[_uhtu]

https://en.m.wikipedia.org/wiki/Abiogenesis

"The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single event, but a process of increasing complexity involving the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. Many proposals have been made for different stages of the process."

You can always start your search on matters like this on Wikipedia.