Rosemary Gillespie

Professor, Director Essig Museum of Entomology
Ph.D.  Ecological modeling and behavior of spiders    University of Tennessee, Knoxville, 1986
B.Sc  Edinburgh University, 1980

201 Wellman Hall MC 3112
Berkeley, California 94720
gillespie@berkeley.edu
office: 510-642-3445   lab: 510-642-3445   fax:  510-642-7428

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My research focuses on the, evolution, biogeography, systematics and conservation biology of arthropods, with particular emphasis on spiders on oceanic islands. The primary goal of my research is elucidation of the factors responsible for the generation and loss of biodiversity. Because evolution occurs at a microcosmal level, isolated islands provide an extraordinary opportunity for examining these factors.

a) Adaptive Radiation of Spiders in the Hawaiian Islands. I am looking at extensive radiations of spiders in the Hawaiian Islands, in particular those in the genera Tetragnatha (Tetragnathidae) and Ariamnes (Theridiidae). In common with most Hawaiian spiders, representatives of these radiations remain largely unknown and undescribed. Over the last few years I have described a number of new species; many more remain to be described. These species radiations encompass a huge spectrum of colors, shapes, sizes, ecological affinities, and behaviors. Within the Tetragnatha radiation, many species are web-building, with structural modifications of the abdomen that allow concealment in specific microhabitats, while other groups have abandoned the characteristic web-building behavior of the genus. I am generating phylogenetic patterns of relationship for different clades of Hawaiian Tetragnatha and Ariamnes, and establishing relationships to mainland congeners, employing morphological and various molecular approaches. Using this information, I can test the role of morphological, ecological and behavioral attributes in dictating patterns of speciation. Results to date indicate that habitat associations play a key role in determining the level at which differentiation can occur within a lineage of spiders. Moreover, similar forms (“ecomorphs”) evolve repeatedly, resulting in the independent evolution of similar spider communities on each island.

In addition to the Hawaiian Islands, I am examining similar questions in the remote Pacific islands of French Polynesia, Fiji, and Micronesia, to assess the generalities underlying patterns of species diversity and diversification. This information is also used to predict the evolutionary future of a species/ lineage.

b) Evolution of color diversity and color polymorphism in Happy face spiders. The Hawaiian happy face spider Theridion grallator exhibits a spectacular array of color morphs, which can be plain either 'yellow' or 'patterned' (red, black or white patches differing in form and extent, on the yellow background). In collaboration with Dr. Geoffrey Oxford (University of York, England) we have shown that in Maui populations color is controlled by simple Mendelian alleles, with 'yellow' morphs recessive to all patterned morphs. There is no evidence of associations of any morphs with a particular sex on Maui. On the island of Hawaii populations exhibit a similar array of morphs to those on Maui. However, unlike Maui, 4 of the most common morphs show sex limitation. We have also found that selection plays a role in maintaining the polymorphism. We are currently investigating the mechanisms whereby the genetic differences between populations might have arisen and the role of selection in reinstating diversity subsequent to colonization of an island.

We have recently found a small spider, Theridion californicum from the west coast of California, which is remarkably similar to the happy face spider, with a similar set of color patterns, even held at similar frequencies. We are currently examining the genetic parallels between the color polymorphism of this spider and that of the happy face spider.

c) Conservation of native arthropods. I have been examining the impact of alien species in restricting the range of native species on isolated islands. Arthropods on a number of oceanic islands evolved in the absence of social Hymenoptera. Evidence to date suggests that ants are more devastating than any other ecological impact in causing the demise of lowland arthropods in Hawaii.

Garb, J.E., and R.G. Gillespie. 2009. Diversity despite dispersal: Colonization history and phylogeography of Hawaiian crab spiders inferred from multilocus genetic data . Molecular Ecology. 18: 1746-1764. Emerson, B.C. and R.G. Gillespie. 2008. Phylogenetic analysis of community assembly and structure over space and time. Trends in Ecology & Evolution 23(11): 619-630.

