There was an interesting article in Smithsonian Magazine about the evolution of eyes. Researchers now believe that eyes evolved "independently" fifty to sixty times. Eyes have a tremendous amount of diversity in form. The example they used was that of scallops. Their eyes are very different from ours- and not from being "simpler" but rather more complex. As they put it.
As light enters into the scallop eye, it passes through the pupil, a lens, two retinas (distal and proximal), and then reaches a mirror made of crystals of guanine at the back of the eye. The curved mirror reflects the light onto the interior surface of the retinas, where neural signals are generated and sent to a small visceral ganglion, or a cluster of nerve cells, whose main job is to control the scallop's gut and adductor muscle. The structure of a scallop's eye is similar to the optics systems found in advanced telescopes.
It is astounding that nature found a solution similar to what modern man devised for focusing light. But naturalists can always point to the dis-similarities in the array of eye morphologies as something to be expected in unguided evolution. Nature changes genetic material all the time, and on occasion these random changes will result in a combination which works better in a given environment and so forth. The similar construction to intelligently designed optics can thus be waived off. The idea is that Nature, driven by natural selection, stumbled into the same types of solutions that we humans found by design. We designed optical instruments, but nature kept randomly changing things and the selection mimicked the same results as intelligence.
Never mind that under naturalism no change can come to the genome except by chance and the environment in which natural selection is supposed to function also fluctuates by chance. Thus natural selection can only operate on what chance provides it and do so according to the bounds to which chance restricts it. Naturalists often don't like it when Theists express doubts that such structures could arise "by chance" with the claim that "natural selection is not chance". We can debate whether or not natural selection under such constraints should or should not be called "chance", but without foresight and imagination it must be strictly bound by chance in terms of both raw materials and how those materials might be shaped.
What might naturalism expect us to see genetically in a world in which the eye can appear fifty or sixty times independently? One thing would be that the independent instances would be genetically "independent" to some degree. That is, in one organism the genetic origin of the eye might be from one set of genes, but in another form it might come from another set of genes. Genes which began the random changes which over eons of time evolved an eye of very different structure. After all, with all of their morphological differences why should we expect a scallop and a fly and a human to use the same genes to build eyes that are so very different from one another in structure? Surely chance would result in one random mutation in this one, but another in that one. One should not expect these very different structures in very different animals to independently produce very different eyes from the exact same genes.
Only we do find that. And only that. Eyes vary greatly structurally and molecularly. Opsins, the chemical molecules which enable sight, are as different as the structures of eyes are. Scallops have triple the number that humans have for example. Yet the genes which direct the construction of these vast array of eyes and molecules are remarkably uniform. We noticed this before when we found out that bats and dolphins have virtually identical genomic regions used for echolocation, but at least they are both mammals and both had ears from the same genes as a starting point. Here creatures in different phyla independently developed eyes, but always from the same genes. At no point in all of those mutations and things due to chance did an eye ever arise by another path. The scientists are paid to find natural explanations for such extreme oddities, and the researchers here did their best. But one notices a vagueness in their speculations....
Although there is a diversity of eye morphologies and of photoreceptors across animals, the building blocks—the genes that control eye development—are remarkably similar. For example, Pax6 is a developmental gene that is critical for eye development in mammals, and it plays a similar role in the development of scallop eyes. In a recent study preprint, Andrew Swafford and Oakley argue that these similarities belie the fact that many types of eyes might have evolved in response to light-induced stress. Ultraviolet damage causes specific molecular changes that an organism must protect against.
“It was so surprising that time and time again, all these components that are used to build eyes, and also are used in vision, have these protective functions,” Oakley says. In the deep history of these components are genetic traits that trigger responses to light-induced stress, such as repairing damage from UV radiation or detecting the byproducts of UV damage. Once the suite of genes involved in detecting and responding to UV damaged are expressed together, then it may be just a matter of combining those parts in a new way that gives you an eye, the researchers suggest.
These are offered as "suggestions" and I am sure that those who believe in "naturalism of the gaps" will latch onto it. But even if this were the process, if evolution is so powerful then why didn't some other gene ever evolve into "UV protection" in one of the fifty-plus cases, and then sight somehow evolve out of it from those genes? If evolution is so powerful why did it even have to be from genes originally tasked with "UV protection and detection" anyway? Why wouldn't at least a few of the instances be from a gene used for something unrelated to UV protection which acquired by chance an ability to detect it anyway? That leads to the question of, if obtaining this ability is so difficult that it was never repeated in the history of eyeballs, how did it originate by chance in the first place? Do we even know that genes which produce molecules to "detect and protect from UV rays" had a single origin in living things?
Is it evolution? Sure, if change over time is evolution then that's evolution. But it is the proposition that the source of the change comes only from natural selection, unguided by nought but random changes in both genes and environment, which doesn't seem to fit what we see at the fundamental level of life. The genomes of animals seems wonderfully adaptable, but not random. The vast variation in which functions can be modified is juxtaposed against a rigid underlying design which cannot vary. Life can gets lots of solutions on sight out of these genes, but no such solutions from any others. Exactly what one would expect to find if life was designed by a Divine Intellect but the opposite of what we would expect to find if natural selection acted only on randomness guided only by randomness.
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This book is mostly not about evolution issues, it is about something much more important- how Early Genesis points to Christ. Obviously this could not be true unless He really were who scripture says that He is and that scripture is Divinely inspired. But those things are true, so it can say it. And if they are true, it would be a shame to go your whole life never knowing it.
