The evolution of form and function in flowering plants
Systematics and Evolution of the Spiral Gingers
My research with the "spiral gingers" involves utilizing a phylogenetic framework to investigate molecular evolution, floral development, and the historical biogeography of the pan-tropical family Costaceae. This family forms an easily recognizable clade within the Zingiberales, distinguished from other families in the order by its characteristic one-sided spiral phyllotaxy and its floral design, featuring 5 infertile stamens fused to form a petaloid labellum. Costaceae presently consists of about 95 species which until recently were placed in four genera: Costus, Tapeinochilos, Dimerocostus, and Monocostus. Recent systematic and developmental studies have led to a novel understanding of evolution within the family and have resulted in the description of three new genera (Chamaecostus, Cheilocostus and Paracostus) to accommodate the phylogenetic diversity of the Costaceae.
Costus lucanusianus, a monocot with a bee pollination syndrome.
The diverse floral morphology found in the family Costaceae makes this group an ideal model system for addressing a number of evolutionary questions. Research on this group revolves around four integrated components:
- developing a robust phylogeny using molecular and morphological characters and revising the taxonomy of the lineage,
- investigating floral pattern formation using taxa which encompass a range of morphological and phylogenetic diversity,
- conducting comparative studies of floral development characters in order to explore the association between pollination syndrome, species diversity and rates of diversification, and
- comparing the age of phylogenetic diversification with the geological record to interpret the biogeographic history of this group.
Costus pulverulentus, a monocot with a hummingbird pollination syndrome.
Evolution and Diversification of Monocots:
Evolution and Floral development in Zingiberales
My lab has several projects focusing on systematics and floral development in the order Zingiberales (tropical gingers). Programs looking at evolutionary patterns in the Heliconiaceae (Heliconia) and Zingiberaceae (Alpinioideae, Zingiberoideae) are underway. The results of these systematic studies are interpreted with respect to pollination biology, floral development, biogeography and molecular evolution at the ordinal level. Ongoing studies also include the evolution of floral development in the ginger order.
Evolution and edaphic variation in the Milla complex
In collaboration with Dr. Victoria Sosa at INECOL, Xalapa, Mexico, we are investigating the systematic relationships of plants in the Milla complex of the monocot family Themidaceae (Asparagales). This includes genera Milla, Petronymphe, Jaimehintonia, Dandya and Bessera from Mexico as well as several groups from California. This project is funded by the UC MEXUS program.
A Milla from Mexico.
Evolution and origin of California Alliums
With funding from the Heckard Fund, we are investigating the evolutionary position of California alliums (wild onions) within the worldwide genus (Allium). Preliminary results indicate that the California species may not be monophyletic and suggest an interesting history of adaptive radiation onto specialized serpentine soils.
Allium brevistylum from Utah and Colorado.
Phylogeography and Species Conservation
I am interested in biogeographic studies at the population-level, using molecular data 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. Current projects in this area include Pollination, Gene flow and Population genetics of the Mexican cycad genus Dioon.
Dioon purpusii in Oaxaca, Mexico. Photo courtesy of the Palm & Cycad Societies of Florida, Inc. web page (www.plantapalm.com).
A.D. Poulsen and C.D. Specht. 2010. A new species of Costaceae from Borneo. Gardens Bulletin Singapore 62 (1): 143-150. PDF
C. Sass and C.D. Specht. 2010. Phylogenetic estimation of the core Bromeliads with an emphasis on the genus Aechmea (Bromeliaceae). Molecular Phylogenetics and Evolution. 55(2): 559-571.PDF
M.E. Bartlett and C.D. Specht. Evidence for the involvement of GLOBOSA-like gene duplications and expression divergence in the evolution of floral morphology in the Zingiberales. New Phytologist, 187: 521-541. PDF
C.D. Specht and M.E. Bartlett. 2009. Flower evolution: the origin and subsequent diversification of the angiosperm flower. Annual Review of Ecology Evolution and Systematics 40:217-243. PDF
Kirchoff, B.K., L.P. Lagomarsino, W.H. Newman, M.E. Bartlett & C.D. Specht. 2009. Early floral development in Heliconia latispatha and comparative evolution across Zingiberales. American Journal of Botany 96(3):1-15. PDF
Renner, T., J. Bragg, H.E. Driscoll, J. Cho, A. Jackson & C.D. Specht. 2009. Viral Induced Gene Silencing as a tool for investigating floral developmental genetics in the Zingiberales. Molecular Plant 3:1-11. PDF
Ling-Jing Chen, Zhao-Yan Diao, C.D. Specht, and Z. Renee Sung. 2009. Molecular Evolution of VEF-Domain-Containing PcG Genes in Plants. Molecular Plant 2:738-754. doi:10.1093/mp/ssp032
Nguyen, N, H.E. Driscoll, and C.D. Specht. 2008. A molecular phylogeny of the wild onions (Allium; Alliaceae) with a focus on the western North American center of diversity. Molecular Phylogenetics and Evolution 47: 1157-1172 PDF
Bartlett, M.E., B.K. Kirchoff, and C.D. Specht. 2008. Epi-illuminescence microscopy coupled to in situ hybridization and its utility in the study of evolution and development in non-model species. Development, Genes and Evolution 218(5): 273-279. PDF
Kress, W. J., M. Newman, A. Poulsen, and C. D. Specht. 2007. An analysis of generic circumscriptions in tribe Alpinieae (Alpinioideae: Zingiberaceae). The Gardens' Bulletin Singapore 59: 113-128.
