Josh on Table Mountain		 Joshua McDill

B.S.: Botany, San Francisco State University

M.A.: Ecology and Systematic Biology, S.F.S.U.

  • Thesis: Comparative Leaf and Stem Anatomy in Linanthus and Related Genera (Polemoniaceae)

Ph.D.: In Progress

  • Dissertation research: The Phylogeny, Biogeography, and Evolution of Linum (flax, Linaceae)

Contact: josh.m at mail.utexas.edu
The Linaceae is a relatively small but widespread and diverse angiosperm lineage, with 13 currently recognized genera  (~300 species) distributed throughout the temperate and tropical regions of the world.  The largest genus is Linum, with 200 species including the cultivated flax, Linum usitatissimum, which has been grown for thousands of years as an important source of fibers and seed oils.  The other genera range from tropical trees and climbers (eg, Hugonia) to tiny temperate annuals (eg, species of Hesperolinon, a serpentine endemic of California).

My dissertation research centers on the evolutionary history of the lineage of Linaceae that has diversified around the Mediterranean, in Southern Africa, and in the Americas.  This lineage includes Linum sections Linopsis, Syllinum, and Catharticum, as well as the North American genera Hesperolinon and Sclerolinon, the South American Cliococca, and European Radiola.  Preliminary results show that this lineage is sister to the blue-flowered linums, which are essentialy confined to Eurasia.  I am estimating the phylogeny of the 130 species in the yellow-flowered lineage using DNA sequence data from multiple chloroplast and nuclear markers.  The phylogeny will be used to test biogeographic hypotheses that potentially explain the current amphi-atlantic and amphi-tropical distribution of this lineage as the product of historical events such as continental drift,  land-bridge migration, or long-distance dispersal.  In conjunction with breeding system studies, the phylogeny will also be used to test the hypothesis that the evolution of self compatibility in yellow-flowered linums facilitated their dispersal among continents. 

I am also collaborating with Miriam Repplinger and Dr. Joachim Kadereit (Johannes Gutenberg-Universitaet, Mainz, Germany) on the general phylogeny of the Linaceae and a revised generic taxonomy for the family.

 

View my  C.V.

Read my NSF Dissertation Improvement Grant proposal.

Pictures from the South America collecting trip (2004).

Pictures from western Texas (2005).

Pictures from South Africa (2005-2006).