T175 Teaching and Learning about Complex Earth Systems: Effective Strategies in Undergraduate Classrooms and Teacher Development Programs

Sunday, 5 October 2008
1:30 PM - 4:45 PM

Earth Systems Do Not Evolve to Equilibrium

Paper number: T175-4
Program: Technical Sessions
Time: 2:00 PM – 2:15 PM

Authors

Abstract

Energy dissipation normally modeled/taught as chemical/physical processes winding down to equilibrium does not lead to evolution. Non-equilibrium earth systems evolve only because tectonic/solar energy keeps them far from equilibrium where they increase in complexity, diversity, interconnectedness with time through the interplay of three distinct evolutionary mechanisms: elaborating evolution [i.e. General Evolutionary Algorithm (GEA; subsumes biological evolution)]; fractionation (e.g. atmospheric and rock evolution); self organization (increasing organization via simple rules; e.g. oscillating chemical reactions and networks). Biological evolutionary theory is widely taught (but not the GEA); fractionating evolution is taught as an equilibrium system; and self-organization is nearly invisible (although common). Earth as a system of systems is understood by exploring how the positive-negative feedbacks among the three evolutionary mechanisms result in Earth system evolutionary change; i.e., some fractionations are mediated by biological processes (and some not), but not by biological elaborating processes, although at geological time scales biological elaboration can change chemical fractionation. Each mechanism is distinct but they interlink by universal features not found in equilibrium systems, e.g. evolve to sensitive dependent critical states, leading to avalanches of changes following power law distributions with fractal organization, dynamically behaving as strange attractors often with bistable behavior.

We propose an encompassing theory of Earth systems where the theoretical underpinnings of each evolutionary mechanism is introduced first, followed by exploration of how the evolutionary systems interact to integrate the lithosphere, atmosphere, hydrosphere, biosphere into a unitary evolutionary system. We incorporate several simple conceptual or computer models within our lesson plans that illustrate the principles of self organization, e.g. Self Organized Criticality, Bak-Sneppen ecosystem, cellular automata, oscillating chemical reactions. Future work requires explicating complex systems mechanisms and their interactions, and imbedding them in introductory and upper level Earth Science classrooms to put all Earth systems on an evolutionary theoretical foundation.