~ CURRENT PROJECTS ~
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My doctoral research uses multiple nuclear and chloroplast DNA in combination with phylogenetic strategies to reconstruct phylogenetic relationships within two subfamilies, the Ericoideae and the Cassiopoideae, which are sister clades within the plant family Ericaceae. Detailed examination of molecular and morphological evolution, as well as historical biogeography will be conducted in a phylogenetic framework.
		Kalmia microphylla--Photo: Z. Murrell
Phylogeny of the Subfamily Ericoideae: Tribe Circumscriptions and Relationships
The Ericoideae are comprised of approximately 20 genera that exhibit remarkable morphological diversity, which has made it difficult to understand evolutionary relationships. It is possible that either an ancient radiation or high rates of extinction have contributed to our difficulties understanding evolution within this complex clade. Historically, much of the Ericoideae have been recognized as a group based on overall similarity, and have been supported more recently by molecular studies and studies employing a cladistic approach. However, relationships among the five tribes within the subfamily have remained unclear.Particular uncertainty surrounds the membership of the tribe Phyllodoceae. This tribe’s circumscription changed with nearly every major treatment of the subfamily Ericoideae during the 20th century. Understanding the membership of the Phyllodoceae clade and the relationship of this group to other ericoid tribes will enable several other studies to be completed.
		Kalmia cuneata--Photo: E. Gillespie
Phylogeny of the Tribe Phyllodoceae: Evolution and Historical Biogeography
Once tribe membership and generic relationsihps are understood within the Phyllodoceae, a detailed examination of species relationships can be conducted. Likely tribe membership includes Phyllodoce (circumboreal), Kalmia (circumboreal), Elliottia (Japan, Northwest and Southeast U.S.), Epigaea (Eastern U.S.), Rhodothamnus (Southern/central Europe), Kalmiopsis (Oregon, U.S.) and possibly Bejaria (South America, Caribbean and Florida, U.S.), Bryanthus (Japan and Kamtschatka) and Ledothamnus (Guyana shield, South America). Biogeographical analyses using phylogenetic methods will be carried out on major clades. The most detailed work will be carried out within the genus Kalmia. Past phylogenetic analyses indicated that Kalmia also likely included two other genera (Leiophyllum and Loiseleuria). This result has been confirmed with further study, which has expanded the geographical distribution and morphological diversity of the genus. In addition to historical biogeographical analyses, this project will include a monograph of the genus Kalmia as it is now circumscribed.
		Phyllodoce empetriformis --Photo: D. Poindexter
Phylogeny of the Monotypic subfamily Cassiopoideae (Cassiope spp.): Identification of Major Clades
The Cassiopoideae are comprised of a single genus, Cassiope, which includes between 12 and 17 species, depending upon the authority. This genus is distributed circumboreally, and is most diverse in the mountainous regions of China. Unlike the Ericoideae, this group's species are quite similar in appearance, which presents a different set of problems than do widely divergent taxa. This project represents the first cladistic study in this interesting subarctic genus.
		Cassiope mertensiana--Photo: D. Poindexter
Virtual Phylogenetics Lab in Second Life Virtual Reality--Using New Technologies in Phylogenetic Training
Phylogenetic theory and application are an increasingly important component of all aspects of biology. However, few students receive excellent training in phylogenetics at the undergraduate level. Rather, they encounter phylogenetic ‘trees’ in textbooks, with little or no underlying understanding of how they are constructed. This appears to be due in part to the fact that phylogenetic theory is perceived to be rather diffuse, with a steep ‘learning curve.’ That is, one must attain a certain level of theoretical mastery before one can critically evaluate trees encountered. This can lead to 1) the sense that trees are ‘just trees’ and therefore are somehow not valuable, or 2) the sense that trees are ‘facts’ and not hypotheses or models of evolutionary relationships. Therefore a need exists for many different approaches to teach the next generation of biology students about phylogenetics. In recent years, virtual reality has emerged as a novel technology to present various kinds of instructional materials. The purpose of the proposed project is to build a virtual reality phylogenetics lab within Second Life. This project will provide a hands-on, flexible instructional environment for students to explore phylogeny reconstruction at their own pace, and with varying levels of challenge and complexity.