Ecology and Evolution | Biological Sciences

Ecology and Evolution

Faculty research interests in the area of ecology and evolution include conservation and evolutionary genetics (Aguilar Lab), theoretical population biology (Desharnais Lab), bryophyte ecology and evolution (Fisher Lab), evolutionary ecology of marine invertebrates (Krug Lab), Plant Physiology, Anatomy, Ecology, and Evoution (Scoffoni Lab), evolutionary history of marine organisms (Torres Lab), avian ecology and applied conservation (Wood Lab), and Plant Community Ecology and Ecophysiology (Wright Lab). An asterisk following a name in a publication citation indicates a student coauthor.

Conservation and Evolutionary Genetics

Prickly sculpin     Contact:  Andres Aguilar, Ph.D.
Office:  ASCL 215, ext: 3-2078
Laboratory:  ASCB 346
E-mail:  aaguil67@calstatela.edu
Web:  http://andresaguilar.weebly.com
Prickly sculpin (Cottus asper) are a native freshwater fish species in California. Genetic evidence suggests isolation of coastal and inland forms may represent the early stages of speciation.

Research Summary
Our current work studies evolutionary, ecological and conservation based questions. We employ a variety of molecular genetic, genomic, computational and field approaches. Major areas of study include the evolution and conservation of California's native freshwater ichthyofauna and evolutionary genomic studies of diverse group of marine fishes (rockfish). We also work on endangered vernal pool crustaceans, amphibians, and sea birds.

Representative Publications
Baumsteiger, J.D., Kinziger, A.P., and Aguilar, A. 2012. Life history and biogeographic diversification of an endemic western North American freshwater fish clade using a comparative species tree approach. Molecular Phylogenetics and Evolution, in press.
Heras, J., Koop, B., and Aguilar, A. 2011. A transcriptomic scan for positively selected genes in two closely related marine fishes: Sebastes caurinus and S. rastrelliger. Marine Genomics 4: 93-98.
Aguilar, A. 2011. Weak phylogeographic structure in the endemic western North American fairy shrimp Branchinecta lynchi (Eng, Belk and Erickson 1990). Aquatic Sciences 73: 15-20.
Aguilar, A., and Jones, W.J. 2009. Nuclear and mitochondrial diversification in two native California minnows: insights into taxonomic identity and regional phylogeography. Molecular Phylogenetics and Evolution 51: 373-381.
Aguilar, A., Roemer, G., Debenham, S., Binns, M., Garcelon, D., and Wayne, R.K. 2004. High MHC diversity maintained in an otherwise genetically monomorphic mammal. Proceedings of the National Academy of Sciences USA 101: 3490-3494.

 

Theoretical Population Biology

 

Adult flour beetle     Contact:  Robert A. Desharnais, Ph.D.
Office:  ASCB 323D, ext: 3-2056
Laboratory:  ASCB 342, ext: 3-2033
E-mail:  rdeshar@calstatela.edu
Web:  http://caldera.calstatela.edu/rdeshar
Ventral view of an adult flour beetle, Tribolium castaneum. Populations of these insects are used as a laboratory model for testing ecological theory.

Research Summary
Our research interests are in the area of theoretical and experimental population biology. We use of insect populations to test predictions of nonlinear population models, including phenomena such as chaos, the effects of stochasticity, and metapopulation synchrony. We are also working with the Robles laboratory on models of the dynamics of marine mussel beds. Our methods involve mathematical models, computer simulations, and laboratory population experiments with flour beetles.

Representative Publications
Donahue, M.J., Desharnais, R.A., Robles, C.D., Arriola, P.* 2011. Mussel bed boundaries as dynamic equilibria: thresholds, phase shifts, and alternative states. The American Naturalist 178: 612-625.
Robles, C.D., Desharnais, R.A., Garza, C., Donahue, M.J., and Martinez, C.A.* 2009. Complex equilibria in the maintenance of boundaries: experiments with mussel beds. Ecology 90: 985-995.
Desharnais, R.A., Costantino, R.F., Cushing, J.M., Henson, S.M., Dennis, B, and King, A.A. 2006. Experimental support for the scaling rule of demographic stochasticity. Ecology Letters 9: 537-547.
Reuman, D.C., Desharnais, R.A., Costantino, R.F., Ahmad, O.S., and Cohen, J.E. 2006. Power spectra reveal the influence of stochasticity on nonlinear population dynamics. Proceedings of the National Academy of Sciences USA 103: 18860-18865.
Desharnais, R.A., Dennis, B., Cushing, J.M., Henson, S.M., and Costantino, R.F. 2001. Chaos and population control of insect outbreaks. Ecology Letters 4: 229-235.

