Final answer:
The specific gases used by Miller's experiment represented the constituents of Earth's early atmosphere and demonstrated the potential for organic molecule formation under prebiotic conditions. Miller and Urey's work established a scientific basis for the abiotic synthesis of life's building blocks, such as amino acids, validating the hypothesis that primitive atmospheric gases could lead to complex organic compounds.
Step-by-step explanation:
It was significant that Stanley Miller's experiment inserted specific gases into the model because these gases represented the chemical "ingredients" that were present on early Earth. The mixture of water vapor, methane, ammonia, and hydrogen in the experiment was based on the scientific consensus at the time regarding the composition of the Earth's primitive atmosphere. These gases were important as they are thought to be the precursors to the organic molecules necessary for life.
In simulating the conditions of early Earth, Miller and Harold Urey's model supports the claim that organic precursors present could have assembled into large, complex molecules, including amino acids, by showing that an electrical discharge (simulating lightning) in this gas mixture could lead to the spontaneous formation of organic compounds. The successful synthesis of amino acids in their experiment was a groundbreaking confirmation that life's building blocks could form through natural processes in the conditions thought to be present on the prebiotic Earth.
Understanding the behavior of gases and their role in chemical reactions has been crucial in developing the foundations of modern chemistry. However, the presence of hydrogen gas in the early atmosphere, evident from the Miller-Urey experiment, poses the question of why there is so little of it now, which likely involves complex atmospheric and geological processes over billions of years.