No one knows exactly when or how life began, and the final, most important events leading to the origin of life are perhaps the least understood chapters of the story. Microbes were the first inhabitants of Earth.
Microbes decompose the waste products of other living things, creating nutrients.
They are also used to make beer, bread, and yogurt. Some say life on Earth may have begun when microbes migrated here from outer space . Others say life sprang up out of a primordial soup of terrestrial chemicals. Early Earth was dominated by volcanoes, a gray, lifeless ocean and a turbulent atmosphere. Vigorous chemical activity occurred in heavy clouds, which were fed by volcanoes and penetrated both by lightning discharges and solar radiation.