Evidence for an evo-devo-derived hypothesis on three-dimensional flower shape modularity in a tropical orchid clade

Author(s)
Silvia Artuso, Alexander Gamisch, Yannick M. Staedler, Jürg Schönenberger, Hans Peter Comes
Abstract

Abstract Covarying suites of phenotypic traits, or modules, are increasingly recognized to promote morphological evolution. However, information on how modularity influences flower diversity is rare and lacking for Orchidaceae. Here, we combine high-resolution X-ray computed tomography scanning with three-dimensional geometric morphometrics and phylogenetic comparative methods to test various hypotheses about three-dimensional patterns of flower evolutionary modularity in Malagasy Bulbophyllum orchids and examine rates and modes of module evolution. Based on the four evolutionary modules identified (i.e., sepals, lateral petals, labellum + column-foot, and column-part), our data support the hypothesis that both genetic-developmental and functional adaptive factors shaped evolutionary flower trait covariation in these tropical orchids. In line with ?evo-devo? studies, we also find that the labellum evolved independently from the rest of the petal whorl. Finally, we show that modules evolved with different rates, and either in a neutral fashion (only column-part) or under selective constraints, as likely imposed by pollinators. Overall, this study supports current views that modular units can enhance the range and rate of morphological evolution.

Organisation(s)
Department of Botany and Biodiversity Research
External organisation(s)
Paris-Lodron Universität Salzburg
Journal
Evolution
Volume
76
Pages
2587-2604
No. of pages
18
ISSN
0014-3820
DOI
https://doi.org/10.1111/evo.14621
Publication date
09-2022
Peer reviewed
Yes
Austrian Fields of Science 2012
106008 Botany, 106012 Evolutionary research, 106042 Systematic botany
Keywords
ASJC Scopus subject areas
General Agricultural and Biological Sciences, Genetics, Ecology, Evolution, Behavior and Systematics
Portal url
https://ucrisportal.univie.ac.at/en/publications/66059c50-71c3-4c35-9474-2a3c9751cf9f