About

The page provides a list of lab members and visitors associated with The John N Thompson Lab, which focuses on coevolution and the organization of biodiversity. The lab's research encompasses several major problems related to coevolution, including the spatial scale of coevolutionary mosaics, specialization, adaptation, speciation, and the genomic structure of coevolution. It also investigates the evolution of complex traits and correlations in coevolving interactions, as well as links to other evolutionary and ecological processes. The lab explores coevolution in large webs of interacting species, emphasizing the geographic mosaic of coevolutionary patterns. The research aims to understand the organization and dynamics of biodiversity through these various lenses.

Research topics

• Biology
• Ecology
• Evolutionary biology
• Genetics
• Botany
• Zoology

Selected publications

• Direct Effects of Polyploidization on Floral Scent

  Journal of Chemical Ecology · 2025-09-10 · 1 citations

  articleOpen access

  Polyploidy is an important driver of the evolution and diversification of flowering plants. Several studies have shown that established polyploids differ from diploids in floral morphological traits and that polyploidization directly affects these traits. However, for floral scent, which is key to many plant-pollinator interactions, only a few studies have quantified differences between established cytotypes, and the direct effects of polyploidization on floral scent are not yet known. We compared the floral scent of established polyploids and diploids from a natural mixed-ploidy population of the plant Lithophragma bolanderi (Saxifragaceae), a species pollinated by two highly specialized moth pollinators of the genus Greya (Prodoxidae). We also compared the floral scent of neopolyploids synthetically generated from diploids with the floral scent of the diploid progenitors to quantify the direct effects of polyploidization on floral scent. Established tetraploids had a higher floral scent emission rate, produced more scent compounds, and emitted a relative scent composition that differed from diploids. Neotetraploids differed in the same direction from diploids as established tetraploids from diploids, but to a lesser extent. Together, our results provide novel insights into the ways in which polyploidization reshapes floral scent, thereby potentially altering interactions between plants and pollinators.

  PublisherOA PDFDOI

• Repeated polyploidization shapes divergence in floral morphology in <i>Lithophragma bolanderi</i> (Saxifragaceae)

  Proceedings of the National Academy of Sciences · 2025-08-13 · 2 citations

  articleOpen access

  Polyploidization is an important driver of evolution and diversification in flowering plants. Here, we assess how repeated polyploidization may have shaped diversification of floral morphology in Lithophragma bolanderi (Saxifragaceae). This species comprises multiple cytotypes and varies geographically in its interactions with specialized pollinating moths in the genus Greya (Prodoxidae). Past studies have shown that coevolution with these moths has favored particular suites of floral characters but does not fully explain local and regional floral diversification. We combined phenotypic and genomic data from more than 1,800 individuals from 40 L. bolanderi populations spread across its entire range. Flow-cytometric analyses revealed a geographic mosaic of populations comprising one to four of three dominant (diploid, tetraploid, hexaploid) and three rare (triploid, pentaploid, octoploid) cytotypes. Whole-genome resequencing of a subset of populations suggested that polyploids arose from multiple autopolyploidization events, rather than a single event and/or through hybridization, albeit with some signals consistent with low levels of introgression from the congener Lithophragma glabrum . Quantification of flower traits from plants grown in a common garden showed that cytotype explained more than 15% of the variation in floral morphology, with polyploids showing more variability than diploids. Experimental induction of neopolyploids directly induced phenotypic changes but also indicated that local selection may have favored subsequent convergence in floral morphology among cytotypes in natural populations. Collectively, this comprehensive and integrative approach provides insights into how variability generating processes, such as polyploidization integrates with selection from species interactions to shape local floral diversification.

