Global distribution and evolutionary transitions of angiosperm sexual systems

Angiosperm sexual systems are fundamental to the evolution and
distribution of plant diversity, yet spatiotemporal patterns in angiosperm
sexual systems and their drivers remain poorly known. Using data on sexual
systems and distributions of 68453 angiosperm species, we present the
first global maps of sexual system frequencies and evaluate sexual system
evolution during the Cenozoic. Frequencies of dioecy and monoecy increase
with latitude, while hermaphrodites are more frequent in warm and arid
regions. Transitions to dioecy from other states were higher than to
hermaphroditism, but transitions away from dioecy increased since the
Cenozoic, suggesting that dioecy is not an evolutionary end-point.
Transitions between hermaphroditism and dioecy increased, while
transitions to monoecy decreased with paleo-temperature when
paleo-temperature > 0 °C. Our study demonstrates the biogeography
of angiosperm sexual systems from a macroecological perspective, and
enhances our understanding of plant diversity patterns and their response
to climate change.