Data from: As old as the mountains: the radiations of the Ericaceae

Mountains are often more species-rich than lowlands. This could be the
result of migration from lowlands to mountains, of a greater survival rate
in mountains, or of a higher diversification rate in mountains. We
investigated this question in the globally distributed family Ericaceae,
which includes c. 4426 species ranging from sea level to > 5000 m.
We predict that the interaction of low specific leaf area (SLA) and
montane habitats is correlated with increased diversification rates. A
molecular phylogeny of Ericaceae based on rbcL and matK sequence data was
built and dated with 18 fossil calibrations and divergence time estimates.
We identified radiations using bamm and correlates of diversification rate
changes using binary-state speciation and extinction (BiSSE) and
multiple-state speciation and extinction (MuSSE) analyses. Analyses
revealed six largely montane radiations. Lineages in mountains diversified
faster than nonmountain lineages (higher speciation rate, but no
difference in extinction rate), and lineages with low SLA diversified
faster than high-SLA lineages. Further, habitat and trait had a positive
interactive effect on diversification. Our results suggest that the
species richness in mountains is the result of increased speciation rather
than reduced extinction or increased immigration. Increased speciation in
Ericaceae was facilitated by low SLA.