Comparative phylogeography of the Rocky Mountains

My love for alpine flora began in the Rockies, so naturally I have found a way to do research in an area I grew up with an have a connection with the flora.

I am currently investigating the phylogenography of two Rocky Mountain plants: Polemonium pulcherrimum & Picea engelmannii. Both species are common in subalpine forests throughout the Rockies and other Western mountain regions. There appears to be a close association between the two species as well (i.e., the almost always co-occur).

My research interests started as an undergraduate where I help investigate the conservation genetics of Spiranthes diluvialis (Orchidaceae) in the foothill of the Colorado Front Range. Later, as a master’s student at San Francisco State, I worked on the phylogenetic systematics of Linanthus (Polemoniaceae). Over the past five years, my lab has started work on Symphoricarpos (ca. 15 species), or the snowberries. This group provides an excellent model for the study of western Northern Hemisphere biogeography, with most of the species of Symphoricarpos restricted to the mountainous regions of the western United States. The group is ideal for testing many hypotheses concerning the origin and diversification of this unique flora. In addition, Symphoricarpos displays a classic Northern Hemisphere disjunction with one species in China and the rest in the New World. A recent phylogeny for the group (Bell, 2010) based on chloroplast and several nuclear markers showed little support for the relationships among species of Symphoricarpos, most likely due to the short time frame in which these taxa diversified. Because of this lack of resolution using traditional molecular markers, my lab has begun using “Next Generation” sequencing methods to identify potentially hundreds of new phylogenetic markers for this group. These new markers, analyzed with newly proposed gene tree/species tree methodologies (e.g., BUCKy, BEST & *BEAST), will go a long way toward resolving the phylogenetic relationships within this group. Understanding the phylogeny of this group will aid in our understanding of global biogeographic patterns. The work on Symphoricarpos is part of a larger phylogenetic project in collaboration with Michael Donoghue (Yale University). I have recently submitted an NSF Systematic Biology grant proposal for this project.

More recently, my lab has also initiated several projects aimed at understanding diversification patterns in western North America, and the California Floristic Province (CFP) in particular. One such project involves Polemoniaceae (Bell et al. In prep.). For this project we have compiled a nearly complete species-level phylogeny for the group. This large tree is allowing us to test numerous hypothesis concerning shifts in ecology and diversification, floral morphology, pollination biology, and habit in a comparative framework. In addition, we have initiated a pilot study (Bell, In prep), to investigate the phylogeography of he high elevation flora across the western United State (Rocky Mountains, Sierra Nevada, Cascades). Both of these projects involve the development of bioinformatic “pipelines” to harvest data from public databases in order to generate large datasets (e.g., GenBank, GBIF, California Plant Consortium). These pipelines have provided an effective way of acquiring preliminary data and have helped use target where the collection additional data (genetic, ecological, and morphological) should be targeted. The logical next step for each of these projects is to corroborate much of this public data with detailed observations in the field and from museum collections.

About Me

I am an evolutionary biologist interested in phylogenetics, plant systematics, divergence time estimation, and biogeography