How did life originate on Earth?

Abiogenesis — the transition from non-living chemistry to self-replicating biology — is not understood mechanistically. The 'RNA world' hypothesis is influential but incomplete; alternative scenarios include metabolism-first, lipid-world and hydrothermal vent models.

Open sub-questions include the source of chirality, the assembly of the first cell membranes, and the order in which the genetic code, translation, and metabolism arose.