Re: Why do we have colour vision

  Color vision actually makes it easier to identify elements in our 
surroundings that would have helped our ancestors survive. For 
example, if you look at an orange tree in black and white versus color 
you will notice that it is much easier to spot the oranges with color 
vision. It is not far-fetched at all to suggest that our ancestors who 
were tree-dwellers and ate fruit, would find it advantageous to have 
color vision. Thus having color vision would provide a survival 
advantage and be selected for. 
  Let me just make a second point which is that we do not have color 
vision to be able to see fruits better. It is important to understand that 
there is no purpose in evolution. We developed color vision because it 
improved the survival of our species. The point is subtle, but I think 
important. If you are interested look up the meaning of teleological 
arguments. 
cheers,
gabriel vargas md/phd