Correlations between species richness and climate suggest non-random occupation of
environmental space and niche evolution through time. However, the evolutionary
mechanisms involved remain unresolved. Here, we partition the occupation of
environmental space into intra-and inter-clade components to differentiate a model based
on pure conservation of ancestral niches with higher diversification rates in the tropics, and
an adaptive radiation model based on shifts in adaptive peaks at the family level allowing …