Susan Tremblay

General Interest

Dissertation Project

Liverworts of Sonoma

I am interested in liverwort phylogeny, especially in the origin and evolution of their unique oil bodies. These true, membrane–bound organelles are found in 90% of liverwort species and in all six back-bone lineages but in no other organisms. They have been lost secondarily in at least six clades in three of the main lineages. Liverwort oil bodies are surprisingly diverse in number, size, shape, color and other traits across taxa, yet are fairly uniform within each taxon, and are therefore reliable diagnostic characters that have been widely used taxonomically. Their exact function is not known.

Currently, I am mining the taxonomic literature and mapping oil body, morphological, ecological, and life cycle characters onto a recent liverwort phylogeny in order to gain insight into their evolution and diversification, and to develop testable hypotheses of oil body function based on evolutionary trends and patterns. Eventually I plan to test one or more of these hypotheses. I also plan to incorporate fossil data to help ascertain the plesiomorphic state of oil bodies and other characters.

I am interested in all aspects of early land plant evolution and the transition to land. I am especially interested in liverworts because they occupy an important position as the sister group to the rest of the land plants. 

Although all six of the main lineages of liverworts had diverged by the Permian, only a handful of fossil taxa are known from the Paleozoic. I would like to participate in renewed efforts to find fossil evidence of the earliest land plants and to incorporate fossil evidence into liverwort phylogenies in order to form a more complete picture of their early evolution.

I have a BFA from the School of Visual Arts in New York and have experience in experimental animation and macro and time-lapse photography that I would like to incorporate into my research, and into the study of plant movement and behavior.


stremblay at

Curriculum VitaeSusan_Tremblay_files/BIOGRAPHICAL%20SKETCH_Susan.pdf