The replicating molecules of life (DNA and RNA) are composed of different nucleobase molecules linked together by phosphates and five-carbon sugars. Without the nucleobase molecules the replicating molecules of life are not possible, and without the replicating molecules life is impossible.
For a naturalistic explanation for the origin of life to become a possibility some nonbiological source for the nucleobases must be found. For several decades scientists have scoured both the Earth and the universe in an attempt to find such a natural source of nucleobases. While conditions on Earth are provably impossible for the natural formation of nucleobases, more favorable chemical conditions are found in dense interstellar molecular clouds.
Claims for the detection of the simplest of the nucleobases, namely pyrimidines, in dense interstellar molecular clouds (the richest astrophysical sources of complex carbonaceous molecules), however, have proven false. Likewise, the detection of a nucleobase molecule in the mass spectra of Halley’s comet by the Soviet Vega-1 flyby mission is only tentative. In both cases, if nucleobase molecules are present, they must be at extremely low abundance levels.
Meanwhile, a team of American and British chemists recently performed a set of calculations to investigate the possibility of nucleobase molecular formation under the conditions present in dense interstellar molecular clouds. While the team did find some possible chemical pathways for a low rate of formation of nucleobases, they noted that those same pathways appear to cause a comparable rate of dissociation for the molecules. In other words, it appears that the rate of construction for such molecules is not significantly greater than the rate of destruction. Thus, their calculations confirm why astronomers have yet to positively detect nucleobases in outer space.
Such confirmation provides yet more evidence against a naturalistic explanation for the origin of life. With no natural chemical pathway for making adequate and stable-enough amounts of nucleobases, a supernatural explanation for life’s origin must be considered.