Data from: Contemporary evolution during invasion: evidence for differentiation, natural selection, and local adaptation

Biological invasions are ‘natural’ experiments that can improve our
understanding of contemporary evolution. We evaluate evidence for
population differentiation, natural selection and adaptive evolution of
invading plants and animals at two nested spatial scales: (i) among
introduced populations (ii) between native and introduced genotypes.
Evolution during invasion is frequently inferred, but rarely confirmed as
adaptive. In common garden studies, quantitative trait differentiation is
only marginally lower (~3.5%) among introduced relative to native
populations, despite genetic bottlenecks and shorter timescales (i.e.
millennia vs. decades). However, differentiation between genotypes from
the native vs. introduced range is less clear and confounded by nonrandom
geographic sampling; simulations suggest this causes a high false-positive
discovery rate (>50%) in geographically structured populations.
Selection differentials (¦s¦) are stronger in introduced than in native
species, although selection gradients (¦β¦) are not, consistent with
introduced species experiencing weaker genetic constraints. This could
facilitate rapid adaptation, but evidence is limited. For example, rapid
phenotypic evolution often manifests as geographical clines, but
simulations demonstrate that nonadaptive trait clines can evolve
frequently during colonization (~two-thirds of simulations). Additionally,
QST-FST studies may often misrepresent the strength and form of natural
selection acting during invasion. Instead, classic approaches in
evolutionary ecology (e.g. selection analysis, reciprocal transplant,
artificial selection) are necessary to determine the frequency of adaptive
evolution during invasion and its influence on establishment, spread and
impact of invasive species. These studies are rare but crucial for
managing biological invasions in the context of global change.