 

Bryophyte Ecology and Evolution

 

Tropical moss with asexual propagules     Contact:  Kirsten Fisher, Ph.D.
Office:  ASCL 393, ext: 3-2089
Laboratory:  ASCL 351, ext: 3-2085
E-mail:  kfisher2@calstatela.edu
Web:  http://instructional1.calstatela.edu/kfisher2
Tropical moss, Calymperes tenerum, with asexual propagules.

Research Summary
Our research interests include plant molecular systematics, phylogeography, and the use of phylogenetic trees for exploring evolutionary questions in general. In particular, we apply molecular phylogenetic methods to understanding cryptic diversity in mosses. We are investigating the potential link between physiological specialization and cryptic diversification in this group of plants, focusing on the desiccation tolerant model moss Syntrichia ruralis.

Representative Publications
Fisher, K. 2011. Sex on the edge: reproductive patterns across the geographic range of the Syrrhopodon involutus (Calymperaceae) complex. The Bryologist 114: 674-685.
Fisher, K. 2008. Bayesian reconstruction of ancestral gene expression in the LEA families reveals propagule-derived desiccation tolerance in resurrection plants. American Journal of Botany 95: 506-515.
Fisher, K., Wall, D.P., Yip, K.L., and Mishler, B.D. 2007. Phylogeny of the Calymperaceae, with a rank-free systematic treatment. The Bryologist 110: 43-73.
Fisher, K. 2006. Rank-free monography: a practical example from the moss clade Leucophanella. Systematic Botany 31: 13-30.
La Farge, C., Mishler, B.D., Wheeler, J.A., Wall, D.P., Johannes, K., Schaffer, S., and Shaw, A.J. 2000. Phylogenetic relationships of the Haplolepideous mosses. The Bryologist 103: 257-276.

 

Evolutionary Ecology of Marine Invertebrates

 

Caribbean sea slug     Contact:  Patrick Krug, Ph.D.
Office:  ASCL 314, ext: 3-2076
Laboratory:  ASCL 325, ext: 3-2098
E-mail:  pkrug@calstatela.edu
Web:  http://instructional1.calstatela.edu/pkrug/lab
The Caribbean sea slug Elysia crispata stores chloroplasts from the algae it eats and can go months between meals, living off of photosynthesis performed by the hijacked plastids.

Research Summary
Our lab studies the evolution of dispersal and habitat colonization by planktonic larvae of marine animals, aiming to identify factors that limit gene flow, set range limits, and promote local adaptation. We use herbivorous sea slugs as a model system to investigate the evolution of alternative larval strategies, and to study ecological speciation in the sea. Field studies focus on a dynamic range boundary in San Francisco Bay, examining physical and biological forces that allow two species to cyclically displace each other every year. We are also building a molecular phylogeny, or family tree, of algae-eating sea slugs to study the evolution of traits such as larval type and host use.

Representative Publications
Krug, P.J., Asif, J.H.*, Baeza, I.*, Morley, M., Blom, W. and Gosliner, T. 2012. Molecular identification of two species of the carnivorous sea slug Philine, invaders of the U.S. west coast. Biological Invasions, in press.
Asif, J.H.*, and Krug, P.J. 2012. Lineage distribution and barriers to gene flow among populations of a globally invasive marine mollusc. Biological Invasions 14: 1431-1444.
Krug, P.J., Gordon, D.*, and M. Romero*. 2012. Seasonal polyphenism in larval type: Rearing environment influences the development mode expressed by adults in the sea slug Alderia willowi. Integrative & Comparative Biology 52: 161-172.
Vendetti, J.E., Trowbridge, C.D., and P. J. Krug. 2012. Poecilogony and population genetic structure in Elysia pusilla (Heterobranchia: Sacoglossa), and reproductive data for five sacoglossans that express dimorphisms in larval development. Integrative & Comparative Biology 52: 138-150.
Smolensky, N.*, Romero, M.*, and Krug, P.J. 2009. Evidence for costs of mating and self-fertilization in a simultaneous hermaphrodite with hypodermic insemination, the opisthobranch Alderia willowi. Biological Bulletin 216: 188-199.

 

Plant Physiology, Anatomy, Ecology, and Evolution

 

Venation     Contact Christine Scoffoni, Ph.D.
Office:  ASCB 323A, ext: 3-2070
Laboratory:  ASCB 341
E-mail:  cscoffo@calstatela.edu
Web:  https://christinescoffoni.wordpress.com/

The puzzling fact about leaf veins is that even though they serve similar functions across all plant species (water and sugar transport, leaf mechanical support), they have evolved widely different architectures and anatomies, even within closely related species such as these three Proteaceae. We are investigating the function behind this surprising diversity.

