Question

Bacteriorhodopsin has been found in aquatic organisms whose ancestors existed before the ancestors of plants evolved in the same environment. Propose a possible evolutionary history of plants that could have resulted in a predominant photosynthetic system that uses only some of the colors of the visible light spectrum.

Answer 1

In an aquatic environment a plant would have access to mostly blue an cyan colors of light at around 450-495 NM wavelength. if the plant contained many pigments that absorbed red light, that a plant could rarely gain access to, the plant would not be able to absorb enough light to undergo photosynthesis . The plant would most likely not be able to reproduce before it died, but if a plant had many photo pigments that would absorb blue light (which is plentiful in its environment) then the plant would thrive. it could pass on its genes and its offspring would have a higher fitness than plants that could only absorb red light. The remaining plants would only use the blue colors of the visible light spectrum because it wouldn't be efficient to have pigments that could absorb red light.