Jonathan Moore, PhD Completed August 2017

I study the causes of sexual dimorphisms in dioecious plants and their subsequent consequences on adult sex ratios.  While the causes of sex ratio bias is not well understood, adult sex ratios vary across and within major clades of land plants (from all male to all female populations) and are likely due to sexual dimorphisms.  These sexual dimorphisms may have evolved because of the differences in sex function between male and female plants.  In the non-vascular plants, female sex ratio bias is more common than male bias.  I am interested in understanding why this is the case since it would seem that females have a higher cost of sexual reproduction due to offspring production. The higher female cost of reproduction is assumed to cause higher mortality of females in woody angiosperms, but it is becoming increasingly clear that some angiosperms (herbaceous and clonal) have female biased adult sex ratios.  The number of bryophyte species exhibiting female bias and the increasing awareness of female bias in angiosperms makes female biased dioecious bryophytes good model systems.  I use the common dioecious sidewalk moss, Bryum argenteum, as a model to determine the underlying causes of female-biased sex-ratios. 

Rose Marks, PhD candidate

I am investigating the ecological patterns and genetic mechanisms of dehydration tolerance in the tropical liverwort Marchantia inflexa. My interest in this topic stems from an understanding that organisms are threatened by global climate change. With increasing variation in annual rainfall species are forced to endure prolonged periods of dryness and drought. Thus, adaptations that allow organisms to survive in an increasingly dry and unpredictable environment are necessary for species persistence. Furthermore, understanding the basic mechanisms of dehydration tolerance can provide insight into methods for developing stress tolerant crops that will remain productive in the changing environment. My work addresses the mechanism of dehydration tolerance by targeting fine scale differences in tolerance within a single species. In my spare time I can usually be found climbing rocks, training for climbing rocks, or talking about climbing rocks. I also love baking cakes. 


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D. Nicholas McLetchie Ph.D., Phone: 859-257-6786, Fax: 859-257-1717,  Email:
Department of Biology, 101 Morgan Building, University of Kentucky, Lexington KY 40502-0225
Juliana Silva e Costa, Visiting Scholar

I am a Brazilian graduate student, Federal University of Juiz de Fora, and I’m a visiting the University of Kentucky during the period of July to December 2017. I am interested in study liverwort’s morphology, ecology and physiology, connecting these traits with their habitat and environmental requirements. In McLecthie laboratory I am studying population sex ratio variation and physiological characteristics of a leafy liverwort.