Expert: Walter Hintz - 3/8/2011

Question
I was looking at some info on the constituents of sunlight. Apparently, 14 percent of sunlight is in the form of ultraviolet light, 37 percent is light in the visible spectrum, and infra-red forms the remaining 49 percent of sunlight. Now, if so much more infra-red light comes to the Earth, why is it that plants did not develop a means to absorb light from the infra-red range than from the visible-light range?  Also, since black absorbs light more effectively than any other colour, why didn't plants develop mostly black-coloured leaves in order to be more efficient at absorbing light?

Thanks,
Geoff

Answer
Hi geoff
You are asking me questions that can only be answered in the realm of evolutionary biology. Plants do what they do because  of natural selection. Green plants absorb light in the visible light wave lengths because that is what works the best. We can only assume that other things have been tried and failed