Ellen L. Simms

Ellen L. Simms

Professor Emeritus

Email: esimms@berkeley.edu
Phone: 510-847-5770

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Research Description

We are fascinated by evolution in natural populations. We study how contemporary evolution affects ecological interactions between plants and other organisms, such as herbivores, pathogens, and mutualists. We seek to understand which mechanisms influence the evolution of traits important to biotic interactions. We also apply ecological and evolutionary theory to improve plant conservation, control of invasive species, and ecosystem services.

Current graduate students and postdocs are studying

  • how metapopulation structure influences resilience and risk of metapopulation extinction
  • how cooperation traits in legume hosts and rhizobium symbionts evolve in response to natural selection by nitrogen and carbon dioxide enrichment, and how these evolutionary changes are influencing ecosystem services
  • population genetic structure of N-fixing Bradyrhizobium of native and invasive legumes
  • the structure of terrestrial cyanobacterial populations

Past graduate students have studied 

  • natural selection on mutualistic traits in legumes and nitrogen-fixing bacteria
  • evolution in a community of figs and fig-wasps
  • natural selection on ecological and reproductive traits in selfing and outcrossing populations of annual lupines
  • the role of heavy metal sequestration in herbivore defense of serpentine plants
  • population genetics of clonally reproducing orchids, inbreeding depression in Lobelia cardinalis
  • symbiotic specificity of orchid-mycorrhizal interactions
  • the evolution of seed dispersal in Cakile edentula

Selected Publications

Porter, S. S. and E. L. Simms. 2014.  Selection for cheating across disparate environments in the legume-rhizobium mutualism. Ecology Letters 17(9):1121-1129.

Ehinger, M., T. J. Mohr, J. B. Starcevich, J. L. Sachs, S. S. Porter, E. L. Simms. 2014.  Specialization-generalization trade-off in a Bradyrhizobium symbiosis with wild legume hosts. BMC Ecology 14:8. doi:10.1186/1472-6785-14-8

Simms, E. L. and S. S. Porter. 2012.  Transcriptomic insights into mechanisms of symbiotic cooperation. Molecular Ecology 21(9):4665-4668.

Jandér, K. C. , E. A. Herre, and E. L. Simms. 2012.  Precision of host sanctions in the fig tree – fig wasp mutualism: consequences for uncooperative symbionts. Ecology Letters 15(2):1362 – 1369. DOI: 10.1111/j.1461-0248.2012.01857.x

Akçay, E. and E. L. Simms. 2011.  Negotiation, sanctions and context dependency in the legume-rhizobium mutualism. American Naturalist 178(1):1-14.

Sachs, J. L., M. O. Ehinger, and E. L. Simms. 2010.  Origins of cheating and loss of symbiosis in wild Bradyrhizobium. Journal of Evolutionary Biology 23(5):1075 – 1089.

Sachs, J. L., S. W. Kembel, A. H. Lau, and E. L. Simms. 2009.  In situ phylogenetic structure and diversity of wild Bradyrhizobium communities. Applied and Environmental Microbiology 75(14):4727 – 4735.

Franks, S. J., P. D. Pratt, F. A. Dray, E. L. Simms. 2008.  No evolution of increased competitive ability or decreased allocation to defense in an invasive plant since release from natural enemies. Biological Invasions 10(4):455 – 466.

Sachs, J. L., and E. L. Simms. 2008.  The origins of uncooperative rhizobia. Oikos 117(7):961-966.

Franks, S. J., P. D. Pratt, and E. L. Simms. 2008. Selection on herbivory resistance traits and competitive ability in an invasive plant. American Naturalist 171(5):678 – 691.

Palomino, M. T., P. G. Kennedy, E. L. Simms.  2007.  Nickel hyperaccumulation as an anti-herbivore trait: considering the role of tolerance to damage.  Plant and Soil 293:189-195.

Shefferson, R. P. and E. L. Simms.  2007.  Costs and benefits of fruiting to future reproduction in two dormancy-prone orchids.  Journal of Ecology 95:865-875.

Sachs, J. L. and E. L. Simms.  2006.  Instability of mutualisms:  Pathways to mutualism breakdown.  Trends in Ecology & Evolution 21(10):585-592.

Simms, E. L., D. L. Taylor, J. Povich, R. P. Shefferson, J. D. Sachs, Y. Tausczik, M. Urbina. 2005. An empirical test of partner choice mechanisms in a legume-rhizobium interactions. Proc. Roy. Soc. Lond. B, Proc. Royal Soc. Series B 273 (1582): 77-81.

2005.  Hausmann, J., T. E. Juenger, S. Sen, K. A. Stowe, T. E. Dawson, E. L. Simms.  Quantitative trait loci (QTL) affecting 13C and response to differential water availability in Arabidopsis thaliana.  Evolution 59(1):81-96. 

Juenger, T., S. Sen, K. Stowe, and E. L. Simms. 2005. Epistasis and gene-environment interaction for quantitative trait loci affecting flowering time inArabidopsis. Genetica, 123(1-2):87-105.

Shefferson, R.P., J. Proper, S.R. Beissinger, and E.L. Simms. 2003. Dormancy and life history trade-offs in a terrestrial slipper orchid: An analysis using mark-recapture statistics. Ecology 84(5):1199-1206.

Simms, E.L., and D.L. Taylor. 2002. Partner choice in nitrogen fixation mutualisms of legumes and rhizobia. Integ. & Comp. Biol. 42(2):369-380.

West, S.A., E.T. Kiers, E.L. Simms, and R.J. Denison. 2002. Nitrogen fixation and the stability of the legume-rhizobium mutualism. Proc. Royal Soc. London Series B 269:685-694.

Chase, J.M., M.A. Leibold, and E.L. Simms. 2001. Plant tolerance and resistance in food webs: Community-level predictions and evolutionary implications. Evol. Ecol. 14:289-314.

Bever, J.D. and E.L. Simms. 2000. Evolution of nitrogen fixation in spatially structured populations of Rhizobium. Heredity 85:366-372.