Research Introduction

Our research is centered on the processes and patterns involved in the evolution and diversification of plants, especially the monocots. We use a phylogenetic framework to test hypotheses of morphological evolution and to analyze temporal and spatial patterns of plant speciation and diversification. The use of systematics in comparative biology is emphasized. Areas of focus are on the evolution of development, comparative genomics and the genetics of interspecies interactions.

 
Topics that we are currently investigating include:
  • Phylogenetics, species-level systematics, and evolution of Monocot lineages, including the tropical gingers (Zingiberales), Nolina (Ruscaceae) and California Allium.
  • Floral development and evolution of the Zingiberales.
  • Evolution of plant traits, including pollination syndromes, thermogenesis and wood anatomy associated with the liana habit.
  • Population genetics and phylogeography of mexican and californian plant lineages (Nolina, Calochortus).
  • Development of Comparative Analysis Software and Visualization (ArborWorkflows.com).
 

 

Plant Systematics and Evolution

Lab members are involved in various systematics project, many focused on monocot lineages (Heliconia, Costaceae, Zingiberaceae, California Allium & Calochortus) but also in other systems with interesting evolutionary novelties (e.g. Evolution of liana habit and associated changes in the vascular cambium in Sapindaceae (Paullinieae); Evolution of underground starch storage in geophytic monocots).

Floral Development and Evolution

Due to the natural diversity of floral forms, the Zingiberales provide an ideal model system to test the role of candidate floral development genes in the formation of diverse morphologies found in these plants. We are investigating the role of identified genes important in floral development in the evolution of development and the origin of novel floral structures (such as the labellum) within the flowers of Zingiberales. Techniques include RNA-Seq and transcriptome analysis, in situ hybridization and RT-PCR to analyze gene expression patterns of candidate genes during defined stages of early and late stage floral development, and Virus Induced Gene Silencing (VIGS) to create effective gene knock-downs. To date we have projects focusing on CYC-like genes and floral symmetry (Bartlett and Specht 2011), the PISTILLATA/GLOBOSA-like gene lineage of B-class genes (Bartlett and Specht 2010), AP3/DEF lineage of B-class genes (A. Almeida), AGAMOUS lineage of C-class genes (A. Almeida), and the SEP genes (R. Yockteng et al MBE). Recent work is focusing on the role of Gene Regulatory Networks and miRNAs in mediating development through symmetry, polarity and floral identity regulatory networks.

Molecular Mechanisms Underlying Trait Evolution

Plants have evolved certain traits that enable them to survive and diversify over time. The history of genetic and genomic changes that have led to or even enabled trait evolution is one of the major focuses of the lab. Currently, graduate students are investigating the genetic mechanisms underlying two very interesting traits that have evolved multiple times in land plants: thermogenesis and carnivory.

Species Diversity and Key Innovations

The role of pollination syndromes as key innovations in plant speciation and diversification is a subject of much interest and controversy. Increasing amounts of genomic data are available for not only determining relationships among organisms, but also investigating the time frame in which these organisms have evolved. As sophisticated molecular-clock algorithms are used to accurately estimate ages of organismal speciation and diversification, robust statistical techniques have been developed to estimate absolute rates of diversification for independent lineages. Diversification rates are then compared with physical, physiological, or ecological attributes of organisms to investigate the role of any particular acquired characteristic (key innovation) on subsequent rates of speciation.

Biogeography and Phylogeography

The lab is interested in biogeographic studies at the species and population-level, using molecular data and ecological niche modeling to investigate distributional patterns within species and species complexes. Such studies can be combined with analyses of range reductions and genetic diversity among populations in order to provide information for informed conservation planning at the species level and to study the origins of crop plants to help direct genomic research of crop development.

Contribute to our Mission!

If you are interested in contributing to the mission of our research program, its easy! Just follow the link http://givetocal.berkeley.edu/fund/?f=FU0970000 and support us in whatever way possible. We'd love to hear from you, and any bit helps us obtain our research goals of contributing to a global understanding of plant biodiversity.

Undergraduate Research Opportunities

Undergraduates are encouraged to apply to work in the lab via URAP or SPUR. Students receive training in plant evolutionary biology by working on a mentored project with graduate students and postdoctoral researchers in the lab, but can eventually can take on an independent project or honor's thesis project that fits their interests in plant developmental genetics, evolutionary biology, systematics or biogeography.