The following individuals were graduate students (G), postdoctoral associates (PD), long-term visiting scholars (V), or Technicians (T) in our lab since the mid 1990s. These are some of their representative research interests. Current lab members, collaborators, and visitors are listed on the Current Lab Members page

David Althoff (G)

How are different kinds of “traits” — molecular, morphological, behavioral — of interacting species organized across large geographic scales?

Specific example: Phylogeography and geographic structure of interacting insects and their parasitoids. Comparative geographic studies of molecular, morphological, and behavioral traits in interacting pairs of Greya moth and Agathis wasp species across the northern Rockies.

Currently on the faculty at Syracuse University


Paulette Bierzychudek (Chair of Biology at Lewis and Clark College, Portand, Oregon) (V)

Spent the 2002-2003 year in our laboratory on sabbatical leave from Lewis and Clark College in Portland, Oregon, where she is Chair of Biology. She devoted the year to working on major issues in conservation biology and on her long-term datasets on the dynamics of natural selection on plant populations.


Ryan Calsbeek (PD)

Large-scale comparative phylogeographic structure of animals and plants in California and comparative rates of molecular diversfication.

Specific example: Analysis of the major phylogeographic breaks found in plants, vertebrates, and insects along the Coast Ranges of California.

Currently on the faculty at Dartmouth College


Bradley Cunningham (G; T)

What is the geographic scale of local adaptation in phytophagous insects that are both herbivores and pollinators of their host plants?

Specific example: Analysis of ability of Greya moths to differentiate among populations of Lithophragma plants in the northern Rockies.

Currently with an environmental consulting firm in Nevada


Paulo Guimarães (PD)

How does coevolution shape large networks of interacting mutualistic species?

Specific example: How does coevolution shape the evolution of traits in large networks of pollinators and plants or frugivores and plants?

Currently on the faculty at the University of Sao Paulo


Niklas Janz (PD)

How does plant polyploidy affect host shifts in phytophagous insects and diversification of plant/insect interactions?

Specific example: Studies of how insect colonization of a novel plant genus is shaped by polyploidy within some of the plant populations.

Currently on the faculty at the University of Stockholm


Britt Koskella (PD)

Can coevolving species generate geographic mosaics of adaptation over very small spatial scales?

Can species rapidly coevolve simultaneously with more than one other species?

Specific examples: Field studies of adaptation of plant-associated bacteria and bacteriophages at different the levels of landscapes and individual trees (in collaboration with Angus Buckling’s laboratory); experimental evolution of bacteria and multiple phage types in laboratory microcosms

Currently on the faculty at University of California, Berkeley


Cristina Lorenzi (V)

Spent a leave from her research position at the University of Turin in our laboratory.

How do hosts and brood-parasitic species coevolve as a geographic mosaic?

Specific project: Evaluation of her long-term data on coevolution between Polistes wasps and closely related Polistes species that are brood parasites of Polistes wasp nests

Currently on the faculty at University of Paris


Kurt Merg (G)

How has repeated evolution of polyploidy within plants shaped the genetic structure of plant species and diversification in plant/pollinator interactions?

Specific example: Molecular and ecological analysis of how autopolyploids of different origin in Heuchera grossulariifolia have evolved different population structures and relationships with different pollinator taxa.

Currently at Washington Fish and Game, in charge of efforts to develop conservation efforts on private lands in eastern Washington


Scott Nuismer (G)

How is coevolution shaped by selection mosaics, coevolutionary hotspots, gene flow, and the genetic structure of interacting species?

Specific examples: Mathematical models of how coevolutionary hotspots and gene flow shape mutualistic and antagonistic interactions. Empirical studies of how the genetic structure of populations, including the evolution of polyploidy, affects attack by insect with different feeding strategies.

Currently on the faculty at tthe University of Idaho


Kari Segraves (G)

How do multiple origins of polyploidy affect diversification of plant traits and interactions with pollinators?

Specific example: Studies of the effects of polyploidy on the evolution of floral morphology and interactions with pollinator guilds within natural populations of Heuchera grossulariifolia.

Currently on the faculty at Syracuse University


Jason Hoeksema (PD)

What is the geographic scale at which coevolving species show evidence of local adaptation, and what is the structure of selection mosaics?

Specific example: Studies of selection mosaics between pines and mycorrhizal fungi over large geographic scales, spanning Alaska to Baja California.

Currently on the faculty at University of Mississippi


Catherine Fernandez (PD)

Are cryptic species embedded within widespread species?

How do interactions between species diversify across ecosytems?

Specific example: Studies of geographic differences in the ecological outcome of interactions between Greya moths and Lithophragma plants, and studies of molecular differentiation among populations of Greya and Grimmea species.

Currently at BD Biosciences


Mariana Cuautle Arenas (PD)

How to pollinator networks differ between sympatric plant species?

How do pollinator networks on a plant species vary geographically

Specific example: How do sympatric species of Lithophragma differ in their pollinator assemblages in different geographic regions

Currently at UDLA, Puebla, Mexico


Sarah Dwiggins (T)

What is the degree of prereproductive and postreproductive isolation among species within highly divergent floral morphologies within the genus Lithophragma.

She graduated with honors based on her NSF REU research in our laboratory, prior to becoming a technician in our lab.

Now working for the California organic farming certification program..


Anna-Liisa Laine (V)

Spent parts of two years in our lab as a long-term visiting scientist while on appointment at the University of Helsinki.

