Data from: What drives diversification? Range expansion tops climate, life history, habitat, and size in lizards and snakes

Aim: A major challenge in ecology and evolutionary biology is to explain
the dramatic differences in species richness among clades. Much variation
in richness is explained by differences in diversification rates among
clades, and variation in diversification rates is often linked to various
traits. But what types of traits are most important for explaining
diversification? Here, we compared the impacts of different types of
traits on diversification rates among lizard and snake families, and
tested predictions about the relative importance of ecology vs.
morphology, static vs. dynamic traits, and alpha vs. beta niche traits.
Location: Global. Time period: Recent to ~200 million years ago. Major
taxa studied: Squamata. Methods: We compared the relative impacts of
traits related to biogeography (range size, range expansion), climate,
life history (viviparity), microhabitat, and morphology (body-size) on
diversification rates among all 72 family-level clades of squamates. We
compiled data on traits, and tested for relationships between traits and
diversification rates using phylogenetic multiple regression models.
Results: The best-fitting model explained ~60% of the variation in
diversification rates across squamate families. This model included only
microhabitat (proportion of arboreal species) and a novel, dynamic,
ecological/biogeographic beta-niche trait (rate of range expansion), which
explained most variance. Other variables had more variable or
non-significant contributions, including rates of climatic-niche change.
Rates of range expansion were related to species richness, larger body
size, and faster rates of climatic-niche change. Main conclusions:
Overall, we provide possibly the most comprehensive comparison of the
types of traits that can drive diversification. We also help explain
diversity patterns in one of the largest vertebrate clades. We show that
the rate of range expansion is the most important variable for explaining
diversification rates and richness patterns in squamates. We also identify
traits that help explain variation in rates of range expansion among
clades.