Data from: Analysis and visualization of complex macroevolutionary dynamics: an example from Australian scincid lizards

The correlation between species diversification and morphological
evolution has long been of interest in evolutionary biology. We
investigated the relationship between these processes during the radiation
of 250+ scincid lizards that constitute Australia's most species-rich
clade of terrestrial vertebrates. We generated a time-calibrated
phylogenetic tree for the group that was more than 85% complete at the
species level and collected multivariate morphometric data for 183
species. We reconstructed the dynamics of species diversification and
trait evolution using a Bayesian statistical framework (BAMM) that
simultaneously accounts for variation in evolutionary rates through time
and among lineages. We extended the BAMM model to accommodate
time-dependent phenotypic evolution, and we describe several new methods
for summarizing and visualizing macroevolutionary rate heterogeneity on
phylogenetic trees. Two major clades (Lerista, Ctenotus; > 90 spp.
each) are associated with high rates of species diversification relative
to the background rate across Australian sphenomorphine skinks. The
Lerista clade is characterized by relatively high lability of body form
and has undergone repeated instances of limb reduction, but Ctenotus is
characterized by an extreme deceleration in the rate of body shape
evolution. We estimate that rates of phenotypic evolution decreased by
more than an order of magnitude in the common ancestor of the Ctenotus
clade. These results provide evidence for a modal shift in phenotypic
evolutionary dynamics and demonstrate that major axes of morphological
variation can be decoupled from species diversification. More generally,
the Bayesian framework described here can be used to identify and
characterize complex mixtures of dynamic processes on phylogenetic trees.