Research
As an evolutionary ecologist, I would be interested in mentoring and collaborating on projects that consider evolutionary-ecological phenomena, relating processes and features of natural systems to the selective pressures that might influence them.
Research Interests
Mating system evolution in angiosperms
How does dioecy (separate male and female individuals) evolve in flowering-plant lineages?
How do some species retain (or regain) the presence of sterile reproductive structures (e.g., sterile-
pollen-containing anthers in female flowers)?
Evolution of pollen grain morphology
What patterns exist in of pollen grain morphology evolution?
How those patterns relate to shifts in plant-level traits that impact the specific selective pressures exerted
on features pollen grains (e.g., mode of pollen transmission)?
Is pollen grain morphology driven more by local ecology or by evolution within species lineages?
Current Research
Evolution of pollen morphology in Thalictrum
Natural Pollen Loads,
Thalictrum (Ranunculaceae)
Galdeen, T and RP Humphrey. 2022. Safety Nets Work Both Ways: the influence of paid sick leave on employee risk taking during the COVID-19 pandemic. Workplace Health and Safety Journal. link full text Infographic
Humphrey, RP and AG Ossip-Drahos 2018. Selection Imposed by Pollination Mode Minimally Influences Evolution of Pollen Morphology in Thalictrum (Ranunculaceae). International J Plant Sciences 179(9): 688-696. link DOI
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Humphrey, RP 2018. Sterile stamens do not enhance pollen receipt or seed set in females of the cryptically dioecious Thalictrum macrostylum (Ranunculaceae). J Torrey Botanical Society 145(1): 82- 90. link DOI
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Humphrey, RP 2016. Pollen heteromorphism is pervasive in Thalictrum (Ranunculaceae). Plant Systematics and Evolution 302(8):1171-1177. link DOI
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Penny, RH 2014. Sexual dimorphism in cryptically dioecious Thalictrum macrostylum.” International J Plant Sciences 175:794-802. link DOI
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Penny, RH, BR Montgomery and LF Delph 2010. Evidence for X-linkage of AP3A, a Paralog of the Y-linked MADS box Gene AP3Y. PLoS ONE 6(4):e18972. link DOI
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Penny, RH and JC Steven 2009. Sexual dimorphism in pollen grain size in cryptically dioecious Thalictrum macrostylum. Plant Systematics and Evolution 279:11-19. link DOI
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