complex system that does not decay (∆S is zero or negative), A = k3I(p)a + k4I(o)a + k5I(ef) ≥ k1I(p)u + k2I(o)u = U. Consequently, if k5I(ef) > [k1I(p)u + k2I(o)u] – [k3I(p)a + k4I(o)a], then information and order increase within the system.
Because the flux of energy across the Earth’s surface, Ef, is roughly constant, the amount of organizing information from Ef must also be constant. Hence, if this were the only factor, the biosphere would quickly come to stasis. The reason that this does not occur is because information pertaining to the ordering of the system, I(o), can be accumulated, using an appropriate information storage and retrieval system. In biology, this information storage system is nucleic acids, I(na). Therefore, in the biosphere a portion of I(ef), I(o)u, and I(o)a are retained as I(na): I(ef)na, I(o)na(u), and I(o)na(a). Hence, I(ef)na + I(o) na(a) must be > I(o)na(u) for the biosphere to continually increase in complexity.
The nucleic acid information present in the biosphere today, I(na), is the sum of the total nucleic acid information that has formed over 3.5 billion years of terrestrial biology, I(na)t, minus that portion of the total information that has been removed by natural selection or cataclysm, I(na)e. I(na) = I(na)t – I(na)e. The nucleic acid information in today’s biosphere, I(na), divided by the sum of the energy flux through the biosphere over the past 3.5 billion years, represents the average efficiency by which energy flux has been converted into conserved biological information on Earth.
This work was supported by National Institutes of Health Grants NS21328, AG24373, DK73691, AG13154, and AG16573; California Institute for Regenerative Medicine Comprehensive Grant RC1-00353-1; and a Doris Duke Clinical Interfaces Award 2005.