Sharon Y. Strauss

Sharon Strauss

Position Title
Distinguished Professor Emerita

  • Evolution and Ecology
4326 Storer Hall

Profile Introduction

I study how evolutionary history shapes the traits and ecology of species.My goals are to use ecological and evolutionary processes to understand mechanisms that allow species to coexist in complex and diverse assemblages in nature, and to also understand how evolutionary processes of adaptation and speciation influence species' niches. I am also interested in using evolutionary processes to manage biodiversity, and the linkages between these principles and disease and resource management. I use a variety of tools including field experiments in nature, greenhouse experiments, literature surveys and phylogenetic methods to answer these questions.

Research Interests

Evolutionary Ecology of Plants and their Interactions with other Species

I am interested in how species evolve as a consequence of community membership (their complex interactions with co-occurring species). I study plant communities mostly, but also work with insect herbivores and pollinators of plants. Most recently, I have been focusing on the role of evolutionary history in community assembly of plants, and in explaining plant-herbivore ecology and evolution. I am also interested also in how invasive species evolve post-invasion in new habitats and the impacts of invasives on the ecology and evolution of co-occurring native species. I am also Principal Investigator on the Responding to Rapid Environmental Change IGERT see below, a graduate training program that fosters collaboration and multidisciplinary solutions to environmental problems. A more detailed discussion of the varied projects going on in my lab can be found at my website.

Using historical and contemporary approaches to reconstruct pathways to ecological specialization.

 Ecological specialists comprise a large portion of global biodiversity. In other words, not all species are equally good at living under the same conditions.  In this project, undertaken with colleague N. Ivalu Cacho (UNAM), I am working to understand the evolution of soil specialization in, and the evolutionary relationships among, members of the Streptanthoid complex, a diverse group of mustards, many endemic to the California Floristic Province. We have generated an evolutionary tree (phylogenetic hypothesis) for the group ( Cacho et al 2013, Molecular Evolution and Phylogenetics) and are using this hypothesis to understand trade-offs associated with soil specialization, specifically serpentine endemism. We use current ecological competition experiments in field soils, field and trait surveys and the phylogeny to understand the selective pressures and trade-offs, including both biotic and abiotic forces, leading to edaphic specialization (Cacho and Strauss 2014 PNAS). Our field sites span  Southern CA to Oregon, from deserts to high mountains, coastal areas and inland.

Streptanthus and allies are called ‘jewelflowers’ and I  think they are super cool and beautiful. This beauty helps keep me going when I am struggling in their preferred habitat of hot, south-facing very loose, steep and rocky slopes.

How well does the evolutionary relatedness between two species predict their ecological similarity?

 With Jean Burns and Brian Anacker, I am studying plant community assembly at the UC Bodega Marine Reserve. We use experimental approaches, planting individuals into the niches of more and less closely related species, to understand coexistence among species. By placing them in other species' niches, we can ask species how well they like it in their destination site. That's the nice thing about plants-- we can force them to grow in another species' niche.  Maybe not as cute as a meerkat, but oh-so-much more tractable to ask cool ecological and evolutionary questions

We are measuring many traits and environmental attributes across our site to understand the major contributors to coexistence in this diverse community. We also examine the role of soil microbes in mediating coexistence between different plant species.

Application of evolution to biodiversity, disease and resource management

I have a long-standing interest in how to apply our understanding of evolutionary processes to problems in biodiversity maintenance and resource management. I also appreciate the many cross-disciplinary commonalities between evolutionary challenges of insecticide resistance in crops pests and drug-resistance in human disease pathogens. Moreover, evolution and refuge theory can aid us in all of these areas, such as reducing the prevalence of Bt resistance in insects, reducing the ability of cancer cells to adapt to drug therapies, and reducing the impact of selective harvest on wild traits of fish stocks.

Grad Group Affiliations

  • Ecology
  • Population Biology

Specialties / Focus

  • Community Ecology
  • Evolutionary Ecology and Life History Strategies
  • Population Interactions


  • Biolgy BIS 2B Introduction to Biology: Principles of Ecology and Evolution
  • BIS 002B Introduction to Biology: Principles of Ecology and Evolution
  • EVE 181 Ecology and Evolution of Animal-Plant Interactions


  • Strauss Lab
    • See website

Field Sites

  • Northern California coastal prairie at Bodega Bay, Central Valley of California
  • serpentine outcrops and other habitats of plants in the clade Streptanthus

Honors and Awards

  • 2002-2003 UC Davis Chancellor's Fellow
  • 2009 Mercer Award from Ecological Society of America
  • 2009 Elected Fellow, California Academy of Sciences
  • 2015 Elected Fellow American Association of Arts and Sciences
  • 2015 Senior Fellow, Ecological Society of America
  • 2013 Per Brinck Award for Synthetic Ecological Contributions, Oikos Society, Sweden

    Professional Societies

    • American Society of Naturalists
    • Ecological Society of America
    • Botanical Society of America
    • Society for the Study of Evolution
    • American Association of Arts and Sciences


    • 1978 BA Biology Harvard University
    • 1984 MS Ecology University of Minnesota
    • 1988 PhD Biological Sciences Florida State University


    Select Recent publications(see others on my Google Scholar page).

    Phylogenetic conservatism in plant-soil feedback and its implications for plant abundance. Brian L. Anacker1,*, John N. Klironomos2, Hafiz Maherali3, Kurt O. Reinhart4 and Sharon Y. Strauss1 Article first published online: 17 OCT 2014 DOI: 10.1111/ele.12378 © 2014 John Wiley & Sons Ltd/CNRS Issue


    Occupation of bare habitats, an evolutionary precursor to soil specialization in plants. N. Ivalú Cacho1 and Sharon Y. Strauss. Science 17 October 2014: Vol. 346 no. 6207. DOI: 10.1126/science.1245993 REVIEW

    Mutualist-mediated effects on species' range limits across large geographic scales. Michelle E. Afkhami*, Patrick J. McIntyre and Sharon Y. Strauss. Article first published online: 22 JUL 2014. DOI: 10.1111/ele.12332 © 2014 John Wiley & Sons Ltd/CNRS Issue


    Ecological and evolutionary responses in complex communities: implications for invasions and eco-evolutionary feedbacks. SY Strauss Oikos 123 (3), 257-266. 7, 2014