Crossing extreme habitat boundaries: Jack-of-all-trades facilitates invasion but is eroded by adaptation to a master-of-one

The invasion of new environments can be a key instigator of adaptive diversification, but the likelihood of such invasions succeeding can depend on the attributes of would-be invaders. Chief among these seems to be a generalist or ‘jack-off-all-trades’ phenotype.
Yet, despite the obvious link between habitat transitions and adaptation, we know surprisingly little about how phenotypes that might initially allow taxa to transition between habitats subsequently evolve or influence post-invasion differentiation.
We tested how a generalist phenotype of a broad diet and behavioral plasticity in marine blenny fishes has facilitated the repeated invasion of extreme environments—particularly land—and how the conditions post-invasion have impacted that generalist phenotype and associated trophic morphology.
Our data show that a wide diet and plasticity in being able to shift between environments freely has been instrumental in the progressive invasion of land by amphibious blennies. Once establi..., ,