Codes and data from: The effect of habitat choice on evolutionary rescue in subdivided populations

Evolutionary rescue is the process by which a population, in response to
an environmental change, successfully avoids extinction through
adaptation. In spatially structured environments, dispersal can affect the
probability of rescue. Here, we model an environment consisting of patches
that degrade one after another, and we investigate the probability of
rescue by a mutant adapted to the degraded habitat. We focus on the
effects of dispersal and of immigration biases. We find that the
probability of evolutionary rescue can undergo up to three regions: (i)
starting from low dispersal rates, it increases with dispersal; (ii) at
intermediate dispersal rates, it decreases; (iii) finally, at large
dispersal rates, the probability of rescue increases again with dispersal,
except if mutants are too counter-selected in not-yet-degraded patches.
The probability of rescue is generally highest when mutant and wild-type
individuals preferentially immigrate into patches that have already
undergone environmental change. Additionally, we find that mutants that
will eventually rescue the population most likely first appear in
non-degraded patches. Overall, our results show that habitat choice, when
compared to the often studied unbiased immigration scheme, can
substantially alter the dynamics of population survival and adaptation to
new environments.