  PublisherDOI

• Components of local adaptation and divergence in pollination efficacy in a coevolving species interaction

  Ecology · 2023-03-28 · 9 citations

  articleOpen access

  Selection leading to adaptation to interactions may generate rapid evolutionary feedbacks and drive diversification of species interactions. The challenge is to understand how the many traits of interacting species combine to shape local adaptation in ways directly or indirectly resulting in diversification. We used the well-studied interactions between Lithophragma plants (Saxifragaceae) and Greya moths (Prodoxidae) to evaluate how plants and moths together contributed to local divergence in pollination efficacy. Specifically, we studied L. bolanderi and its two specialized Greya moth pollinators in two contrasting environments in the Sierra Nevada in California. Both moths pollinate L. bolanderi during nectaring, one of them-G. politella-also while ovipositing through the floral corolla into the ovary. First, field surveys of floral visitors and the presence of G. politella eggs and larvae in developing capsules showed that one population was visited only by G. politella and few other pollinators, whereas the other was visited by both Greya species and other pollinators. Second, L. bolanderi in these two natural populations differed in several floral traits putatively important for pollination efficacy. Third, laboratory experiments with greenhouse-grown plants and field-collected moths showed that L. bolanderi was more efficiently pollinated by local compared to nonlocal nectaring moths of both species. Pollination efficacy of ovipositing G. politella was also higher for local moths for the L. bolanderi population, which relies more heavily on this species in nature. Finally, time-lapse photography in the laboratory showed that G. politella from different populations differed in oviposition behavior, suggesting the potential for local adaptation also among Greya populations. Collectively, our results are a rare example of components of local adaptation contributing to divergence in pollination efficacy in a coevolving interaction and, thus, provide insights into how geographic mosaics of coevolution may lead to coevolutionary diversification in species interactions.

  PublisherOA PDFDOI

• Indirect effects shape species fitness in coevolved mutualistic networks

  Nature · 2023 · 33 citations

  • Biology
  • Ecology
  • Evolutionary biology
  PublisherOA PDFDOI

• The ripple effects of clines from coevolutionary hotspots to coldspots

  Molecular Ecology · 2023-06-09 · 2 citations

  letterOpen access1st authorCorresponding

  Coevolution has the potential to alter not only the ecological interactions of coevolving partners, but also their interactions with yet other species. The effects of coevolution may ripple throughout networks of interacting species, cascading across trophic levels, swamping competitors, or facilitating survival or reproduction of yet other species linked only indirectly to the coevolving partners. These ripple effects of coevolution may differ among communities, amplifying how the coevolutionary process produces geographic mosaics of traits and outcomes in interactions among species. In a From the Cover article in this issue of Molecular Ecology, Hague et al. (2022) provide a clear example, using the well-studied interactions between Pacific newts (Taricha spp.) and their common garter snake (Thamnophis sirtalis) predators in western North America. Pacific newts harbour tetrodotoxin (TTX), which is highly toxic to vertebrate predators. In coevolutionary hotspots, extreme escalation of toxicity in the newts and resistance to toxicity in the snakes have resulted in snake populations that retain high levels of TTX. In two geographic regions, snakes in these hotspot populations have evolved bright, aposematic colours that may act as warning signals to their own vertebrate predators. The warning signals and toxin-resistance alleles in the snake populations decrease clinally away from the coevolutionary hotpots, shaped by a geographically variable mix of selection imposed by the snakes' prey and by their own predators.

  PublisherOA PDFDOI

• The Adaptive Radiation of Coevolving Prodoxid Moths and Their Host Plants:

  Princeton University Press eBooks · 2021-07-13 · 2 citations

  book-chapter1st authorCorresponding
  PublisherDOI

• In remembrance of Victor Rico Gray (1951‐2021): An astonishing tropical ecologist

  Biotropica · 2021-06-26

  articleOpen access

  Abstract In this remembrance, we have brought together some of Victor Rico‐Gray’s friends and collaborators to recall his many contributions to tropical ecology and his influence on so many young scientists. Victor’s research ranged from Mexican ethnobotany to the evolutionary ecology of complex interactions between ants and plants. His research was highly collaborative, forming strong bonds among those who shared his interests in how the web of life is organized. He inspired students through his mentoring in tropical ecology, mainly his lectures at the Instituto de Ecología AC (INECOL), and later at the Universidad Veracruzana (UV), his courses organized by the Organization for Tropical Studies (OTS), and his talks at meetings, including the Association of Tropical Biology and Conservation (ATBC). Victor’s story is not over. It will continue to be traced through countless scientists who were inspired by Victor’s life and work.

