Author(s)

C.G Chakrabarti, Koyel Ghosh

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In the present paper we have made an attempt to investigate the importance of the concepts of dynamical stability and complexity along with their interelationship in an evolving biological systems described by a system of kinetic (both deterministic and chaotic) equations. The key to the investigation lies in the expres-sion of a time-dependent Boltzmann-like entropy function derived from the dynamical model of the system. A significant result is the determination of the expression of Boltzmann - entropy production rate of the evolving system leading to the well-known Pesin-type identity which provides an elegant and simple meas-ure of dynamical complexity in terms of positive Lyapunov exponents. The expression of dynamical com-plexity has been found to be very suitable in the study of the increase of dynamical complexity with the suc-cessive instabilities resulting from the appearance of new polymer species (or ecological species) into the original system. The increase of the dynamical complexity with the evolutionary process has been explained with a simple competitive model system leading to the “principle of natural selection”.

Boltzmann-Entropy, Dynamical Stability, Pesin-type Identity and Dynamical Complexity, Lyapunov Exponents, Structural Instabilities, Biological Evolution

C. Chakrabarti and K. Ghosh, "Biological Evolution: Entropy, Complexity and Stability," Journal of Modern Physics, Vol. 2 No. 6A, 2011, pp. 621-626. doi: 10.4236/jmp.2011.226072.