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Old 02-27-2017, 12:04 PM
Broomstick Broomstick is offline
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Join Date: Mar 2001
Location: NW Indiana
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Originally Posted by adaher View Post
Now the eye, that brings me to another question. How DOES an eye evolve? An eye is very sophisticated, yet it has really only one purpose: to enable one to see. And until one can see, it's not doing anything to aid in survival. So how does that mutation happen? Did a fish just get born with a simple eye one day 4 billion years ago?
Although other posters have covered the uses of a proto-eye, the book In the Blink of an Eye goes into depth about the possible evolution of sight, including numerous examples from both the fossil record and modern animals. I found it an interesting read.

I'll also note that trilobites had crystalline eye lenses that, in some cases, have been preserved intact in fossils. Meaning it is possible to actually look through the actual eye lens of a creature that lived half a billion years ago, still in working order. So, not a layer of transparent cells, but a layer of deposited mineral.

Last edited by Broomstick; 02-27-2017 at 12:08 PM.