A phyloGENETIC tree is not the same thing as a taxonomic tree, which is what Cal described. rRNA and molecular studies are used in phylogenetics to determine relations between species.
1 As the light intensity increases, the rate of photosynthesis increases. 2  However, the rate will not increase beyond a certain level of light intensity. 3  At high light intensities the rate becomes constant, even with further increases in light intensity, there are no increases in the rate.
Light is an extremely important factor for the process. If there is enough water, carbon dioxide, and the temperature is right, light becomes the factor which will affect photosynthesis. Most of the time, when the intensity of light is high, you will get a a greater rate of photosynthesis.