Leveraging contemporary species introductions to test phylogenetic hypotheses of trait evolution

(a) Phylogenetic studies are powerful for generating hypotheses (see Table 1) about macroevolutionary associations between phenotypic or genetic trait states (shown in blue) and potential abiotic or biotic selective environments (shown in green). Tips on the cladogram represent species. (b) Contemporary evolution in introduced and invading (I) populations can be leveraged to test these hypotheses. Introduced populations of a lineage are often replicated across multiple environments and vary in both traits and the genetic diversity available for adaptation (including through admixture among native (N) subpopulations, shown here by asterisk *).