Sass, C., D. Little, D.W. Stevenson and C.D. Specht. 2007. DNA-Barcoding in the Cycadales: Testing the potential of proposed barcoding markers for species identification of Cycads. PloS-ONE. 11: e1154. PDF
Funk, Vicki and C.D. Specht. 2007. Meta-trees: grafting for a global perspective. Proceedings of the Biological Society of Washington. 120(2): 233-241. PDF
Davis, J.I., G. Petersen, O. Seberg, D.W. Stevenson, C.R. Hardy, M.P. Simmons, F.A. Michelangeli, D.H. Goldman, L.M. Campbell, C.D. Specht, and J.I. Cohen. 2006. Are mitochondrial genes useful for the analysis of monocot relationships? Taxon 55:857-870.
Sjölander, K. and Specht, C.D. "Functional prediction through phylogenetic inference and structural classification of proteins." 2007. In R. Apweiler [ed.], The Encyclopedia of Genetics, Genomics, Proteomics, and Bioinformatics. J. Wiley & Sons, Ltd., West Sussex, UK.
Specht, C.D. "Gondwanan Vicariance or Dispersal in the Tropics? The biogeographic history of the tropical monocot family Costaceae (Zingiberales)." 2006. In J. T. Columbus, E. A. Friar, C. W. Hamilton, J. M. Porter, L. M. Prince, and M. G. Simpson, [eds.], Monocots: comparative biology and evolution. Rancho Santa Ana Botanic Garden, Claremont, California. PDF 277 kb
Kress, W.J. and Specht, C.D. "The evolutionary and biogeographic origin and diversification of the tropical monocot order Zingiberales." 2006. In J. T. Columbus, E. A. Friar, C. W. Hamilton, J. M. Porter, L. M. Prince, and M. G. Simpson, [eds.], Monocots: comparative biology and evolution. Rancho Santa Ana Botanic Garden, Claremont, California. PDF 277 kb
Petersen, G., O. Seberg, J.I. Davis, D.H. Goldman, D.W. Stevenson, L.M. Campbell, F.A. Michelangeli, C.D. Specht, M.W. Chase, M.F. Fay, J.C. Pires, J.V. Freudenstein, C. R. Hardy and M.P. Simmons. 2006. "Mitochondrial DNA and Monocot Phylogeny." In J. T. Columbus, E. A. Friar, C. W. Hamilton, J. M. Porter, L. M. Prince, and M. G. Simpson, [eds.], Monocots: comparative biology and evolution. Rancho Santa Ana Botanic Garden, Claremont, California. PDF 380 kb
Specht, C.D. and Stevenson, D.W. 2006 "A revised taxonomy for Costaceae (Zingiberales)." Taxon 51(1): 153-163. PDF 277 kb
Specht, C.D. 2006. "Systematics and Evolution of the tropical monocot family Costaceae (Zingiberales): a multiple dataset approach." Systematic Botany 31(1): 89-106. PDF 2332 kb
Specht, C.D. 2005. "Phylogenetics, Floral Evolution, and Rapid Radiation in the Tropical Monocot Family Costaceae (Zingiberales)." Pp. 29-60 in A.K. Sharma and A. Sharma, eds. Plant Genome: Biodiversity and Evolution. Science Publishers, Inc. Enfield, NH.
Kress, W. J. and C. D. Specht. 2005. "Between Cancer and Capricorn: phylogeny, evolution, and ecology of the tropical Zingiberales." In I. Friis and H. Balslev, eds. Proceedings of a symposium on plant diversity and complexity patterns - local, regional and global dimensions. Biologiske Skrifter, The Royal Danish Academy of Sciences and Letters, Copenhagen.
Davis, J.I., D.W. Stevenson, G. Petersen, O. Seberg, L.M. Campbell, J.V. Freudenstein, D.H. Goldman, C.R. Hardy, F.A. Michelangeli, M.P. Simmons, C.D. Specht, F. Vergara-Silva, and M.A. Gandolfo. 2004. "A phylogeny of the monocots, as inferred from rbcL and atpA sequence variation, and a comparison of methods for calculating jackknife and bootstrap values." Systematic Botany 29(3): 467-510. PDF 871 kb
Specht, C.D., Kress, W.J., Stevenson, D.W., and DeSalle, R. 2001. "A Molecular Phylogeny of Costaceae (Zingiberales)." Molecular Phylogenetics and Evolution 21(3):333-345. PDF 311 kb
Stevenson, D.W., Davis, J.D., Freudenstein, J.V., Hardy, C.R., Simmons, M.P., and Specht, C.D. 2000. "A Phylogenetic analysis of the Monocotyledons based on Morphological and Molecular character sets, with comments on the placement of Acoris and Hydetellaceae." Monocots: Systematics and Evolution. Eds K.L. Wilson and D.A. Morrison. CSIRO:Melbourne.
Lim, J., Heliarutta, Y., Specht, C.D., Jung, J., Sims, L., Bruce, W.B., Diehn, S., and Benfey, P.N. 2000. "Molecular Analysis of the SCARECROW Gene in Maize Reveals a Common Basis for Radial Patterning in Diverse Meristems." The Plant Cell 12:1307-1318. PDF 445 kb