  The search for biosignatures necessitates developing our understanding of
life under different conditions. If life can influence the climate evolution of
its planet then understanding the behaviour of life-climate feedbacks under
extreme conditions is key to determine the 'edges' of the habitable zone.
Additionally understanding the behaviour of a temperature limited biosphere
will help towards formulating biosignature predictions for alien life living
under conditions very different to those on Earth. Towards this aim, we extend
the 'ExoGaia Model' - an abstract model of microbial life living on a highly
simplified 0-dimensional planet. Via their metabolisms, microbes influence the
atmospheric composition and therefore the temperature of the planet and
emergent feedback loops allow microbes to regulate their climate and maintain
long term habitability. Here, we adapt the ExoGaia model to include temperature
adaptation of the microbes by allowing different species to have different
temperature 'preferences'. We find that rather than adapting towards the
planet's abiotic conditions the biosphere tends to more strongly influence the
climate of its planet, suggesting that the surface temperature of an inhabited
planet might be significantly different from that predicted using abiotic
models. We find that the success rate for microbial establishment on planets is
improved when adaptation is allowed. However, planetary abiotic context is
important for determining whether overall survival prospects for life will be
improved or degraded. These results indicate the necessity to develop an
understanding of life living under different limiting regimes to form
predictions for the boundaries of the habitable zone.
