David Timerman, Ph.D.

Department of Ecology & Evolutionary Biology
University of Toronto
25 Willcocks Street
Toronto, Ontario, Canada
M5S 3B2

Office: Earth Science Building 2043
E-mail: david.timerman@mail.utoronto.ca

Degrees

Ph.D.                       Ecology and Evolutionary Biology (2021)
                                University of Toronto, Toronto, Canada

M.Sc.                       Biology (2013)
                                 Concordia University, Montreal, Canada

B.Sc. Hons.              Environmental Sciences (2010)
                                 Concordia University, Montreal, Canada

Current Position

Researcher, Department of Ecology & Evolutionary Biology, University of Toronto

Research Interests

I am interested in the ecology and evolution of plant reproductive systems and the biomechanical design of plants for reproduction. My research is cross-disciplinary, spanning mechanical engineering and biology, and tends to address mechanistic questions that can be investigated using models, wind tunnels and field studies.

For my PhD dissertation, I investigated mechanisms of pollen release in wind-pollinated flowering plants of the genus Thalictrum (Ranunculaceae), and the role of pollen release biomechanics, specifically turbulence-induced stamen vibrations, in driving transitions from animal to wind pollination. I am interested in pollen release because it is the critical first step in successful pollen dispersal by wind, but is probably costly for animal-pollinated species as a result of male gamete wastage.

I am also investigating the evolutionary ecology of Thalictrum pubescens, an ambophilous species (wind and insect pollination) which may represent an intermediate stage in the transition to wind pollination. Using T. pubescens, I have investigated selection on pollen release traits in the presence or absence of pollinators, mechanisms of sex ratio variation and the causes of male-biased sex ratio, and the effects of density and sex ratio on pollination success.

Publications

Timerman, D. & Barrett S.C.H. (2021). The biomechanics of pollen release: new perspectives on the evolution of wind pollination in angiosperms. Biological Reviews, in press.

Timerman, D. & Barrett S.C.H. (2020). Influence of local density and sex ratio on pollination in an ambophilous flowering plant. American Journal of Botany 107: 587-598. (pdf)

Timerman, D. & Barrett, S.C.H. (2019). Comparative analysis of pollen release biomechanics in Thalictrum: implications for evolutionary transitions between animal and wind pollination. New Phytologist 224: 1121-1132. (pdf)

Timerman, D. & Barrett, S.C.H. (2019). The spatial ecology of sex ratios in a dioecious plant: relations between ramet and genet sex ratios. Journal of Ecology 107: 1804-1816. (pdf)

Timerman, D. & Barrett, S.C.H. (2018). Divergent selection on the biomechanical properties of stamens under wind and insect pollination. Proceedings of the Royal Society B: Biological Sciences 285: 20182251. (pdf)

Timerman, D., Greene, D.F., Urzay, J. & Ackerman, J.D. (2014) Turbulence-induced resonance vibrations cause pollen release in Plantago lanceolata L. (Plantaginaceae). Journal of the Royal Society Interface 11

Timerman, D., Greene, D.F., Ackerman, J.D., Kevan, P.G. & Nardone, E. (2014) Pollen aggregation in relation to pollination vector. International Journal of Plant Sciences 175: 681-687.