Gillespie, R.G., E.M. Claridge, and S. Goodacre. 2008. Biogeography of French Polynesia: Diversification within and between a series of hotspot archipelagoes. Phil. Trans. Royal Society London 363: 3335-3346. Krushelnycky, P.D. and R.G. Gillespie 2008. Compositional and functional stability of arthropod communities in the face of ant invasions. Ecological Applications. 18(6): 1547-1562.

Garb, J.E. and Gillespie R.G. 2006. Island hopping across the central Pacific: mitochondrial DNA detects sequential colonization of the Austral Islands by crab spiders (Araneae: Thomisidae). J. Biogeog 33(2): 201-220.

Benjamin, SP, D. Dimitrov, R.G. Gillespie, and G. Hormiga. 2008. Family ties: Molecular phylogeny of crab spiders (Araneae: Thomisidae). Cladistics 24: 708-722. Spagna, J., and R.G. Gillespie. 2008. More loci, fewer shifts: improving understanding of evolution of the spinning apparatus in non-orb-weaving spiders. Molecular Phylogenetics and Evolution 46: 347-368.

Gillespie, R.G., E.M. Claridge, and G.K. Roderick. 2008. Biodiversity dynamics in isolated island communities: Interaction between natural and human-mediated processes. Molecular Ecology 17: 45-57. Mitchell, B.M., and R.G. Gillespie. 2007. Graduate students take to the field in K-12 education. Public Library of Science (PLoS) Biology 5(6): 1200-1201.

Arnedo, M.A., I. Agnarsson, and R.G. Gillespie. 2007. Molecular Insights into the phylogenetic structure of the spider genus Theridion (Araneae, Theridiidae) and the origin of the Hawaiian Theridion-like fauna. Zoologica Scripta 36: 337-352.

Gillespie, R.G., and B.C. Emerson. 2007. Adaptation under a microscope. Nature 446: 386-387.

Gillespie R.G., and M.A. Rivera. 2007. Free-Living Spiders of the Genus Ariamnes (Araneae, Theridiidae) in Hawaii. Journal of Arachnology 35: 11-37.

Gillespie R.G. 2005. The ecology and evolution of Hawaiian spider communities. American Scientist.93:122-131.

Arnedo, M.A., and R.G. Gillespie. 2006. Species diversification patterns in the Polynesian jumping spider genus Havaika Proszynski 2001 (Araneae, Salticidae). Molecular Phylogenetics and Evolution 41: 472-495.

Pons, J. and Gillespie R.G. 2004. Evolution of satellite DNAs in a radiation of endemic Hawaiian spiders: Does concerted evolution of highly repetitive sequences reflect evolutionary history? Journal of Molecular Evolution 59 (5): 632-641.

Blackledge T. A. and Gillespie R.G. 2004. Convergent evolution of behavior in an adaptive radiation of Hawaiian web-building spiders. Proc. Natl Acad. Sci. USA 101 (46): 16228-16233

Garb, J.E., González, A., and Gillespie R.G. 2004. The black widow spider genus Latrodectus (Araneae: Theridiidae): phylogeny, biogeography and invasion history. Molecular Phylogenetics and Evolution 31(3): 1127-1142

Gillespie R.G. 2004. Community assembly through adaptive radiation in Hawaiian spiders. Science 303 (5656): 356-359

Vandergast, A.G., Gillespie R.G., and Roderick, G.K. 2004. Influences of volcanic activity on the population genetic structure of Hawaiian Tetragnatha. Molecular Ecology 13: 1729-1743.

Arnedo, M.A., Coddington, J.A., Agnarsson, I, and Gillespie R.G. 2004. From a Comb to a Tree: Phylogenetic Relationships of the Comb-footed Spiders (Araneae, Theridiidae) Inferred from Nuclear and Mitochondrial Genes. Molecular Phylogenetics and Evolution 31: 225-245.