Denis Lynn

Head shot of Denis Lynn
College Professor Emeritus

Dr. Lynn began his career majoring in Marine Biology at the University of Guelph. He was inspired to study ciliates by the late Dr. Jacques Berger, University of Toronto, with whom he did doctoral research on the variations in cortical ultrastructure of colpodean ciliates. This work lead to his proposal of the structural conservatism hypothesis, which argued that cortical ultrastructural components were more highly conserved than “higher order” structures and that these cortical structures should provide a stronger phylogenetic signal for relationships. Applying this principle, Dr. Lynn and Dr. Eugene B. Small, University of Maryland, proposed a revised ciliate macrosystem, which recognized a number of new classes, based primarily on the ultrastructure of the microtubules associated with somatic basal bodies. In the mid-1980’s, Dr. Lynn’s laboratory began testing this proposed macrosystem using sequences of the small subunit rRNA gene. Recently, Dr. Lynn has collaborated on phylogenomic analyses to probe the deep topology of the ciliates and to resolve the phylogeny of problematic key genera. Dr. Lynn and his students have also published research on the ecology of marine, freshwater, and terrestrial ciliates and have described a number of new species using their quantitative protargol staining procedure and barcoding genes.

Dr. Lynn was Editor-in-Chief of The Journal of Eukaryotic Microbiology (1998-2012), is a Past-President (1993-1994) of the International Society of Protistologists, and is currently its Treasurer (2012-2018).


  • Lynn, D.H., Kolisko, M. 2017. Molecules illuminate morphology: Phylogenomics confirms convergent evolution among “oligotrichous” ciliates. International Journal of Systematic and Evolutionary Microbiology 67:3676-3682 [DOI 10.1099/ijsem.0.002060]
  • Lynn, D.H. 2008. The Ciliated Protozoa. Characterization, classification, and guide to the literature. 3rd Ed.Springer Verlag, Dordrecht. 605 p.
  • Lynn, D.H. 2004. Morphology or molecules: How do we identify the major lineages of ciliates (Phylum Ciliophora)? Europ. J. Protistol. 39(Year 2003): 356-364.
  • Lynn, D.H.  1981.  The organization and evolution of microtubular organelles in ciliated protozoa.  Biol. Rev. 56: 243‑292.
  • Lynn, D.H.  1976.  Comparative ultrastructure and systematics of the Colpodida.  Structural conservatism hypothesis and a description of Colpoda steinii Maupas, 1883.  J. Protozool. 23: 302‑314.