Research Summary

Our research uses experimental and comparative approaches in plant physiology, ecology and evolution to answer fundamental questions regarding the function of plant diversity with an emphasis on plant’s adaptation to environmental stresses such as drought. More specifically, why do species exhibit such diversity in leaf size, shape and venation architecture? What are the physiological and anatomical traits that drive species’ resistance to drought? We work on a broad range of questions relating to plant hydraulics and leaf venation architecture, species adaptation to drought, and to the evolution of plant traits.

Representative Publications

Scoffoni C, Sack L. 2017. Darwin Review. The causes and consequences of leaf hydraulic decline with dehydration. Journal of Experimental Botany, in press (doi.org/10.1093/jxb/erx252).

John GP, Scoffoni C, Buckley TN, Villar R, Poorter H, Sack L. 2017. The anatomical and compositional basis of leaf mass per area. Ecology Letters, 20: 412-425.

Scoffoni C, Albuquerque C, Brodersen C, Townes S*, John GP, Bartlett MK, Buckley TN, McElrone AJ, Sack L. 2017. Outside-xylem vulnerability, not xylem embolism, controls leaf hydraulic decline during dehydration. Plant Physiology, 173: 1197-1210.

Scoffoni C, Chatelet D, Pasquet-Kok J*, Rawls M*, Donoghue M, Edwards E, Sack L. 2016. Hydraulic basis for the evolution of photosynthetic productivity. Nature Plants. 16072.

Scoffoni C, Kunkle J, Pasquet-Kok J*, Vuong C*, Patel AJ*, Montgomery R, Givnish TJ, Sack L. 2015. Light induced plasticity in leaf hydraulics, anatomy and gas exchange in ecologically diverse Hawaiian lobeliads. New Phytologist. 207: 43-58.

Scoffoni C, Vuong C*, Diep S*, Cochard H, Sack L. 2014. Leaf shrinkage with dehydration: coordination with hydraulic vulnerability and drought tolerance. Plant Physiology.164: 1772-1788.

Sack L, Scoffoni C. 2013. Tansley Review. Leaf venation: structure, function, development, evolution, ecology and applications in past, present and future. New Phytologist. 198: 983-1000.

Sack L, Scoffoni C, McKown AD, Frole K, Rawls M*, Havran JC, Tran H, Tran S. 2012. Developmentally-based scaling laws for leaf venation architecture explain global patterns. Nature communications. 3: 837.

Bartlett MK, Scoffoni C, Sack L. 2012. The determinants of leaf turgor loss point and prediction of drought tolerance of species and biomes: a global meta-analysis. Ecology Letters. 15: 393-405.

Scoffoni C, Rawls M*, McKown A, Cochard H, Sack L. 2011. Decline of leaf hydraulic conductance with dehydration: relationship to leaf size and venation architecture. Plant Physiology 156: 832-843.

 

Taxonomy & Evolution of Marine Ostracodes

 

Ostracod crustacean that lives off of the Pacific Coast     Contact:  Elizabeth Torres, Ph.D.
Office:  ASCL 313, ext: 3-2179
Laboratory:  ASCL 311, ext: 3-5856
E-mail:  etorre11@calstatela.edu
Web:  http://www.calstatela.edu/faculty/etorre11/etorre11.htm
Vargula tsujii is a cypridinid ostracod crustacean that lives off of the Pacific Coast of North America. It secretes a bright blue luminescence produced in the light organ (yellow vertical bar just below the compound eye).

Research Summary
We use molecular methods and classic taxonomic approaches to understand phylogeny, diversity, and speciation in Caribbean cypridinid ostracode crustaceans. We are especially interested in the evolution of bioluminescence in cypridinids. Our genetic data have revealed several new species in the Caribbean, which we are in the process of describing. Students in our lab have also worked on other taxa, such as butterflies, Channel Island foxes, fox squirrels, marine snails, and bioluminescent fish.

Representative Publications
Torres, E., and Morin, J.G. 2007. Vargula annecohenae, a new species of bioluminescent ostracode (Myodocopida: Cypridinidae) from Belize. Journal of Crustacean Biology 27: 649-659.
Torres, E., and Gonzalez, V.L. 2007. Molecular phylogeny of cypridinid ostracodes and the evolution of bioluminescence. In Proceedings of the 14th International Symposium on Bioluminescence and Chemiluminescence: Chemistry, Biology, and Applications. A.A. Szalay, P.J. Hill, L.J. Kricka, and P.E. Stanley (eds). New Jersey: World Scientific Publishing Company, pgs. 269-272.
Torres, E., and Cohen. A.C. 2005. Vargula morini, a new species of bioluminescent ostracode (Myodocopida: Cypridinidae) from Belize and an associated copepod (Copepoda:Siphonostomatoida:Nicothoidae). Journal of Crustacean Biology 2: 11-24.
Torres, E., Lees, D.C., Vane-Wright, R.I., Kremen, C., Leonard, J.A., and Wayne, R.K. 2001. Testing monophyly in a large radiation of Madagascan butterflies (Lepidoptera: Satyrinae: Mycalesidina) based on mitochondrial DNA data. Molecular Phylogenetics and Evolution 20: 460-473.

