The human eye accomplishes many precise, sophisticated tasks, including adjustments for light and dark settings, focusing to close and far objects, and correction for aberration. It does not seem logical that these could have evolved slowly over time. Oddly, Darwin admitted that eyes seem difficult to explain from evolution, but obviously he believed that they did evolve and gave a supposed overall scenario. 1
Evolutionists must say that eyes evolved 40-60 times separately. This makes them say that eyes are “easy” to evolve 2 (some more than others), but this clashes with our intuition.
Evolutionist: We can imagine a slow, gradual path from no eye to the fully functioning eye: (1) Improvements to light-sensitive pigment molecules; 3 (2) Ability to detect the direction of light, perhaps by a cup-shaped light-sensitive patch; 4 (3) A pinhole eye, which is a natural extreme of a cup shape; 5 (4) A gradual “lens” by, say, a jelly-like substance; 6 etc, etc.
Response: This scenario sounds simple enough, but in reality, it isn’t. (Fairy tales sound simple enough, too, but they’re not practical.) First, even the most simple photoreceptors are extremely complex, and to migrate to a cup shape would require many new proteins, each of which are staggeringly complex. 7
Second, increasing the clarity of the image from the eye would mean absolutely nothing unless the brain was wired to receive and understand this clear image. Take out the processor on a top-of-the-line digital camera, and you will receive no image at all, even if you have the best lens and CCD sensor. For instance, in his book Climbing Mount Improbable, Dawkins says that he filled a bag with water as a “lens” and was able to make the image clearer by trial and error while “poking” the bag. 8 The problem is, the brain would have no way of knowing which image is “clearer” if it’s not set up to receive clear images. Dawkins is looking at the bag with his crystal-clear eye and brain that is wired to understand these images, but the first animals would have none of these features.
Response: Actually, Nilsson and Pelger used unrealistic assumptions in their computer program: (1) They forgot to factor in the complexity of the new proteins required as the eye developed; (2) They forgot that without a brain to understand the clearer images, the improvements of the eye would not make any difference; and (3) They oversimplified the mutation process. They thought that each animal could have, say, a 1% change in some aspect of the eye, like the lens shape, cup, etc. But the eye isn’t the same as toy Legos or Lincoln Logs—it is a highly complex machine. Changing anything is much more likely to break the machine than to improve something. Nilsson and Pelger did not take this into account.
Site Under Construction
This site is still under construction. It needs more references, citations, and debate arguments. If you would like to help, please view the community page.
Dawkins, R. (1996). Climbing Mount Improbable. New York: Norton.
- Dawkins, 1996, p. 196: “Nothing is as difficult to evolve as we humans imagine it to be. Darwin gave too much when he bent over backwards to concede the difficulty of evolving an eye. And his wife took too much when se underlined her scepticism in the margin. Darwin knew what he was doing. Creationists love the quotation that I gave at the beginning of this chapter, but they never complete it. … “ ↩
- Dawkins, 1996, p. 190: “A central message of this chapter is that eyes evolve easily and fast, at the drop of a hat.” ↩
- Dawkins, 1996, p. 142: “The first faltering steps up the slopes of Mount Improbable would have consisted in the gradual improvement of pigment molecules. There is a shallow, continuous ramp of improvement–easy to climb in small steps.” ↩
- Dawkins, 1996, p. 146: “The next step of improvement must have been the acquisition of some rudimentary sensitivity to direction of light and direction of movement of, say, a menacing shadow.” ↩
- Dawkins, 1996, p. 150: “The pinhole effect is just an extreme version of the cup effect that we have already met as an aid to telling the direction of light. It belongs only a bit farther up the same slope of Mount Improbable and there are no sharp precipices between.” ↩
- Dawkins, 1996, p. 158: “It is not difficult, then, for rudimentary lens-like objects to come into existence spontaneously. Any old lump of half-way transparent jelly need only assume a curved shape (there are all sorts of reasons why it might) and it will immediately confer at least a slight improvement over a simple cup or pinhole. Slight improvement is all that is required to inch up the lower slopes of Mount Improbable.” ↩
- http://creation.com/book-review-of-dawkins-climbing-mount-improbable ↩
- Dawkins, 1996, p. 167: “It is not at all difficult to imagine the gradual evolution of mechanisms for changing focus. When experimenting with the polythene bag filled with water, I quickly noticed that the sharpness of focus could be made better (or worse) by poking the bag with my fingers. Without being consciously aware of the shape of the bag, without even looking at the bag but concentrating on the quality of the image being projected, I simply poked and squashed the bag at random until the focus got better. Any muscle in the vicinity of a lump of vitreous mass could, as a by-product of contracting for some other purpose, incidentally improve the focus of the lens. This opens up a broad highway for gentle improvement all the way up the slope of Mount Improbable, which could culminate in either the mammal or the chameleon method of changing focus.” ↩
- Dawkins, 1996, p. 163: “Nilsson and Pelger’s purpose was not only to show that there is a smooth trajectory of improvement from a flat non-eye to a good fish eye. They were also able to use their model to estimate the time it would take to evolve an eye from nothing. The total number of steps that their model took was 1,829 if each step achieved a 1 per cent change in the magnitude of something. … They assumed that for every 101 animals possessing an improved eye who survived, 100 animals without the improvement survived. As you can see, this is a low intensity of selection as common sense might judge it–you are almost as well off without the improvement as with it. They deliberately chose a low, conservative or ‘pessimistic’ figure because they were bending over backwards to bias their estimate of rate of evolution towards being, if anything, too slow.” ↩
- Dawkins, 1996, p. 166: “A skeptic about the power of evolution, such as Emma Darwin, is naturally drawn to the view that an organ as notoriously complicated and many-parted as an eye, if it can evolve at all, will take an immense time to evolve. Nilsson and Pelger’s final estimate was actually astoundingly short. At the end of the calculation, it turned out that it would take only bout 364,000 generations to evolve a good fish eye with a lens. It would have been even shorter if they had made more optimistic (and this probably means more realistic) assumptions.” ↩