Understanding plant evolution, or evolution in general, requires research in a diversity of disciplines. Research in the Baum lab spans many of these approaches. The philosophy is to support individuals from diverse disciplinary backgrounds so they can learn from each other while pursuing personally fulfilling research programs. Below is a summary of some of the ongoing research, organized by discipline.
We have had a long-standing interest in the phylogeny of Malvaceae s.l., and especially the Malvatheca clade, which includes the traditional families Bombacaceae and Malvaceae. A second emerging theme is the use of molecular markers to study "species" maintenance. To this end we use nuclear gene genealogies to explore genealogical discordance within and among closely related species. In collaboration with Statistics colleagues, Cecile Ané and Bret Larget, we have developed Bayesian concordance analysis, a new method for using multilocus sequence data to quantify genealogical discordance within genomes and to estimate the proportion of the genome for which a given clade is true. Also in the area of theory, David Baum continues to work on the concepts of species, homology, and phylogenetic nomenclature.
2) Evo-Devo: Evolutionary Developmental Genetics
The Baum lab has endeavored to develop a number of experimental systems in which one can study the genetic basis of morphological evolution above the species level. A number of projects started in the lab are now continuing elsewhere. Current students are continuing research in the following areas: the molecular basis of variation in the presence and position of petal spots in Clarkia gracilis, the molecular basis of stellate trichomes in Physaria, and the evolution of rosette flowering in several lineages of Brassicaceae.
A new approach being explored in the laboratory, is transgenomics. The basic strategy is to isolate large random fragments of genomic DNA from a donor species and introduce them into a recipient species (in our case A. thaliana) by transformation. The resultant transgenic lines are then screened for phenotypes of interest: interesting developmental defects and/or traits that resemble the donor species.