The evolution of flowering plants through pollen

Paper presents novel morphometric approach to studying the evolution of pollen in a large order of flowering plants

Data resources used via GBIF : 1,896,305 species occurrences
Fuchsia excorticata
Tree fuchsia (Fuchsia excorticata) by vhealey via iNaturalist. Photo licensed CC BY-NC 4.0.

The study of flowering plant evolution through phylogeny has often included analyses of pollen. Mostly limited to traditional morphometric methods, pollen studies often bin traits and treat features like shape and size using discrete categories.

In this paper, authors present a novel approach to pollen evolution study based on quantitative size and shape variables. They used images of Myrtales pollen grains from two different angles to measure length and width of the grains, while analyzing outlines of the shape and converting these into elliptic transformations used for comparisons.

They analyzed pollen size and shape in a phylogenetic context and found significant differences among Myrtales families when comparing both shape and size. To test for linkages betwen pollen features and climate, the authors used GBIF-mediated occurrences and found that pollen shape was correlated with the mean latitude of a species’ distribution.

The novel morphometric approaches presented in the study prove useful for taxonomic identification and phylogenetic placement of as yet unknown pollen fossils.

Link to original article

Kriebel R, Khabbazian M and Sytsma KJ (2017) A continuous morphological approach to study the evolution of pollen in a phylogenetic context: An example with the order Myrtales. PLOS ONE. Public Library of Science (PLoS) 12(12): e0187228. Available at: https://doi.org/10.1371/journal.pone.0187228.