Modelling the life-environment interface in ancient shelf seas

The co-evolution of life and environment is a dynamic system of feedbacks. Much of the evolution of life took place in localized shelf sea environments where evolving biota and redox conditions created feedbacks which are hypothesized to have increased the ecospace for life to radiate - and sometimes perhaps brought about its own demise. Models can suggest hypotheses to test ecosystem dynamics and the effects of changes to life or the environment on the other. A particular modelling challenge is to connect these localized environments to global Earth system dynamics over long timescales. A hierarchy of models is needed to separate spatial and temporal scales and allow for the construction of models specific enough to be supported by limited geological data. We introduce a 1D column model of an ocean shelf sea in the PALEO framework to represent the ecological dynamics of important early life forms such as plankton, sponges and early burrowers and their effects on redox conditions, sediment burial and diagenesis. This model demonstrates that ecological dynamics and nutrient cycling can be modelled at the finest scales, while remaining computationally viable over geological timescales. Ongoing work integrating this model with data from critical time intervals in the Ediacaran and Cambrian can provide specific hypotheses for the local behavior of the life-environment interface and can be connected to broader models for global investigations.