Data and code from: Evolutionary rescue by adaptive specialization in rapidly changing environments

Theory suggests that a population with a narrower niche can adapt more
rapidly to environmental change, all else being equal. However, a narrow
niche may be correlated with other factors that compromise evolvability,
such as a smaller population size, and it is unclear if specialist mutants
can succeed by virtue of greater evolvability when impeded by the
ecological costs of a narrower niche. Here we use simulation models to
show that specialist mutants can invade during periods of rapid
environmental change, in some cases preventing extinction. Focusing on
asexual populations, we show that successful specialist mutants typically
enjoy two types of advantages over generalists: an immediate benefit of
ignoring a habitat in which they are particularly unfit, and a longer-term
benefit of greater evolvability. By understanding the mechanisms that
yield these benefits, we are also able to show that evolutionary rescue by
specialization can be largely prevented by manipulating the schedule of
environment change. Our results demonstrate how a population may change
fundamentally under strong pressure to adapt rapidly, with implications
for both beneficial (e.g., conservation) and harmful (e.g., antibiotic
resistance) examples of evolutionary rescue.