The weathering and dissolution effect of the rains described above must have led to oceans that were rich in various chemical compounds. This early environment is sometimes called the primordial soup. The first set of experiments that gave credence to abiogenic origins of life were conducted by Miller and Urey. In 1953, two biochemists named Stanley Miller and Harold Urey boiled hydrogen, methane, ammonia, and water vapor in a flask and introduced electric sparks to simulate lightning. What they found after several days was a complex mixture of organic molecules called amino acids.
Amino acids are the building blocks of all proteins, which are found in all living things.
These experiments showed that pre-cursors of living matter could form from the components of the early atmosphere. These experiments were significant because they suggested one possible means for the beginning of life on Earth. These experiments demonstrated that compartmentalization, thought to be critical for the assembly of certain cellular components, was possible. Recently, as a result of studies in molecular biology, it has been suggested that nucleotides such as RNA, and not amino acids, must be the precursors to life. The key questions are whether RNA can originate from some precursors present in the early Earth environment, whether this primitive RNA can self-replicate, and whether it can be present in sufficient quantities to undergo evolution into higher, more complicated structures.