The origin of life on Earth is a scientific problem which is not yet fully understood.
According to the most accepted theories, life originated from non-living matter through a process known as abiogenesis.
Abiogenesis
Abiogenesis is the process by which life arises naturally from non-living matter, such as simple organic compounds.
The Miller-Urey Experiment
The Miller-Urey experiment was a chemical experiment that simulated the conditions thought at the time to be present on the early Earth, and tested the chemical origin of life under those conditions.
RNA World Hypothesis
The RNA world hypothesis proposes that self-replicating ribonucleic acid (RNA) molecules were precursors to current life, which is based on deoxyribonucleic acid (DNA), RNA and proteins.
First Cells
The first cells were probably primitive prokaryotes similar to modern bacteria.