%0 Journal Article
%T Life¡¯s Order, Complexity, Organization, and Its Thermodynamic¨CHolistic Imperatives
%A Richard Egel
%J Life
%D 2012
%I MDPI AG
%R 10.3390/life2040323
%X In memoriam Jeffrey S. Wicken (1942¨C2002)¡ªthe evolutionarily minded biochemist, who in the 1970/80s strived for a synthesis of biological and physical theories to fathom the tentative origins of life. Several integrative concepts are worth remembering from Wicken¡¯s legacy. (i) Connecting life¡¯s origins and complex organization to a preexisting physical world demands a thermodynamically sound transition. (ii) Energetic ¡®charging¡¯ of the prebiosphere must precede the emergence of biological organization. (iii) Environmental energy gradients are exploited progressively, approaching maximum interactive structure and minimum dissipation. (iv) Dynamic self-assembly of prebiotic organic matter is driven by hydrophobic tension between water and amphiphilic building blocks, such as aggregating peptides from non-polar amino acids and base stacking in nucleic acids. (v) The dynamics of autocatalytic self-organization are facilitated by a multiplicity of weak interactions, such as hydrogen bonding, within and between macromolecular assemblies. (vi) The coevolution of (initially uncoded) proteins and nucleic acids in energy-coupled and metabolically active so-called ¡®microspheres¡¯ is more realistic as a kinetic transition model of primal biogenesis than ¡®hypercycle replication¡¯ theories for nucleic acid replicators on their own. All these considerations blend well with the current understanding that sunlight UV-induced photo-electronic excitation of colloidal metal sulfide particles appears most suitable as a prebiotic driver of organic synthesis reactions, in tight cooperation with organic, phase-separated, catalytic ¡®microspheres¡¯. On the ¡®continuist vs. miraculist¡¯ schism described by Iris Fry for origins-of-life considerations (Table 1), Wicken was a fervent early protagonist of holistic ¡®continuist¡¯ views and agenda.
%K origin of life
%K far-from-equilibrium thermodynamics
%K agglutinative hydrophobic interactions
%K phase-separated catalytic microspheres
%K metabolic-replicative hypercycles
%K hyper-coupling between separate sequence spaces
%U http://www.mdpi.com/2075-1729/2/4/323