How did life begin?

Scientists do not know the exact sequence, but the leading idea is chemical evolution: early Earth chemistry produced more complex molecules, some of which eventually became able to store information, copy themselves, or form simple compartments. NASA describes the origin-of-life problem as a central astrobiology question, not a settled one.

The main hypotheses are not mutually exclusive. Some researchers think RNA-like molecules came first because they can both store information and help reactions along. Others focus on metabolism-first ideas or on protocells, where fatty molecules formed little bubbles that gave chemistry a protected space. The reason there is still no single answer is simple: the events happened billions of years ago, left very little direct evidence, and have to be reconstructed indirectly from lab work, geology, and planetary chemistry.

So the honest answer is that life likely emerged through a long chain of prebiotic chemistry, but nobody has proven one exact route yet.