Why is nearly all the trees and bushes and grass the Color green?
Plants evolved from a common ancestral group that used the chlorophyll pigments to absorb certain portions of visible light. The pigment comes in two forms in plants: chlorophyll a and b. The two chlorophyll molecules reflect green but absorb both blue and red wavelengths that flank the ‘green gap’. Since green is reflected it is what reaches our eyes so we perceive plants as green. Chlorophyll a absorbs reasonably well in blue at a wavelength of about 450nm but absorbs most light in the red at 675-700nm. Chlorophyll b absorbs mostly in the blue end at 450 so acts to collect more of the high energy light. Plants, and other autotrophs, have the ability to fix carbon by converting the influx of solar energy into into chemical potential energy that can be consumed by animals. In this way there is a constant input of energy into the planet’s total useful quantity of energy. One possible reason for the dual peak of absorption by chlorophyll is that the first photosynthetic organism used ano
