This document summarizes several theories on the origin of biomolecules:
The Oparin-Haldane theory and Miller-Urey experiment suggested that simpler organic molecules could form from carbon dioxide and a reducing agent like hydrogen in the conditions of early Earth. These molecules could then combine to form more complex biomolecules through chemical evolution.
The theory of mica sheets proposed that the spaces between thin mica layers provided conditions for the first biomolecules to arise and evolve, similar to primitive cells. Heating and cooling could drive chemical reactions.
A Japanese study found that ocean impacts from meteorites containing carbon, iron, and nickel produced amino acids and other organic molecules, suggesting impacts could have contributed