Fall 2010 Colloquium Abstracts - Everett Shock

November 3, 2010

Life as a Geologic Consequence

Everett Shock (Arizona State University)

Evidently, life emerged on the Earth using chemical energy to drive its metabolism. Chemical energy was available because low-temperature geochemical processes often do not reach stable thermodynamic equilibrium. This is notoriously true for oxidation-reduction reactions – the same sources of chemical energy tapped by microbial metabolism. Far-from-equilibrium states are generated during quenching and mixing processes driven by active geology. High temperature/pressure regimes often produce equilibrium states. As temperatures and pressures decrease, kinetic barriers to equilibrium induce reaction rates that rival the pace of geologic processes. In response, life intervenes as a catalyst, continuing the dissipation of energy initiated by geology. The emergence of life has much in common with the emergence of catalysis. Active research in GEOPIG combines field, analytical, experimental, and theoretical efforts to characterize the disequilibria that geology provides to life, delve into the origins of those disequilibria, and explore how biochemical processes are coupled with stalled geochemical processes in microbially dominated ecosystems found at continental hot springs, submarine hydrothermal systems, and zones of active serpentinization.