Jonathan D.S. Witt

Undergraduate Advisor (Environmental Science, Ecology)

Biology Field course Coordinator

2011 Excellence in Science Teaching Award (ESTA) Recipient
Bachelor of Science (BSc), Master of Science (MSc), Doctor of Philosophy (PhD) Guelph

Email: jwitt@uwaterloo.ca

Telephone: (519) 888-4567 ext. 35951

Office: Biology 2 252A

Research interests

My research is focused on the application of molecular markers to address questions related to the ecology and evolution of aquatic organisms. A central theme that is currently being addressed in my lab concerns the reasons for, and consequences of disparities between rates of evolution at the molecular and morphological levels. To address these issues, we employ both population and species level comparative approaches. The lab is also engaged in research related to conservation, and the use of molecular methods for the diagnosis of species boundaries.

Selected publications

• Millette, K.L., Xu, S, Witt, J.D.S, Cristescu, M.E. (2011) Pleistocene-driven diversification in the freshwater zooplankton: Patterns of glacial refugia, postglacial re-colonization, and cryptic speciation in Leptodora kindtii. Limnology and Oceanography 56: 1725-1736.
• Witt, J.D.S., Taylor, E.B. and Zemlak, R. (2011) Phylogeography and the origins of range disjunctions in a north temperate fish, the pygmy whitefish (Prosopium coulterii), inferred from mitochondrial and nuclear DNA sequence analysis. Journal of Biogeography 38: 1557-1569.
• Taylor, E.B., Gow, J., Witt, J.D.S, and Zemlak, R. (2011) Connectivity among populations of pygmy whitefish (Prosopium coulterii) in north western North America inferred from microsatellite DNA analyses. Canadian Journal of Zoology 89: 255-266.
• Adamowicz, S.J., Menu-Marque, Halse, S.A., S., Topan, J.C., Zemlak, T.S., Hebert, P.D.N, Witt, J.D.S. (2010) The evolutionary diversification of the Centropagidae (Calanoida, Copepoda): a history of habitat shifts. Molecular Phylogenetics and Evolution, 55:418-430.
• Rios, P.P, Adamowicz, S.J. and Witt, J.D.S. (2010) The aquatic fauna of the driest desert on Earth: first report of the crustacean fauna of the Loa River (Atacama Desert,  Antofagasta region, Chile) Crustaceana 83: 257-266.
• Adamowicz, S.J., Colbourne, J.K., Hebert, P.D.N. and Witt, J.D.S. (2009) The scale of divergence: A phylogenetic appraisal of intercontinental allopatric speciation in a passively dispersed freshwater zooplankton genus. Molecular Phylogenetics and Evolution 50: 423-436.
• Gregory, T.R. and Witt, J.D.S. (2008)  Population size and genome size in fishes: a closer look. Genome 51: 309-313.
• Witt, J.D.S., Threloff, D.L. and Hebert, P.D.N. (2008) Genetic zoogeography of the Hyalella azteca species complex in the Great Basin: rapid rates of molecular diversification in desert springs. In Late Cenozoic Drainage History of the Southwestern Great Basin and Lower Colorado River Region: Geologic and Biotic Perspectives (eds Hershler R, Reheis M, Miller D), Geological Society of America Special Paper 439, 103-114.
• Väinölä, R., Witt, J., Grabowski, M., Bradbury, J., Jazdzewski, K. and Sket, B. (2008) Amphipoda (Crustacea): An account of diversity in world continental waters. Hydrobiologia 595: 241-255.
• Witt, J.D.S., Threloff, D.L. and Hebert, P.D.N. (2006) DNA barcoding reveals extraordinary cryptic diversity in an amphipod genus: implications for desert spring conservation. Molecular Ecology 15: 3073-3082.
• Cristescu, M.E.A., Witt, J.D.S., Grigorovich, I.A., Hebert, P.D.N. and MacIsaac, H.J. (2004) Dispersal of the Ponto-Caspian amphipod Echinogammarus ischnus: invasion waves from the Pleistocene to the present. Heredity 92:197-203.
• Witt, J.D.S., Blinn, D.W. and Hebert, P.D.N. (2003) The recent evolutionary origin of the phenotypically novel amphipod Hyalella montezuma offers an ecological explanation for morphological stasis in a closely allied species complex. Molecular Ecology 12: 405-413.
• Hebert, P.D.N., Witt, J.D.S. and Adamowicz, S. (2003) Phylogeographic patterning in Daphnia ambigua: regional divergence and continental cohesion. Limnology and Oceanography 48: 261-268.
• Cristescu, M.E., Hebert, P.D.N., Witt, J.D.S., MacIsaac, H.J. and Grigorovich, I.A. (2001) An invasion history for Cercopagis pengoi based on mitochondrial gene sequences. Limnology and Oceanography 46: 224-229.
• Witt, J.D.S. and Hebert P.D.N. (2000) Cryptic species diversity and evolution in the amphipod genus Hyalella in central glaciated North America: a molecular phylogenetic approach. Canadian Journal of Fisheries and Aquatic Sciences 57: 687-698.
• Ardelli, B.F., Witt, J.D.S. and Woo, P.T.K. (2000) The identification of glycosomes and metabolic end products in pathogenic and nonpathogenic strains of Cryptobia salmositica. Diseases of Aquatic Organisms 42: 41-51.
• Dermott, R., Witt, J., Um, Y.M. and Gonzalez, M. (1998) Distribution of the Ponto-Caspian amphipod Echinogammarus ischnus in the Great Lakes and replacement of native Gammarus fasciatus. Journal of Great Lakes Research 24: 442-452.
• Hopcroft, R.R., Roff, J.C., Webber, M.K. and Witt, J.D.S. (1998) Zooplankton growth rates: the influence of size and resources in tropical marine copepodites. Marine Biology 132: 67-77.
• Witt, J.D.S., Hebert, P.D.N. and Morton, W.B. (1997) Echinogammarus ischnus: another crustacean invader in the Laurentian Great Lakes basin. Canadian Journal of Fisheries and Aquatic Sciences. 54: 264-268.