Can sense organs like the eye really evolve?

As Taz hinted, this is the wrong question, or at least an incomplete question. The opening post implies that scientists believe natural selection produces innovations like eyes and brains, but they actually believe it's evolution. Natural selection is just one component of evolution. The other is variation, produced through new permutations upon existing genetic material or through mutations.A better question might be, "What is the evidence that evolution can produce an eye?"The answer is that selecting the best from a number of alternatives is what evolution does. Generation after generation of selecting the best and brightest produces gradual improvements, as breeders of both plants and animals prove every year. Slow and inefficient, evolution is also immensely powerful and effective.Much faster and efficient would be a designer who with intention and purpose designed and constructed plants and animals, but we have no evidence of designers, and if the life we observe today was produced by a designer then he for some reason used a design approach that mimics evolution perfectly.A natural objection is that evolution makes tiny changes that only infrequently produce new species and that there is no evidence of it making the large scale changes necessary to evolve, for example, land animals from fish. This objection is valid if you require actual observation of such transformations, but that would also require that humans have lifespans measured in thousands of years at least. For anyone who only accept direct observation of events as evidence then there is no evidence of large scale evolution, nor for anything else that takes longer than a human lifetime.But fortunately for us, things that happen leave evidence behind, and for evolution there is copious evidence both in the ground in the form of fossils and within life itself in the form of DNA.--Percy

Hi Robert,Thank you for once again gracing us with your unsupported opinions and mental meanderings. Should there come a time when you have evidence for anything you say, that would be a good time for your next post. Until then please trust that we have a clear understanding of your unsupported beliefs and do not need constant reminding.--Percy

Eyesight is a good example of the power of natural selection. Prior to the development of vision correcting technology, those with poor eyesight were subject to selection pressures for good vision, such as are associated with hunting or detecting threats. With the invention of eyeglasses these types of selection pressures were removed, and genes for poor vision were passed on indiscriminately. As time went by the average quality of human vision has diminished. Indeed, Darwin noted on his voyage through Patagonia that the natives appeared to have significantly better visual acuity than the Europeans from the ship.Without natural selection to remove or reduce in numbers the vision challenged members of a population, visual acuity in a population should decline.Modern technology and medicine are removing many of the selection pressures that our distant ancestors were subject to. For instance, being a fast runner used to provide a survival advantage, but no more. Flat feet were a disadvantage, but no more. Sheer athleticism used to provide an advantage, but no more. Good aim with rocks or spears or bows used to provide an advantage, but no more.But new selection pressures have replaced the old. Now we need to remember where we left our eyeglasses. The dyslexia that is such a disadvantage to learning today probably had little or no impact before writing was invented.--Percy

Eating carbs causes myopia? Really?Have you considered the possibility that Barry Groves is a quack?--Percy

I just want to go on record as opposing your voluntary program of nonsense. Do you have anything to say that's relevant to the topic?--Percy

Do you have anything to say about the topic? If not, perhaps you could stop using up thread bandwidth?--Percy

Hi Robert,I think Dr Adequate asks an important question in Message 186. If you believe there isn't much diversity in eye design in nature, then please describe for us what other kinds of eyes you are thinking of that would add to the diversity.--Percy