How do co-occurring congeneric parasitic/mutualistic species affect interactions with hosts?

Specific example: Effects of co-occurring Greya moths on pollination and fitness of Lithophragma plants near the geographic range limit of the interaction?

Currently on the faculty at the University of Helsinki


Katherine Rich (G)

What is the comparative pattern of phylogeographic differentiation in closely species that use the same hosts?

Specific example: Phylogeographic studies of how closely related Greya moths have genetically differentiated across far western North America


Samantha Forde (PD)

How do selection mosaics shape coevolving bacteria and phage in microcosms?

Specific example: Tests of the geographic mosaic theory of coevolution using E. coli and T3 phage in laboratory microcosm the create productivity gradients. The tests have included evaluations of the rate of coevolution and the dynamics of resistance polymorphisms and infectivity polymorphisms in geographic mosaic microcosms as compared with panmictic microcosms.

Currently a program director at The Gordon and Betty Moore Foundation and an adjunct faculty member in Ecology and Evolutionary Biology at UCSC.


Magne Friberg (PD)

How does biochemical signaling between species diversify as populations of the coevolving taxa undergo selection in different ecosystems?

Specific example: Geographic and phylogenetic divergence in the interactions between saxifragaceous plants and their specialized prodoxid moth pollinators. These studies included analyses of divergence in floral scent among populations and species of Lithophragma and the extent to which scent composition affects host plant preference in Greya moths. This work was, and continues to be, a collaboration between our laboratory and Robert A. Raguso’s lab at Cornell University in Ithaca, New York, with assistance from the Marine Analytical Lab at UCSC. See Friberg et al. 2012 Annals of Botany.

Currently an assistant professor at Uppsala University.


Hirokazu Toju (V)

How do do species-rich networks assemble?

Specific example: Network structure of mycorrhizal associations in species-rich forests in Japan and southeast Asia

Hirokazu is an assistant professor at Kyoto University, who was an extended visitor to our lab during 2011-2012 academic year to work on the problem of analysis of complex networks of coevolving species. We are collaborating on questions about the network structure of complex mutualisms.


Min Liu (V)

How do historical processes shape the phylogeographic structure of coevolving species?

Specific example: Coevolution of figs and fig wasps across China. Her doctoral research was on cryptic speciation in coevolving figs and fig wasps in China and discussing other research.

Min Liu spent part of the 2012-2013 academic year in our laboratory, when she was a finishing doctoral student at East China Normal University.

She is now at the South China Botanical Garden.

1970s to middle 1990s:

The following is a list of graduate students (G), postdoctoral associates (PD), long-term academic visitors (V), and technicians (T) from the late 1970s through about the middle 1990s at Washington State University. This list is incomplete and will be updated.

Douglas Biedenweg (G)

Susan Stone Bookman (G)

Richard Ellison (G)

Hal Hansel (T)

Amitabh Joshi (G)

David Mohr (T)

Olle Pellmyr (PD)

Jon K. Piper (G)

Paul Spruell (PD)

Mark Tiritilli (G)

Lisa Valburg (G)

Diane Wagner (PD)

Gimme Walters (V)

Wayne Wehling (T, G)

Undergraduates at UCSC:

The following individuals were undergraduate students in our lab at UCSC in recent years. Most have been part of the lab’s formal undergraduate internship program, and most have been funded in part through NSF’s Research Experience for Undergraduates Program.


Phil Hoos: A graduate of UCSC, recently completed field work in Nicaragua and is currently at Moss Landing Marine Labs. He graduated with honors based on his NSF REU research in our laboratory.

David Hembry: A graduate of Harvard University, followed by a fellowship at the Institute of Ecology in Kyoto, Japan, a doctoral dissection UC Berkeley, and a postdoctoral fellowship at Kyoto University. He is now a postdoctoral associate at UC Berkeley. He worked during summer for part of his undergraduate years and then for some months between completion of his undergraduate degree and his time in Japan.

Ben Wendel: A graduate of Haverford College, then the University of Washington. He worked in our laboratory one summer, helping with preparation of molecular samples.

Noelle German: A graduate of UCSC, now in nursing.

Sarah Dwiggins: A graduate of UCSC, now working for the California organic farming certification program.. She graduated with honors based on her NSF REU research in our laboratory, before taking a position first in a biotechnology firm and then in the California organic garden certification program.

Bridget Piculell: A graduate of UCSC, followed by work as a research technician for Walt Koenig, and then a degree program in scientific illustration. She is now in graduate school studying plant-mycorrhical interactions at the University of Mississippi. She graduated with honors based on her research in our laboratory.

Christopher Schwind: A graduate of UCSC, Chris graduated with honors based on his NSF REU research in our laboratory, and also undertook other research projects on plant-mycorrhizal interactions with Jason Hoeksema. Chris managed our lab for five years after his graduation and then returned as a graduate students.

Jessie Bunkley: A graduate of UCSC, Jessie is currently a graduate student at Boise State University

Lindsey Roark: A graduate of UCSC, Lindsey worked on how environmental conditions affect the expression of floral traits, especialy floral scents, in divergent populations of plants coevolving with pollinators. She completed an honors thesis in our lab. She is currently a graduate student at the University of Amsterdam.

Aliya Ingersoll: A graduate of UCSC, Aliya worked on genetic crosses between plants with contrasting floral traits.

Current undergraduates: see page on Current Lab Members