  This paper explores coevolution and governance of common goods using models
of coevolving biospheres, in which adapting populations must collectively
regulate their planet's climate or face extinction. The results support the
Gaia hypothesis against challenges based on the tragedy of the commons: model
creatures are often able to work together to maintain the common good (a
suitable climate) without being undermined by "free riders." A long-term
dynamics appears in which communities that cannot sustain Gaian cooperation
give way to communities that can. This result provides an argument why a Gaia
scenario should generally be observed, rather than a tragedy of the commons
scenario. Second, a close look at how communities fail reveals failures that do
not fit the tragedy of the commons framework and are better described in terms
of conflict between differently positioned parties, with power over different
aspects of the system. In the context of Norgaard's work, all these
observations can be read as narratives of coevolution relevant to social
communities as well as ecological ones, contrasting with pessimistic scenarios
about common governance and supporting respect for traditional arrangements and
restraint in intervention.
