Data from: Accelerated speciation in temperate Cannabaceae: The role of pre-adaptation, ecological opportunities, and niche divergence

Macroevolutionary processes underlying biome transitions and global
patterns of species diversity and ecological traits remain poorly
understood across many clades. We investigated tropical-to-temperate biome
transitions in Cannabaceae (the hemp family) to test the hypothesis that
pre-adaptive traits, particularly deciduous leaf habit, together with
ecological opportunities in temperate environments, promoted niche
divergence and elevated speciation rates. Using a well-resolved,
time-calibrated phylogeny representing approximately 70% of extant
Cannabaceae diversity, we integrated data on leaf duration, species
occurrences, and environmental variables. Phylogenetic comparative
analyses were employed to assess correlated evolution between
deciduousness and biome transitions, and to estimate speciation and niche
evolution rates across tropical, temperate, and widespread lineages. Our
results support correlated evolution between leaf habit and biome shifts,
with deciduous lineages exhibiting higher rates of transition from
tropical to temperate regions than evergreen lineages. Temperate lineages,
particularly those associated with a hidden state, showed increased
speciation rates relative to tropical lineages. In addition, niche
divergence occurred more rapidly in temperate than in tropical lineages,
especially along climatic dimensions related to temperature variability
and seasonal precipitation. These findings suggest that deciduousness
functioned as a pre-adaptive trait facilitating colonization of temperate
environments in Cannabaceae, and that the expansion of temperate biomes
since the Oligocene provided ecological opportunities that promoted
speciation through multidimensional niche divergence.