YCCSA Presentation 18/03/2021

Coloured noise and the evolution of environmental tolerance in artificial evolutionary systems

Ecological, environmental and geophysical time series consistently exhibit the characteristics of coloured noise. In this talk we argue that our models of environmental variability should also exhibit those characteristics, especially when exploring artificial evolutionary dynamics.

To illustrate and explore the effects of different noise colours, we apply a simple evolutionary model that examines the trade-off between specialism and generalism in fluctuating environments, and the effects of reproductive rates on evolved levels of environmental tolerance. The results of the model clearly demonstrate a need for greater generalism as environmental variability becomes 'whiter', while specialisation is favoured as environmental variability becomes 'redder'.

Pink noise, sitting midway between white and red noise, is shown to be the point at which the pressures for generalism and specialism balance, providing some insight into why 'pinker' noise is increasingly being seen as an appropriate model of typical environmental variability.

Ultimately, we argue that the characteristics of a model's environmental variation matter, with noise colour not only influencing evolved levels of environmental tolerance but also the interaction between reproductive rate and environmental tolerance.