What are the basic viewpoints of spontaneous generation theory, life theory, cosmic life theory and chemical evolution theory?

Spontaneous theory: ancient people made the conclusion that life happened naturally according to phenomena. Representative views are "carrion begets maggots" and so on.

Life theory: when people know that maggots come from flies and Pasteur, people think that life is produced by parents and spores, that is, life cannot be produced naturally.

Cosmic life theory: people put forward that life on earth comes from other planets or "embryonic species" in the universe, which is based on the fact that all living things on earth have a unified genetic code, and rare elements are buried in the enzyme system, playing a special and important role.

Chemical evolution theory: advocates studying the origin of life from the law of material movement change. It is believed that under the condition of primitive earth, inorganic substances can be transformed into organic substances, and organic substances can develop into biomacromolecules and multi-molecular systems until the formation of primitive life.