Can sense organs like the eye really evolve?

Let's add scallops to the list. Plenty of eyes, but no brain.

It's not clear that one would call that a brain.How do you feel about sea urchins? Body of Sea Urchin Is One Big Eye :

To be precise, one more than a non-light-sensitive cell. And since a non-light sensitive cell uses lots of biochemicals, half of your post is arguably technically true.Don't you guys have to perform some sort of pennance to atone for that? I'm sure it was inadvertent, but even so you can't be too careful.

This is, of course, not true. What a splendid argument for evolution and against creationism. Thanks. I guess you'll be switching sides now?

Do you mean by that that you wish to rule out anything that looks like an intermediate form?

Descartes.

Now this is a perfect illustration of why you shouldn't read things written by liars and fools.The broadest classification might distinguish between eyespots, pit eyes, lensed eyes, multiple lensed eyes, reflector eyes, apposition compound eyes, refracting superposition eyes, reflecting superposition eyes, parabolic superposition eyes ... but those are only fairly crude classifications. When you look at the details, thee's more diversity still. For example, squid and mammals both have simple lensed eyes, but in mammals the focus is changed by changing the shape of the lens whereas in squid the same function is served by moving it backwards and forwards. Or to take another subdivision, trilobites have appositional compound eyes, but unlike everything else with appositional compound eyes their eyes had hard lenses.And then there are the complete weirdos like copepods ...Edited by Dr Adequate, : No reason given.

Is this something else you read somewhere or did you make it up all by yourself? If the zoo happens to only contain mammals, then one would indeed correctly conclude that. Otherwise, not so much. It is in fact not merely unlikely but impossible for evolution to have produced the world that you have made up in your head. But the question is whether it is responsible for phenomena in the real world, the one that actually exists.

No, I said the exact opposite. And, as I have pointed out, what you read was a lie. You think the difference between a lensed simple eye and a reflecting superpositional compound eye is "trivial"?What differences would you think were consequential? And many of the types of eye that I listed do not have lenses. Instead they have a wide variety of substitutes. Just as we would run from the fiveness of two plus two. Your belief is untrue. What an enormous surprise ... you having a belief that isn't true. I'm staggered.Darwin did not in fact adduce the fantasy world in your head as evidence for anything, because he did not live in your head.Edited by Dr Adequate, : No reason given.

What are you talking about? Specifically, they are different in having a completely different kind of eye. Hey, look, you said something true! That's exactly what I did say.

Which is why this imaginary lack of diversity doesn't exist. And this is not true. Moreover it is written in the prose style of an instruction manual for a Korean washing-machine, can't you do anything about this?---Now, here's an idea. Please suggest two possible basic designs for functional eyes which are more different from one another than the differences between the types of eyes found in nature.Edited by Dr Adequate, : No reason given.

Really? Why do humans and elephants alike "need" a blindspot while squid don't?Why do humans, apes, and Old World monkeys need one sort of three-color vision while New World monkeys need another? Are colors different in South America?

And yet you have not answered my question, which I repeat: You keep saying how similar they are, and yet you cannot imagine anything more dissimilar. And your silence on this point speaks louder than your words.

Then perhaps you could answer them instead of evading them.

Shall I take that as a "no" then?So stop pretending that they're all very similar, when you can't even imagine a greater degree of diversity than they actually exhibit.