[general_re]

I see. I believe I have been trying to describe the process of incremental improvements to you. Thus far, we have been concentrating on point-mutations - mutations of a single point on a gene - but that is, of course, not the only way new instructions are added to genomes.

But nevertheless, I think the problem you have now is that you've painted yourself into the corner of the fallacy of argument ad ignorantium, the argument from ignorance - because it has not been definitively proven true, it can be assumed to be false. Or, more precisely, because you can't imagine a path, there is no path. But, as I alluded to earlier, the limits of the universe are not determined by the limits of our imaginations.

What can I say? Examining the differences between eyes of various members of the animal kingdom, combined with what we know from the fossil record about when they arose on earth, can lead us to plausible pathways for the development of mammalian eyes.

So, here's one possibility, complete with real, live examples of each step. Simple photoreceptive cells, a la ticks -> eye spots consisting of multiple photoreceptive cells; e.g., flukes -> compound eyes composed of multiple photoreceptive cells differentiated into discrete units, viz arthropods -> simple pinhole eyes, with multiple photoreceptive cells differentiated into discrete units forming a retina behind a pinhole aperture; e.g., nautilus -> simple lens with variable focal length sitting in front of multiple photoreceptive cells differentiated into discrete units which form a retina, viz fishes and snakes -> fixed focal-length eyes with variable density lenses sitting in front of multiple photoreceptive cells differentiated into discrete units which form a retina, a la reptiles and birds -> further differentiation of discrete units of multiple photoreceptive cells which form a retina, such that discrete units exhibit variable responses to external stimuli in order to enhance image reception in low light and provide differential responses to varying wavelengths of light (i.e., color vision), A/K/A mammalian eyes.

;-)

[maro]

That's just fancier hand-waving. Living creatures are not cartoons--they are highly complex machines in which chemical reactions play the part of gears and levers. In each step that you describe, there are hundreds of unresolved questions. For example, what benefit is any kind of "lens" before the eye is fully functional? And where is the co-evolution of the central nervous system in all this? An eye is useless without a CNS. More than useless--wasted resources that would be selected AGAINST. You come closer to your real position when you say that just because something cannot be understood now doesn't mean it isn't true. I agree completely; but "knowledge" of that sort is not based on science, but on faith. As the New Testament says somewhere, faith is what is unseen but believed. You have your faith; the UFOlogists have theirs; the theists have theirs. Darwinism rests on a secular materialist faith. It's not science--at least not yet. I am agnostic on what future, real science may turn up. We are just beginning to understand DNA. But for now, it sure looks like a highly sophisticated software that creates our physical layers. (You telecom people will know what I mean.) The big question for biological science in the 21st century is WHERE this software comes from.