  Many mechanisms, functions and structures of life have been unraveled.
However, the fundamental driving force that propelled chemical evolution and
led to life has remained obscure. The 2nd law of thermodynamics, written as an
equation of motion, reveals that elemental abiotic matter evolves from the
equilibrium via chemical reactions that couple to external energy toward
complex biotic non-equilibrium systems. Each time a new mechanism of energy
transduction emerges, e.g., by random variation in syntheses, evolution prompts
by punctuation and settles to a stasis when the accessed free energy has been
consumed. The evolutionary course toward an increasingly larger energy
transduction system accumulates a diversity of energy transduction mechanisms,
i.e., species. The rate of entropy increase is identified as the fitness
criterion among the diverse mechanisms which places the theory of evolution by
natural selection on the fundamental thermodynamic principle with no
demarcation line between inanimate and animate.
