A lens, an optic nerve, and a brain must all evolve at the same time, as well as many other necessary mechanisms. Again, insects have eyes, without having anything that resembles a central nervous system. At best, they have a decentralized nervous system.
You just can't construct a photomorph progression of believable, functional intermediates--putting together a list of eyes in ascending order of complexity does NOT prove that natural selection is what has caused the progression.
Of course it doesn't "prove" it. And it is very likely that nothing ever will. That is the difference between an inductive and a deductive argument. If you find inductive arguments to be prima facie invalid, I think that you will find that there is precious little outside the realm of pure mathematics that you can believe in. I can put together a very compelling inductive argument for the non-existence of Santa Claus, but I very much doubt that I can "prove" it, by any reasonably stringent definition of the word "prove". But something tells me you probably don't believe in Santa anyway, despite the lack of proof for his non-existence.
Nevertheless, even if it doesn't "prove" the validity of natural selection, it is evidence in its favor. It is evidence of a chronological progression of increasing functionality, specialization of traits, and diversity of taxonomy, which is what natural selection predicts should happen. It is therefore evidence supporting the validity of the theory of evolution via natural selection.
Your position is non-scientific because it is nonfalsifiable.
Of course it is. Find a fossil of a creature with complex mammalian-type eyes in some early rock layer, where the theory of evolution predicts that it should not be. Find that fossil in early Cambrian or pre-Cambrian strata, and you'll have blown a great big hole in all of evolutionary theory.
Despite its extreme implausibility (which you have essentially admitted at times on this thread--for example, that ridiculous digression into introns), you cling to it.
I wonder. One of us is blind, to be sure.
But the robots get very mad when we delicately suggest that creation is a possibility, and that the "evolution" visible in the archaeological record makes perfectly good sense, since the creator race refined their technology over time, and built on previous designs the way that all good engineers do. How could we disprove the robots, assuming there was no archaeological record of the creator race?
I like this one, although probably not for the same reasons you do. ;)
Okay, I'll bite - the short answer is, you can't disprove them, based on that particular line of argumentation. They have some evidence of their naturalistic evolution, no matter how weak we might think it is. And, by definition, we have no evidence for a creator race other than a remarkably feeble argument-by-analogy of our own. So, we can't disprove their evolution by proving the existence of a creator.
Of course, that's equally true of our evolution, as well. You cannot disprove the validity of evolution by proving the existence of a Creator, since you cannot prove the existence of a Creator. So if you want to disprove their evolution, and ours, you need to find some other way to go about it, as that's a dead end. What this is supposed to demonstrate escapes me, but there you are.
Of course, we might suppose that since they are presumably rational and logical beings, they might very well admit that their "creation" was a possibility. And so do I. Of course, they would also (being the rational and logical beings that they are) likely suggest that the probability of such a creation, especially in light of the available evidence, was vanishingly small. And so do I. ;)
Let's start with the easy stuff. This from a random website on insect anatomy: "The insect nervous system consists of a 'brain' (the result of 3 pairs 'ganglia' [a collection of neurons or nerve cells] fused together) and a pair of slender nerve cords called 'connectives' which run from it to the end of the insects abdomen, these are joined at intervals where a series of pairs of 'ganglia' (singular ='ganglion') occur the transverse fibres that connect the ganglia are called 'commissures'. There is usually one pair of ganglia per body segment, thus, as the head is made up out of 6 fused body segments it contains 6 pairs of ganglia, these are collected into 2 groups each of 3 ganglia the foremost of which is called the brain and the hindmost which is called the 'subesophageal ganglion'. The ganglia function to co-ordinate the activities of the body segment they represent, there are usually 3 thoracic ganglia and 8 abdominal ganglia but in some insects such as the Hemiptera (True Bugs) and some Diptera (True flies) the abdominal ganglia tend to fuse and have moved towards the most forward part of the abdomen." Whether centralized or decentralized, there has to be something brain-like to take in the visual info and take action based on the info. Otherwise, no use for the eye. All these components have to work together, and the more you look into it the more complicated it turns out to be. How could random mutations result in such a complicated system? What use would one or two mutations be without the whole suite of mutations necessary to make an eye work and be useful? You are indeed right, at any point in time each individual in the progression must be fully functional; but that supports my view of things. Now as to the parable of the robots. We understand machines, and microchips, at least to some extent, since we have built these things. So looking at the robots, we would suspect that they were created, since our experience with similar things indicates that the idea of machines evolving by bit flip changes is really implausible. That's what the software analogy shows; that's what the soapbox derby analogy shows. We have never built a living creature (not smart enough for that yet), so we react differently to the very same bitflip theory when applied to life on earth. But what is a living creature but a machine made of organic materials, and what is DNA but the most sophisticated software we have yet encountered? If we were to build a few living things, we would understand how ridiculous the idea is that any living creature could have evolved (in any meaningful sense) by natural selection. (Now natural selection does make sense for small changes--the kind of differences that dogs, which humans deliberately breed for various characteristics, show inter se.) As for your counter-example that purports to show how natural selection could be falsified--you are confusing yet again common descent with natural selection. If a mammal pops up in a lizard line, that may tend to disprove the common descent hypothesis, which by the way I accept. It probably wouldn't do even that, since evolutionists would more likely say that mammals must have co-evolved with lizards, and overlapped in a previously unknown way. If someone accepts common descent, then it's awfully hard to find something that would disprove the natural selection explanation for what life has a common origin--not because n.s. is right, but because the evolutionists have developed a self-reifying system that is impervious to all assaults in the way that religion is impervious to all counter-arguments. Final point: the closest thing to DNA in modern man's experience is software. Yet no one who knows anything about software could ever believe that DOS could evolve into Windows XP by bitflip mutations. Yet how is it that millions of "educated" people believe something entirely different about DNA. Answer: it's the "education," because education in practice tends to teach people how to conform to the orthodoxies of the day rather than think for themselves. P.S. whatever "induction" is, and there are smart people who believe there is no valid induction (such as David Hume, who has yet to be rebutted lo these many years), evolutionary theory is not induction. It's not serious science.