a process by which living organisms are thought to develop from nonliving matter, and the basis of a theory on the origin of life on Earth. According to this theory, conditions were such that, at one time in Earth's history, life was created from nonliving material, probably in the sea, which contained the necessary chemicals. During this process, molecules slowly grouped, then regrouped, forming ever more efficient means for energy transformation and becoming capable of reproduction.

Some scientists think that under present biospheric conditions new forms of life are not likely to be created from nonliving matter. Others feel that life is continuously being created but that the new forms are not so well adapted to the environment as existing ones and are thus unable to compete successfully.