Can sense organs like the eye really evolve?

Surely this depends on how you define "brain": scallops have a central nervous system, which includes ganglia for the processing of visual information and centralized coordination of reaction to visual stimuli.

Disclaimer: this post is off-topic, but I don't really want to start a new topic for it.Hi, Wollysaurus. I saw Jerry Coyne give a talk in promotion of that book (Why Evolution is True), and I was unhappy with it. His evidence for evolution was great, but his explanation of the scientific method made me sick, and he quickly turned his evolutionary talk into an argument that religion was the root of all societal problems today. All in all, it wasn't a very productive way of promoting evolution. I did not read the book, however.Dawkins is speaking tonight to promote his newest book, and I just might go see him. If I go, I'll let you know what my thoughts are.

Hi, Robert. This seems indicative of a total misconception about what evolution is.According to the Theory of Evolution, animals whose characteristics are not suitable for use in their environment will not be successful. By 'successful,' we mean "survive and reproduce."So, according to the Theory of Evolution, all the 'intermediate' eyes would have to be suitable, otherwise the organism's success is not facilitated by them.What that means is that, not only do populations of organisms evolve gradually, in an irregular series of steps, as it were; but, every 'intermediate' step in the series also has to be viable, functional and, yes, even successful.----- I highlighted the operative phrase for you. I don't personally know of any fossils of vertebrates in which the eyes are preserved. Maybe some of the other users here know of some.Molluscs don't actually fossilize much at all (except for their shells), and arthropods seem to have evolved the basic layout of their eyes almost half a billion years ago, at a time when the fossil record is, in general, very poor.So, from what I can gather, I don't see how we could realistically expect anything from the fossil record in regards to the evolution of eyes.

Hi, Coragyps. Of course. Arthropod eyes are made of the same stuff as the rest of the exoskeleton, so they tend to fossilize just as well as any other part of the bug does. There are fossils of dragonfly eyes, mantis eyes, spider eyes, etc.But, the available fossil record doesn't really show the origin of the compound eye structure, or, to my knowledge, any predecessors or intermediate forms*. This is probably because the structure evolved through the various intermediate phases in soft-bodied ancestors that did not fossilize well.*The compound eye is, however, thought to be derived from a proliferation of the ocelli, or simple eyes, which are present in both modern arthropods and their closest relatives, the onychophorans. Still, the ocellus first appears in the fossil record as a complete unit, and there are still no really good theories on how these evolved from pigment patches or eyespots, etc.