What did the Miller-Urey experiment demonstrate?

The Miller-Urey experiment is a landmark study that simulated early Earth conditions to explore the origin of organic compounds essential for life. By combining methane, ammonia, hydrogen, and water vapor, the researchers created a reducing atmosphere that mimicked the planet's primitive environment. They then subjected this mixture to electrical sparks to simulate lightning.

As a result of this experimentation, a variety of organic molecules were synthesized, including amino acids, which are the building blocks of proteins. This demonstrated that under specific abiotic conditions—without any biological activity—organic molecules can spontaneously form. This was significant because it provided evidence that the fundamental components of life could arise naturally on the early Earth, thus supporting theories about the abiogenesis of life.

The other answers reference concepts that are either unrelated or too specific to the experiment's findings, which focused primarily on the formation of organic molecules rather than processes like photosynthesis, DNA replication, or cellular respiration.