Chemical evolution refers to the process by which simple chemical compounds in the early Earth transformed into more complex molecules, eventually leading to the formation of life. This process is thought to have occurred in various environments, such as deep-sea hydrothermal vents or shallow pools, where energy sources like sunlight or lightning could drive chemical reactions. During chemical evolution, essential building blocks of life, such as amino acids and nucleotides, formed from simpler substances. These compounds eventually combined to create larger macromolecules, like proteins and nucleic acids, which are crucial for the development of living organisms.