David Timerman, Ph.D. candidate

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

Office: Earth Science Building 2042
E-mail: david.timerman@mail.utoronto.ca

David Timerman
David at, The cirque along King’s Throne trail,
Kluane National Park & Reserve, Yukon.

Degrees

M.Sc. Biology, Concordia University, Montreal QC.
Thesis title: Pollen clumping and release mechanisms in wind pollinated plants. (2013)

B.Sc. (Hons.) Environmental Sciences, Concordia University, Montreal QC.
Thesis title: Pollen concentration and seed set in Picea mariana (black spruce). (2010)

Current Position

Ph.D. candidate Department of Ecology & Evolutionary Biology, University of Toronto
Thesis title: Mechanistic studies on the evolution of wind pollination

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 am investigating 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.

DT in Boreal forest
The last field site

Peer Review

I have peer-reviewed for 9 academic journals including Evolution, Journal of Ecology and New Phytologist, and was recognized as a top reviewer for Evolution in 2018. I am happy to review manuscripts on topics related to plant biomechanics, sex allocation, pollination ecology and reproductive transitions.

Publications

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. (pdf)

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 (pdf)