Brent Mishler

University of California, Berkeley

Research interests in my lab can be grouped into two main areas: (1) the theoretical basis of systematic and evolutionary biology, and (2) empirical studies of ecology, phylogeny, systematics, and development of green plants, especially mosses.

Theoretical studies include investigations of methods for phylogenetic reconstruction (with a recent emphasis on cladistic analysis of molecular data), and the relationship between development and evolution. One approach is to devise realistic mathematical models, and use these to understand intrinsic limits to cladistic analysis of molecular data, and to create realistic weighting algorithms to push back these limits.(e.g., methods for weighting restriction-site and protein coding gene data). I'm also interested in the meaning and application of the phylogenetic species concept, including applying recent ideas of rank-free phylogenetic classification to the species level.

Empirical studies in my lab are focused at several different scales of comparative biology. At a relatively "shallow" level in the tree of life, we study the biosystematics of mosses, most recently the tropical family Calymperaceae, funded by a large PEET grant from NSF. This is a combined research/training grant program which supports travel and research expenses as well as stipends for trainees at the postdoctoral, graduate, and undergraduate levels, all working on monographic studies in this evolutionarily interesting family of mosses. Studies involve extensive collecting and ecological studies in the field, comparative physiological measurements and culture experiments in the lab, and morphometric studies in the herbarium. Our first goal involved the overall phylogenetic definition of the family in relation to the other haplolepideous mosses. The most important finding so far is that part of what was considered another family, the Leucobryaceae (i.e., the Leucophanes - Arthrocormus - Exostratum group), is nested cladistically within the Calymperaceae. It appears that the strange Leucobryoid leaf morphology has evolved at least three independent times, and maybe four.

Another research program involves a series of studies on Syntrichia caninervis in the Mojave Desert, carried out in conjunction with Dr. Lloyd Stark of the University of Nevada, Las Vegas. This species exhibits several features of evolutionary interest, including extreme desiccation tolerance, very low frequency of sexual reproduction and highly skewed sex ratios (females are nearly 20 times more common than males). We are examining reproductive biology in relation to ecology in this extreme desert moss as well as in related, more temperate species, for comparative phylogenetic studies of ecology. In addition, I have collaborated for years with Dr. Melvin Oliver, USDA Lubbock, on studies of desiccation-tolerance in Syntrichia (Tortula)

At the "deepest" level, we are investigating phylogenetic relationships of the major groups of bryophytes and other land plants, using morphological, developmental, and ultrastructural characters as well as DNA sequence data. My lab sequences several genes in the chloroplast for comparative studies, including 16S rDNA, 23S rDNA, rps4, rbcL, trnL, and matK. We collaborate with a number of other labs on relationships of lineages at several levels throughout the green plants via participation in the Green Plant Phylogeny Research Coordination Group (GPPRCG, or "Deep Green"). I was one of three original co-PIs for this project, hosted the first GPPRCG meeting at UC Berkeley in 1995 (and have been involved as the primary organizer for several further meetings including the extensive activities at the International Botanical Congress in St. Louis in summer 1999), supervised the GPPRCG web site, and served as the Chair of the Executive Committee since it was formally established. Thus, I am well aware of the potential for enhancing one's own research with collaborative ties, and am looking forward to developing greater interactions with genomic biologists. From preliminary interactions, such the 2000 Genome Symposium I attended at February's AAAS meeting in Washington, DC., and the special meeting of the Bay Area Biosystematists on genomics and phylogenetics that Chris Somerville and I organized in May, I am convinced that the benefits of the proposed RCN will be mutual. Genome structure will provide a large number of high-quality phylogenetic markers of use to systematists, while on the other hand, the recently available robust phylogenies of green plants will allow significant advances in comparative studies of gene function of use to genomic biologists.