Phylogenetic insights into the evolution of Saxifragales habitat shifts

Species-level phylogeny and habitat evolution data are applied to the hyper-diverse angiosperm clade Saxifragales to reveal that habitat shifts are very rare.

A phylogenetic tree for species of Saxifragales with a reconstruction of habitat evolution using SIMMAP (see key for colours). Representatives of major sub-clades are shown around the tree near the corresponding family name.

Saxifragales lineages are likely to remain rooted within their ancestral environment, and Rubio de Casas et al. demonstrate that in the exceptional cases where diversification has occurred, repeated colonization from other environments results in the transfer of lineages occurs across shrub land, tundra and rock cliff habitats. Desert and aquatic habitats host few lineages and are rarely colonized.