Data from: Fisher's geometric model with a moving optimum

Fisher's geometric model has been widely used to study the effects of
pleiotropy and organismic complexity on phenotypic adaptation. Here, we
study a version of Fisher's model in which a population adapts to a
gradually moving optimum. Key parameters are the rate of environmental
change, the dimensionality of phenotype space, and the patterns of
mutational and selectional correlations. We focus on the distribution of
adaptive substitutions, that is, the multivariate distribution of the
phenotypic effects of fixed beneficial mutations. Our main results are
based on an “adaptive-walk approximation”, which is checked against
individual-based simulations. We find that (i) the distribution of
adaptive substitutions is strongly affected by the ecological dynamics and
largely depends on a single composite parameter γ, which scales the rate
of environmental change by the “adaptive potential” of the population;
(ii) the distribution of adaptive substitution reflects the shape of the
fitness landscape if the environment changes slowly, whereas it mirrors
the distribution of new mutations if the environment changes fast; (iii)
in contrast to classical models of adaptation assuming a constant optimum,
with a moving optimum, more complex organisms evolve via larger adaptive
steps.