EDWARDS LAB
Whole Plant Evolution
My general interests are plant diversity and evolution, population genetics, and plant geography. I have been integrating molecular, morphological, cytological and geographical information to examine phylogenetic relationships among morphologically diverse but genetically similar species of Cactaceae, mostly in tribe Trichocereeae. I am currently working on resolving phylogenetic relationships in the Portulacineae (which contains Cactaceae), with the aim of creating a framework for answering ecological and functional questions related to the evolution of the succulent life forms in this group.
My general interests reside in developing a better understanding of the relation between structure and function associated with water movement in plants in different environments. I am particularly interested in the hydraulics of roots and leaves, the evolution and functional consequences of diversity in leaf designs, the plasticity and adaptive variation in functional traits associated with water transport across environmental gradients, and the water relations of flowers and fruits. My current research is focused on exploring the evolution of leaf form and function within Viburnum, and the relations between leaf and stem traits and environmental variables.
I am generally interested in the genetic mechanisms that led organisms (and more specifically plants) to acquire new adaptive traits during the course of evolution. I appreciate all the methodological approaches that can address this question, and especially population genetics and phylogenetics. During my PhD studies, I adopted the evolution of C4 photosynthesis in the grass family (Poaceae) as a study system to explore numerous phylogeny-based issues, including the number and timing of independent C4 origins, the genetic basis of these convergent evolutions and the effect of the genetic background on the possibility of acquiring C4 photosynthesis. My projects in the Edwards lab will extend these investigations to larger taxonomic scales and other photosynthetic pathways (in particular CAM) to gain insights into the factors that increased the evolvability of complex traits during the diversification of plants.
My interests include plant systematics, desert floras, and the effects of rapid environmental change on ecosystems. After working on the systematics of desert Phacelia species for my master's thesis, I am looking forward to studying the ways that phylogenetic information can help predict plant responses to climate change. I will be investigating using plant functional traits and biogeochemistry to bridge the gap between phylogenetics and studies of global climate change.
I am interested in the evolution of plant form from a comparative and functionally-oriented point of view. My current research is focused on the evolution of succulent tissues (stems, leaves, and roots) in the plant clade Portulacineae. This group features much growth form diversity, from leafless stem succulents (core cacti and Didiereaceae), to succulent-leaved perennials (Anacampseros, Phemeranthus), to vines (Basellaceae), to tuberous forest understory herbs (Montia, Claytonia). I aim to understand the evolution of succulence as it relates to patterns of growth form and lineage diversification, ecology, and adaptation in this group. This includes questions such as, what did the ancestor of Portulacineae look like? Does the transfer of succulence between certain tissues tend to underly lineage success or adaptation to certain habitats? Is succulence a one-way street, or does it vary freely within lineages? What is the relationship between succulence and the CAM and C4 photosynthetic pathways, both of which occur in Portulacineae? These questions require incorporating information from across multiple levels, from the ecology of the whole plant to the water capacitance of individual cells. I am also planning, as a secondary but related project, to test a hypothesis about the role of trait lability in the evolution of morphological novelty (see Ogburn and Edwards 2009, AJB), by looking at the anatomy of unrelated lineages that have converged on a similar cactus-like (leafless stem-succulent) growth form.
email: mogburn at brown dot edu
I am interested in plant phylogenetics, comparative plant physiology, and plant responses to climate change. Since joining the Edwards lab as an undergraduate, I have worked on a series of projects including an honors thesis project on shifts in diversification rates in Poaceae. Recently, I have been expanding my thesis project to increase the sampling and simultaneously applying to PhD programs in plant evolutionary biology. I am also helping with the lab Viburnum project in measuring hydraulic traits with David Chatelet.
I am broadly interested in biogeography, ecology, and climate change. More specifically, I am interested in using ecological niche modelling to 1. describe the ecological space occupied by all known CAM and C4 species under current conditions and 2. predict future CAM and C4 species occurrences under different IPCC climate scenarios. I want to look for patterns in predicted range shifts on a species level and between phylogenetic groups, because I think it is important to ground ecology and biogeography in a phylogenetic context.
I am interested in studying plant ecology and sustainable agricultural science. I am currently working on my senior thesis in the Edwards lab that is a part of the Viburnum project. I am working with trichomes and trying to correlate their presence and density to the presence or absence of mutualistic mites on the surface of leaves of different Viburnum species.
Sam Schmerler, undergrad (2008-2011)
Kaya Schmandt, research tech (2008-2010)
Anne Williard, undergrad (2008-2009)
Cassidy Metcalf, undergrad (2007-2008)
research interests: Icelandic mosses; botanical illustration
research interests: Flora of Mt. Kinabalu; bananas