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Justen B. Whittall

Associate Professor



B.S. 1996 Santa Clara University, Biology, cum laude
M.S. 1999 Oregon State University, Plant Systematics
Ph.D. 2005 University of California Santa Barbara, Plant Evolution
Postdoctoral Fellowship, University of California Davis, Comparative Phylogenetics


My lab is focused on describing macroevolutionary patterns and microevolutionary processes underlying angiosperm diversification. We use modern phylogenetic comparative methods, experimental evolutionary ecology, and quantitative genetics to test evolutionary hypotheses. Some of the guiding questions are:

  * Is evolution predictable? Does it proceed in repeated directions
    across the tree of life?
  * What is the molecular basis for convergent evolution?
  * How does pleiotropy constrain the genes involved in adaptation
    and speciation?

Currently, I am looking for directional trends in flower color evolution, focusing on the most widespread secondary plant pigments, anthocyanins. Anthocyanins are essential for pollinator attraction, yet are constrained by their roles in plant defense, UV protection and other metabolic functions. The six core genes in the linear pathway are conserved across angiosperms allowing for broad comparative studies on the degree of molecular convergence and constraint during plant evolution. I am now using quantitative PCR and full genome microarrays to discern the molecular basis for flower color polymorphisms. When coupled with quantitative field experiments to discern the selective agents, my lab hopes to reveal predictable patterns underlying plant diversification. In answering these questions, I strive to develop creative avenues for undergraduate participation in original research projects.

  • Bio 22 Introduction to Evolution & Ecology
  • Bio 134 California Plant Diversity L&L
  • Bio 173 Evolution L&L
  • Bio 179 Bioinformatics L&L

For a more complete listing of publications, please view CV.

SCU coauthors in bold followed by graduation year

• Casimiro-Soriguer, Inés, José Carlos Del Valle, M. Luisa Buide, Eduardo Narbona, Justen B. Whittall. Transcriptome and biochemical analysis of a flower color polymorphism in Silene littorea (Caryophyllaceae). Frontiers in Plant Biology (in review).

• Del Valle, José Carlos, M. Luisa Buide, Inés Casimiro-Soriguer, Justen B. Whittall, Eduardo Narbona. 2015. On flavonoid accumulation in different plant organs: Unraveling the variation among individuals and populations in the shore campion (Silene littorea). Frontiers in Plant Biology 6:939.

Butler, Timothy (’10), Dick, Cynthia A. (’08), Matthew L. Carlson, Justen B. Whittall. 2014. Transcriptome analysis of a petal anthocyanin polymorphism in the arctic mustard, Parrya nudicaulis. PLoS ONE 9(7): e101338.

Dick, Cynthia (’08), Julie Herman (’14), Ryan E. O’Dell, Adriana LopezVillalobos, Chris Eckert, Justen B. Whittall. 2013. Cryptic genetic subdivision in the San Benito evening primrose (Camissonia benitensis). Conservation Genetics 15:165-175.

• Fulkerson, Justin R., Justen B. Whittall, Matthew L. Carlson. 2012. Reproductive ecology and severe pollen limitation in the polychromic tundra plant, Parrya nudicaulis (Brassicaceae). PLoS ONE 7(3): e32790. • Whittall, Justen B. and Scott A. Hodges. 2012. Aquilegia. The Jepson Manual 2. UC Press, CA.

• Grossenbacher, Dena and Justen B. Whittall. 2011. Increased floral divergence in sympatric monkeyflowers. Evolution 65: 2712-2718.

Dick, Cynthia A. (’08), Jason Buenrostro (’09), Timothy Butler (’10), Daniel J. Kliebenstein, Matthew L. Carlson, Justen B. Whittall. 2011. Arctic mustard flower color polymorphism controlled by petal-specific downregulation at the threshold of the anthocyanin biosynthetic pathway. PLoS ONE 6(4): e18230.

• Anacker, Brian1 , Justen B. Whittall1 , Emma Goldberg and Susan Harrison. 2011. Origins and consequences of serpentine endemism in the California flora. Evolution 65: 365-376 ( 1 both authors contributed equally)

Whittall, Justen B., John Syring, Matthew Parks, Jason Buenrostro (’09), Cindy Dick (‘08), Aaron Liston, and Richard Cronn. 2010. Finding a (Pine) Needle in a haystack: Chloroplast genome sequence divergence in rare and widespread pines. Molecular Ecology 19: 100-114.