  PublisherOA PDFDOI

• Coevolution and Macroevolution

  Springer eBooks · 2021 · 3 citations

  1st authorCorresponding
  • Biology
  • Evolutionary biology
  • Ecology
  PublisherDOI

• Generalized olfactory detection of floral volatiles in the highly specialized Greya-Lithophragma nursery pollination system

  Arthropod-Plant Interactions · 2021 · 7 citations

  Senior authorCorresponding
  • Biology
  • Botany
  • Zoology

  Abstract Volatiles are of key importance for host-plant recognition in insects. In the pollination system of Lithophragma flowers and Greya moths, moths are highly specialized on Lithophragma , in which they oviposit and thereby pollinate the flowers. Floral volatiles in Lithophragma are highly variable between species and populations, and moths prefer to oviposit into Lithophragma flowers from populations of the local host species. Here we used gas chromatography coupled with electroantennographic detection (GC-EAD) to test whether Greya moths detect specific key volatiles or respond broadly to many volatiles of Lithophragma flowers. We also addressed whether olfactory detection in Greya moths varies across populations, consistent with a co-evolutionary scenario. We analyzed flower volatile samples from three different species and five populations of Lithophragma occurring across a 1400 km range in the Western USA, and their sympatric female Greya politella moths. We showed that Greya politella detect a broad range of Lithophragma volatiles, with a total of 23 compounds being EAD active. We chemically identified 15 of these, including the chiral 6, 10, 14-trimethylpentadecan-2-one (hexahydrofarnesyl acetone), which was not previously detected in Lithophragma . All investigated Lithophragma species produced the (6 R , 10 R )-enantiomer of this compound. We showed that Greya moths detected not only volatiles of their local Lithophragma plants, but also those from allopatric populations/species that they not encounter in local populations. In conclusion, the generalized detection of volatiles and a lack of co-divergence between volatiles and olfactory detection may be of selective advantage for moths in tracking hosts with rapidly evolving, chemically diverse floral volatiles.

  PublisherOA PDFDOI

• Genetic correlations and ecological networks shape coevolving mutualisms

  Ecology Letters · 2020-09-24 · 23 citations

  letter

  Ecological interactions shape the evolution of multiple species traits in populations. These traits are often linked to each other through genetic correlations, affecting how each trait evolves through selection imposed by interacting partners. Here, we integrate quantitative genetics, coevolutionary theory and network science to explore how trait correlations affect the coevolution of mutualistic species not only in pairs of species but also in species-rich networks across space. We show that genetic correlations may determine the pace of coevolutionary change, affect species abundances and fuel divergence among populations of the same species. However, this trait divergence promoted by genetic correlations is partially buffered by the nested structure of species-rich mutualisms. Our study, therefore, highlights how coevolution and its ecological consequences may result from conflicting processes at different levels of organisation, ranging from genes to communities.

  PublisherDOI

Recent grants

• Evolution of Specificity in Insect/Plant Interactions

  NSF · $356k · 1991–1994

• The geographic mosaic of coevolving plant-insect lineages

  NSF · $641k · 2009–2015

• Evolution of Specificity in Insect/Plant Interactions: The Relationship of Oviposition Preference and Larval Performance

  NSF · $241k · 1987–1991

• Geographic Mosaics in Diversifying Plant-Insect Interactions

  NSF · $592k · 2004–2009

• OPUS: The Structure and Dynamics of Selection on Evolving Interactions

  NSF · $109k · 2011–2015

Frequent coauthors

• Ingrid M. Parker

  University of California, Santa Cruz

  30 shared

• Joel E. Cohen

  30 shared

• Robert J. Cabin

  25 shared

• Pamela O’Neil

  University of New Orleans

  25 shared

• Paulo R. Guimarães

  Universidade de São Paulo

  25 shared

• Jane Molofsky

  25 shared

• Fred W. Allendorf

  University of Montana

  25 shared

• Syndallas Baughman

  University of Vermont

  25 shared

Education

• PhD

  University of Illinois System

  1977

Awards & honors

• Darwin-Wallace Medal for Major Contributions to Evolutionary…
• Per Brinck Oikos Award for Contributions to the Science of E…
• Fellow of the American Association for the Advancement of Sc…
• Fellow of the California Academy of Sciences
• Fellow of the American Academy of Arts and Letters