the stanley miller apparatus demonstrated that organic molecules could assemble spontaneously in an environment lacking free oxygen and containing water, methane, and ammonia in the presence of an abundant energy source, such as an electric discharge. the research was considered supportive of the organic soup hypothesis, which states that the primitive atmosphere provided inorganic precursors from which organic molecules could have been synthesized in the presence of an energy source. based on subsequent research, the primordial atmosphere was determined to contain less methane and more carbon dioxide. the new data about the composition of the early atmosphere had which of the following effects on origin-of-life hypotheses?