Skip to main content
Dryad logo

Stigma shape shifting in sages (Salvia: Lamiaceae) – hummingbirds guided the evolution of New World floral features

Citation

Kriebel, Ricardo et al. (2021), Stigma shape shifting in sages (Salvia: Lamiaceae) – hummingbirds guided the evolution of New World floral features, Dryad, Dataset, https://doi.org/10.5061/dryad.v15dv41v1

Abstract

A fundamental question in evolutionary biology is how clades of organisms exert influence on one another. The evolution of the flower and subsequent plant/pollinator coevolution are major innovations that have operated in flowering plants to promote species radiations at a variety of taxonomic levels in the Neotropics. Here we test the hypothesis that pollination by Neotropical endemic hummingbirds drove the evolution of two unique stigma traits in correlation with other floral traits in New World Salvia (Lamiaceae). We examined morphometric shapes of stigma lobing across 400 Salvia spp., scored presence and absence of a stigma brush across Salvia, and used a suite of phylogenetic comparative methods to detect shape regime shifts, correlation of trait shifts with BayesTraits and phylogenetic generalized least square regressions, and the influence of scored pollinators on trait evolution using OUwie. We found that a major Neotropical clade of Salvia evolved a correlated set of stigma features, with  a longer upper stigma lobe and stigmatic brush, following an early shift to hummingbird pollination. Evolutionary constraint is evident as subsequent shifts to bee pollination largely retained these two features. Our results support the hypothesis that hummingbirds guided the correlative shifts in corolla, anther connective, style and stigma shape in Neotropical Salvia, despite repeated shifts back to bee pollination. 

Methods

This data set contains the outlines, phylogenies and R code used in the morphometric and comparative analyses described in the paper "Kriebel, R., Drew, B.T., Gonzalez-Gallegos, J.G., Celep, F., Antar, G.M., Pastore, J.F.B., Uria, R., Sytsma, K.J. 2021. Stigma shape shifting in sages (Salvia: Lamiaceae): hummingbirds guided the evolution of New World floral features. Botanical Journal of the Linnean Society". The study investigates the evolution of stigma shape in the genus Salvia and close relatives. 

To calculate the shape of the stigmas, outlines of stigmas were used in morphometric analyses. These outlines are provided in this repository in the "Outlines folder". This folder includes the outlines both as .jpg files as well as files imported into R and landmarked for further analysis as described in the paper and saved. The raw files are provided in case researchers would like to expand our study in the future or use in a similar study. The saved ones as a .rds file are imported and used downstream as explained in the "Usage Notes" below.

The outlines of the stigmas were obtained both from illustrations available in the taxonomic literature as well as additional specimens scanned with a flatbed scanner as described in the paper. The outlines were then imported into R and analyzed using elliptic Fourier analysis. The stigma scores were then matched to the phylogenies from a previous study for downstream analyses. The previous study that produced these phylogenies is: "Kriebel, R., Drew, B.T., Drummond, C.P., González-Gallegos, J.G., Celep, F., Mahdjoub, M.M., Rose, J.P., Xiang, C.L., Hu, G.X., Walker, J.B., Lemmon, E.M., Lemmon, A.R., and Sytsma K.J. 2019. Tracking the temporal shifts in area, biomes, and pollinators in the radiation of Salvia (sages, Lamiaceae) across continents: leveraging Anchored Hybrid Enrichment and targeted sequence data. American Journal of Botany 106: 573-597."
 

Usage Notes

An Rmd file with code to reproduce the analysis in R is included. 

Funding

National Science Foundation, Award: DOB-1046355

National Science Foundation, Award: DEB-1655606

National Science Foundation, Award: DEB-1655611