 

Avian Ecology and Conservation

 

w     Contact:  Eric Wood, Ph.D.
Office:  ASCL 312, ext: 3-2055
Laboratory:  ASCB 310
E-mail:  EricMWood@calstatela.edu
Web:  http://www.ericmwood.org
The Yellow-rumped Warbler (Setophaga coronata) is a migratory songbird that uses lowland areas throughout the Los Angeles region during the wintering period and migration. Yellow-rumped Warblers are an excellent study species for understanding the impacts of urbanization on biodiversity as well as the effects of climate change and extreme weather on phenological relationships between birds and their seasonal food resources.

Research Summary
We work to understand the impacts of global and environmental change on biodiversity with a focus on applied conservation. Our research is centered on terrestrial ecosystems and avian communities, and we use field and citizen science data, spatial analyses, and quantitative approaches to explore processes and patterns for pressing conservation issues. We strive to work with a wide range of partners; including government agencies, NGOs, and community members to link scientific outcomes with conservation applications.

Representative Publications
Wood, E. M. and A. M. Pidgeon. Extreme variations in spring temperature affect ecosystem regulating services provided by birds during migration. in press Ecosphere
Wood, E. M. and J. L. Kellerman, Editors. Studies in Avian Biology (no. 47). 2015. ‘Phenological synchrony and bird migration: changing climate and seasonal resources in North America’
Wood, E. M., A. M. Pidgeon, V. C. Radeloff, P. D. Culbert, N. S. Keuler, and C. H. Flather. 2015. Long-term avian community response to housing development at the boundary of U.S. protected areas: effect size increases with time. Journal of Applied Ecology 52:1227-1236
Wood, E. M., A. M. Pidgeon, V. C. Radeloff, D. Helmers, P. D. Culbert, N. S. Keuler, and C. H. Flather. 2014. Housing development erodes avian community structure in U.S protected areas. Ecological Applications 24:1445-1462
Wood, E. M., A. M. Pidgeon, D. J. Mladenoff, and F. Liu. 2012. Birds see the trees inside the forest: the potential impacts of changes in forest composition on songbirds during spring migration. Forest Ecology and Management 280:176-186.

Plant Community Ecology, Ecophysiology

 

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    Contact:  Alexandra Wright Ph.D.
Office:  ASCL 315, ext: 3-2065
Laboratory:  ASCL 327
E-mailawrigh20@calstatela.edu
Web:  https://sashajwright.wordpress.com
 

Research Summary
Our lab focuses on the relationship between biodiversity and ecosystem function.  Higher biodiversity plant communities tend to be more productive and more stable than lower diversity plant communities. This can mean increased yield in an agricultural context, and increased stability in the face of a rapidly changing climate.  We explore the mechanisms that help explain positive biodiversity effects: why/how do plants sometimes benefit their neighbors? We also explore how these effects change at different spatial scales and in different types of environments (urban, arid, heavily managed agricultural environments, etc).

Representative Publications

Wright, A., de Kroon, H., Visser, E.J.W., Buchmann, T., Ebeling, A., Eisenhauer, N., Fischer, C., Hildebrandt, A., Ravenek, J., Roscher, C., Weigelt, A., Weisser, W., Voesenek, L.A.C.J., Mommer, L.  2017.  Plants are less negatively affected by flooding when growing in species-rich plant communities. New Phytologist 213(2): 645-656.

Wright, A., Gaxiola, A., Wardle, D., Callaway, R. 2017. The overlooked role of facilitation in biodiversity experiments. Trends in Ecology and Evolution 32(5): 383-390.

Wright, A., Ebeling, A., de Kroon, H., Roscher, C., Weigelt, A., Buchmann, N., Buchmann, T., Fischer, C., Hacker, N., Hildebrandt, A., Oelmann, Y., Steinauer, K., Weisser, W., and Eisenhauer, N.  2015. Flooding disturbances increase resource availability and productivity but reduce stability in diverse plant communities.  Nature Communications 6: 6092.

Wright, A., Schnitzer, S.A., and Reich, P.B. 2015. Daily environmental conditions determine the competition-facilitation balance for plant water status. Journal of Ecology 103(3): 648-656.

Wright, A., Schnitzer, S.A., and Reich, P.B. 2014. Living close to your neighbors – the importance of both facilitation and competition in plant communities. Ecology 95: 2213-2223.

 

Note: ADM = Administration Building, ASCL = Wallis Annenberg Integrated Science Complex-Wing A (La Kretz Hall), ASCB = Wallis Annenberg Integrated Science Complex-Wing B. When calling from off-campus, the area code and prefix for all telephone extensions is (323) 34X-XXXX.