In this experiment, a plant that is lower on the evolutionary scale, a douglas fir pine tree, was compared, physiologically, to a more advanced plant, the spinach plant. The workings of the plants’ photosynthesis was examine by comparing the productivity of the Hill Reaction. The Hill Reaction is the splitting of water molecules during photosynthesis. This process was observed by using the electron-accepting chemical, 2, 6 Dichloroindophenol. This chemical changes from an indigo color to clear when in the presence of free electrons. It was my hypothesis that the two plants would have a similar or identical productivity and output. This productivity and output was measured using a spectrophotometer to measure the aborbance, the less that was reduced, meaning that the productivity and output were lowered. Further experiments will examine species that are even lower on the evolutionary scale to advanced plants. These future experiments will determine just when the Hill Reaction came into existence.