Question

When did life first appear on the earth?

Answer 1

First life on earth most probably appeared 3.7 bilion years ago , in the form of Coacervates. These were colloidal proteinaceous spherical entities, each sphere delimited by lipid membrane.

Explanation:

Coacervates used to accumulate material from surrounding sea water and could grow in size. This was possible due to chemical evolution of organic molecules in the primitive atmosphere. Coacervates are often called protobionts and prokaryotic cells definitely evolved from coacervates when self-replicating molecules were acquired.

Probably the replicating molecules even assisted as enzymes in the beginning, within the primitive cells and such molecules were ribonucleic acids (RNA).

First prokaryotic cellular life definitely evolved 3.5 billion years ago through a process called abiogenesis.