(May 13, 2012 at 3:06 pm)Annik Wrote: Here, the evolution of the eye:
The first stage is just a layer of photosensitive cells. Eventually, the layer becomes a cup, as to sense the direction of the light. Then the opening gets more narrow so that it becomes more accurate, then we get pupils, ect.
Annik, eyes have evolved more than once. Check out the calcite eyes of the trilobite which are also seen in a species of Brittlefish.