My lab in collaboration with Ricardo Kriebel is using morphometric quantitative characters and shape analysis in a phylogenetic framework to assess the role of morphological change over time and in species diversification - see publications.

Moss sporophytes: we tested the hypothesis that evolution of sporangium (capsule) shape of the mosses, the second most diverse land plant lineage, has been driven by differing physiological demands of life in diverse habitats. We reconstructed ancestral sporangium shape and ancestral habitat on the largest phylogeny of mosses to date, utilized phylogenetic generalized least squares regression to test the association between habitat and sporangium shape, and examined the association between rate shifts in sporangium shape evolution and species diversification.

Rose, J. P., R. Kriebel, and K. J. Sytsma. Shape analysis of moss sporophytes (Bryophyta): insights into land plant evolution. American Journal of Botany 103: 652-662.

Myrtales pollen: We used morphometric and morphospace methods to evaluate pollen change in the order Myrtales using a time-calibrated, supermatrix phylogeny. We tested for conservatism, divergence, and morphological convergence of pollen and for correlation of niche variables and pollen size and shape. Myrtales pollen outlines were analyzed using elliptic Fourier methods, evaluated in a phylogenetic framework using PCA, and shifts examined using a new Ornstein-Uhlenbeck process. Shifts in Myrtales pollen morphology indicate conservatism but convergent shifts in shape but not size occurred in Myrtaceae and Onagraceae and are correlated to shifts in niche and biogeography.

Kriebel, R., M. Khabbazian, and K. J. Sytsma. 2017. Shifts in pollen shape and size in the order Myrtales using Ornstein-Uhlenbeck models. PLoS ONE 12(12): e0187228. https://doi.org/10.1371/journal.pone.0187228

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Salvia flowers & leaves: As part of the NSF funded project Collaborative Research: Phylogenetics, biogeography, and morphological evolution of an adaptive radiation - Salvia (Lamiaceae), our lab along with Dr. Bryan Drew are examining the evolution of floral features (corolla, anthers, style, stigma) in the context of area, biomes, and pollinator in a phylogenetic framework provided by Next Generation Sequencing.