Data from: Coincident transitions across elevation and origins of functional innovations drove the phenotypic and ecological diversity of lungless salamanders

Ecological opportunity (EO) is an important catalyst for evolution.
Whereas theory often centers around a lineage encountering a source of EO
in isolation, in practice, they experience numerous sources of
opportunity, either concurrently or sequentially. Such multiplicity can
obscure the macroevolutionary signature of EO. Here, we test the effects
of elevation (a proxy of the “mountain effect”) and an array of functional
innovations on the evolutionary history of plethodontid salamanders, a
diverse and charismatic radiation of lungless amphibians. Functional
innovations unlock access to novel microhabitats, ultimately enabling
sub-lineages to occupy a diverse range of ecological niches, particularly
in lowland areas where those niches are more abundant. Consistent with
expanded ecological opportunity, such transitions to lower elevation
result in rapid phenotypic evolution. At high elevation, by contrast,
rates of phenotypic evolution and phenotypic disparity decline, reflecting
a loss of phenotypically extreme ecological specialists. Transitions in
elevation and the origin of innovations appear largely coincident among
lungless salamanders, suggesting myriad sources of EO. The magnitude of
the “mountain effect” on evolutionary rates (~10-fold) is on par with or
greatly exceeds that of islands, lakes, and coral reefs on other iconic
vertebrate radiations. Therefore, we find that elevation acts as a major
ecological moderator and, in concert with functional innovations, shapes
the ecological and phenotypic diversity of lungless salamanders.