana fusca) eye develops this way. So it was discovered that if this optic cup is removed in the embryo, then no eye lens develops at all. However, for the edible frog (Rana esculens), if the optic cup is removed from the embryo, the eye lens will still develop just the same. The lens develops completely differently in the embryo – even within the same genus!
Corneal Eyes. The cornea is the transparent membrane in front of the eye that separate fluids inside the eye from fluids outside the eye. It functions to increase the focusing power of the eye but the optical power is reduced when there is fluid on both sides of the membrane (it’s why we can’t see well if you go under water and open your eyes).
So animals that move from air to water and back (like seals, otters, and diving birds) have uniquely shaped corneas. Seals have a flat cornea with a spherical lens to produce images. Diving ducks use a different method. They squeeze the lens into the bony ring around the iris, forming a high curvature blip on the lens surface to shorten the focal length. A summary statement from this article about the different eyes says that “the eyes of animals are diverse in structure and use distinct optical mechanisms to achieve resolution.” What is the seal had genetically mutated a flat cornea but didn’t have a spherical lens? Or what if it genetically mutated the spherical lens but didn’t have the flat cornea? What if the diving duck hadn’t yet genetically mutated the bony ring around the iris in order to adjust the focal length? What were those organisms doing before all of those necessary changes occurred?
For organisms not under water, the lenses are flattened and weakened compared to say, a fish lens. In humans, the cornea has an ellipsoidal shape giving it only one axis of symmetry, where the best image quality occurs. Therefore along this axis is a high density of photoreceptors, known as the fovea, which results in acute vision.
Concave mirror eyes. Scallops have about 50-100 single-chambered eyes. And though those eyes have a lens, it is too weak to produce an image. So it has a mirror, made up of alternating layers of guanine and cytoplasm, in the back of the eye that reflects light to the photoreceptors. The mirror structure produces constructive interference for green light to give it a high reflectance. The Pecten actually has two retinas, one made up of a layer of microvillus receptors close to the mirror and out of focus. The other retina is made up of a layer with ciliary receptors in the place of the image. The second layer responds when the image of a dark object moves across it causing the scallop to shut its shell in self-defense.