On this planet, all life comes from the sun.
The sun shines its rays down on plants and plants photosynthesize, using the sun’s energy for the growth of plant cells.
Animals and people eat the plants, absorbing the life-giving nourishment and energy stored in the plant’s cells.
People eat the animals as well, transferring the stored sun energy into energy the human body can use for fuel, growth, and higher-level functioning.
When exposed, human skin directly metabolizes the sun’s rays to manufacture Vitamin D, a key ingredient in health, immunity, and strong bones.