Macroevolution: speciation, disparity, & the dynamics of evolutionary radiations

Macroevolution is broadly defined as evolution at or above the species level. My current research in this field surrounds the origin of major lineages, their morphological diversification, and the ecological context of large-scale evolutionary radiations. My work has primarily focused on two issues: (1) quantifying patterns of global biodiversification, particularly during the Paleozoic, and (2) testing process-based models of trait evolution to estimate rates of evolutionary change and changes in morphological diversity associated with major evolutionary radiations.

A current focus is to better understand the biological and geological processes underlying the Ordovician Radiation of marine animal life. The Ordovician Radiation was the largest increase in species diversity in the history of life and represents a key interval in Earth history marked by coordinated biological and geological change, including shifts in ecosystem complexity, climate, and atmospheric oxygen.

I have recently begun work on project combining paleontological data with molecular phylogenetics to better understand the origin and Mesozoic-Recent diversification of crown-group Crinoidea (Echinodermata). In particular, I am interested in the whether the timing of this radiation is linked with the aftermath of the end-Permian mass extinction and the extent morphological diversity was shaped by “empty” marine ecosystems.

The overarching goal of my macroevolution research is to help clarify important questions in modern evolutionary theory where geological data are key. Major questions include (but are not limited to) (i) dissecting relationships between Earth-system change (e.g., atmospheric O2), ecological opportunity, adaptations, and evolutionary radiations, (ii) the origin, evolution, and persistence of clade-wide adaptive zones, and (iii) understanding how global change events modify the structure of adaptive landscapes.

Representative publications

Thuy, B., Eriksson, M.E., Kutscher, M., Lindgren, J., Numberger-Thuy, L.D., and  Wright, D.F., Miniaturization during a Silurian environmental crisis generated the modern brittle star body plan. Communications Biology (2022)

Wright, A.M, Wagner, P.J., and Wright, D.F., 2020, Testing character-evolution models in phylogenetic paleobiology: a case study with Cambrian echinoderms. In review for Elements in Paleontology, preprint available at: EcoEvoRxiv. doi:10.32942/, posted here

Cole, S.R., Wright, D.F., and Ausich, W.I., 2019, Phylogenetic community paleoecology of one of the earliest complex crinoid faunas (Brechin Lagerstätte, Ordovician). Palaeogeography, Palaeoclimatology, Palaeoecology, 521: 82-98.

Wright, D.F., 2017, Phenotypic innovation and adaptive constraints in the evolutionary radiation of Palaeozoic crinoids. Scientific Reports, 7(1), 13745. doi:10.1038/s41598-017-13979-9.

Wright, D.F. and Toom, U., 2017 New crinoids from the Baltic region (Estonia): fossil tip-dating phylogenetics constrains the origin and Ordovician–Silurian diversification of the Flexibilia (Echinodermata). Palaeontology, 60: 893-910.

Stigall, A.L., J.E. Bauer, A.R. Lam, and D.F. Wright. 2016, Biotic immigration events, speciation, and the accumulation of biodiversity in the fossil record. Global and Planetary Change, 148: 242-257.

Wright, D.F. and A.L. Stigall, 2013, Geological drivers of Late Ordovician faunal change in Laurentia: investigating links between tectonics, speciation, and biotic invasions. PLoS ONE, 8(7): e68353. doi:10.1371/journal.pone.0068353