Final answer:
The lower down in the food chain we eat, the greater percentage of solar energy we put to use, and the more people Earth can support.
Step-by-step explanation:
The statement "the lower down in the food chain we eat, the greater percentage of solar energy we put to use, and the more people Earth can support" can be explained in terms of trophic levels and pyramids of energy. At each trophic level, only about 10 percent of the energy is passed on to the next level, while the rest is used for metabolic processes or lost as heat. As a result, there is less energy available at higher trophic levels, which means fewer organisms can be supported. By eating lower on the food chain, we can access more of the available energy, allowing Earth to support more people.