Theory of chemical evolution of molecule compositions in the universe,
  in the Miller-Urey experiment and the mass distribution of interstellar and
  intergalactic molecules
  Chemical evolution is essential in understanding the origins of life. We
present a theory for the evolution of molecule masses and show that small
molecules grow by random diffusion and large molecules by a preferential
attachment process leading eventually to life's molecules. It reproduces
correctly the distribution of molecules found via mass spectroscopy for the
Murchison meteorite and estimates the start of chemical evolution back to 12.8
billion years following the birth of stars and supernovae. From the Frontier
mass between the random and preferential attachment dynamics the birth time of
molecule families can be estimated. Amino acids emerge about 165 million years
after chemical elements emerge in stars. Using the scaling of reaction rates
with the distance of the molecules in space we recover correctly the few days
emergence time of amino acids in the Miller-Urey experiment. The distribution
of interstellar and extragalactic molecules are both consistent with the
evolutionary mass distribution, and their age is estimated to 108 and 65
million years after the start of evolution. From the model, we can determine
the number of different molecule compositions at the time of the emergence of
Earth to be 1.6 million and the number of molecule compositions in interstellar
space to a mere 719 species.
