Floral Trait Evolution of Angiosperms on Pacific Islands

Contrary to expectations, flowers on Pacific islands are not universally smaller than those on the mainland. However, a closer look at specific archipelagos reveals that island taxa, including those of the UNESCO-listed Archipiélago de Revillagigedo, do evolve smaller flowers compared to their mainland counterparts. This divergence in flower size is not consistent across all plant families; some exhibit no change, while others show an increase in flower size on islands. The study analyzed 556 plant species and 136 phylogenetic contrasts, suggesting that ecological filtering rather than evolutionary divergence may explain the prevalence of small-flowered species on islands. This research challenges the notion of a general 'island syndrome' for floral traits, highlighting the complexity and context-dependency of floral evolution.

Hetherington-Rauth, M. C., & Johnson, M. T. J. (2020). Floral Trait Evolution of Angiosperms on Pacific Islands. The American Naturalist, 196(1), 87–100. https://doi.org/10.1086/709018