Part 6. Entropy cost of information in living neuron is estimated to be very close to the thermodynamic limit at 0.7kB per bit of information. Parallel transmission and principle of summation average with stochastic sampling is explained as the essential way of adaptation under the inevitable thermal noise. Theoretical arguments on Maxwell's demon and the negative entropy principle of information or the irreversibility of measurement are explained. Origin of life and the evolution of life are discussed from the information theoretic standpoint, in reference to the actual values of rate of information and the energy threshold of living cell.