Floral uniformity through evolutionary time in a species-rich tree lineage

Author(s)
Thais N. C. Vasconcelos, Marion Chartier, Gerhard Prenner, Aline C. Martins, Jürg Schönenberger, Astrid Wingler, Eve Lucas
Abstract

Summary Changes in floral morphology are expected across evolutionary time and are often promoted as important drivers in angiosperm diversification. Such a statement, however, is in contrast to empirical observations of species-rich lineages that show apparent conservative floral morphologies even under strong selective pressure to change from their environments. Here, we provide quantitative evidence for prolific speciation despite uniform floral morphology in a tropical species-rich tree lineage. We analyse floral disparity in the environmental and phylogenetic context of Myrcia (Myrtaceae), one of the most diverse and abundant tree genera in Neotropical biomes. Variation in floral morphology among Myrcia clades is exceptionally low, even among distantly related species. Discrete floral specialisations do occur, but these are few, present low phylogenetic signal, have no strong correlation with abiotic factors, and do not affect overall macroevolutionary dynamics in the lineage. Results show that floral form and function may be conserved over large evolutionary time scales even in environments full of opportunities for ecological interactions and niche specialisation. Species accumulation in diverse lineages with uniform flowers apparently does not result from shifts in pollination strategies, but from speciation mechanisms that involve other, nonfloral plant traits.

Organisation(s)
Department of Botany and Biodiversity Research
External organisation(s)
Federal University of Parana, Royal Botanic Gardens Kew, University College Cork
Journal
New Phytologist
Volume
221
Pages
1597-1608
No. of pages
12
ISSN
0028-646X
DOI
https://doi.org/10.1111/nph.15453
Publication date
02-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
106042 Systematic botany, 106008 Botany, 106012 Evolutionary research
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/floral-uniformity-through-evolutionary-time-in-a-speciesrich-tree-lineage(e23889bf-958a-4541-a7bc-baaa606caf7e).html