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Field of study
Plant evolution
Research interests
I am interesting broadly in the evolution of plants including their phylogenetic diversity, historical biogeography, and the evolution of morphological traits. I use phylogenetic hypotheses based on DNA sequence data to reveal patterns of and test hypotheses explaining these evolutionary processes. My dissertation work is focused on these processes at several levels within the genus Euphorbia.
I am currently building a phylogeny of Euphorbia subgenus Euphorbia, one of four subgenera in this giant genus of over 2000 species, and describing the anatomy and morphology of its stem-succulent members. This subgenus contains the majority of clades within the genus in which stem succulence has evolved, including the pencil-stem euphorbs of the Tirucalli group, the spiny crown-of-thorns group from Madagascar, the formerly segregate genera Monadenium and Pedilanthus, and the famous spine-shield euphorbs that are so often compared to Cactaceae as the classic example of convergent evolution. Using a phylogenetic framework of subgenus Euphorbia I plan to investigate the evolution of stem succulence by testing hypotheses of convergence, adaptation to drought, and the concerted evolution of traits, as well as investigate the nature of homoplasy in this complex trait. I am also reconstructing the historical biogeography of this clade in order to infer its geographic origins and its pattern of colonization that resulted in its current distribution throughout the tropics, and the continents of Africa and South America.
Another focus of my work is on the phylogeny and morphological evolution of the spine-shield euphorbs (section Euphorbia) native to Southern and Eastern Africa and tropical Asia. One hypothesis to explain the distribution and growth form evolution of this interesting clade states that there was a progression from leafy tropical trees toward increasingly succulent and drought tolerance shrubs and trees, finally resulting in dwarf geophytes as the group colonized increasingly arid habitats from South Asia through East Africa and finally to Southern Africa (Carter 1994). I plan to test this hypothesis by comparing ancestral growth forms reconstructed on a phylogeny of the section with its inferred historical biogeography.
Advisor
Paul Berry
Berry Lab web site
Euphorbia Planetary Biodiversity Inventory Project
News
International Institute Fellows
Cheers to these Ph.D. students doing research in the following countries: Diego Alvarado Serrano, Ecuador; Brian Dorsey, Spain and to George Livingston, Mexico, a biology undergraduate student with an EEB concentration. They each receive $2,000 to support their research or internships abroad.
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