Theodor Alpermann & Wolfgang Weigand
Chemical evolution is the process of the synthesis of biochemically important molecules starting from simple molecular building blocks, such as water (H 2 0), nitrogen (N 2 ), carbon dioxide (C0 2 ), and hydrogen sulfide (H 2 S), under plausible primordial conditions that governed the prebiotic Earth. It describes a process of increasing complexity from simple inorganic compounds toward first simple organic compounds that in turn formed biochemically important structures for a first living system. First life may have started up as a final product of chemical evolution. This event is probably the result of a multitude of processes, most of them not very likely, that led to a proper arrangement and activation of complex molecular building blocks. Chemical evolution on a timescale is preceded by the formation of elements in stars in consecutive nucleosynthetic processes and by the formation of first simple compounds in space at a later ...