Rainforests are hugely complex webs of life.
They are richer in biodiversity than any other places on Earth. Although rainforests cover less than 2 percent of the Earth's surface, they are home to more than half of all its living things. Some experts theorize that up to 90 percent of all species inhabit rainforests. Ancestors of human beings first evolved in rainforests. Our closest genetic relatives, chimpanzees and gorillas, live there still.