Data from: Land colonisation by fish is associated with predictable changes in life history

The colonisation of new environments is a central evolutionary process,
yet why species make such transitions often remains unknown because of the
difficulty in empirically investigating potential mechanisms. The most
likely explanation for transitions to new environments is that doing so
conveys survival benefits, either in the form of an ecological release or
new ecological opportunity. Life history theory makes explicit predictions
about how traits linked to survival and reproduction should change with
shifts in age-specific mortality. We used these predictions to examine
whether a current colonisation of land by fishes might convey survival
benefits. We found that blenny species with more terrestrial lifestyles
exhibited faster reproductive development and slower growth rates than
species with more marine lifestyles; a life history trade off that is
consistent with the hypothesis that mortality has become reduced in
younger life stages on land. A plausible explanation for such a shift is
that an ecological release or opportunity on land has conveyed survival
benefits relative to the ancestral marine environment. More generally, our
study illustrates how life history theory can be leveraged in novel ways
to formulate testable predictions on why organisms might make transitions
into novel environments.