Staff Homepage

Dr. G. Stone

Location: Ashworth Annexe

Telephone:0131 650 7194, lab - 0131 650 5516
Email:Graham.Stone@ed.ac.uk

Web-Site:

C.V.

Research groupings

Population Genetics
Evolution, Animal Ecology and Behaviour

Teaching

I teach in several courses introducing the diversity and evolution of animal body plans, animal-plant interactions, and marine biology. I have contributed to tropical ecology courses in Kenya, run by the Tropical Biology Association, and co-authored a university level textbook on environmental physiology (The Environmental Physiology of Animals, by Pat Willmer, Graham Stone and Ian Johnston, Blackwells Science 1^st Edn. 2000, 2^nd Edn. 2005), now in its second edition.

Research interests

I am a community ecologist with a strong focus on insect-plant interactions, combining molecular and field approaches to study of natural communities. I try to understand the role of evolutionary history in community composition, and in explaining why some species interact while others don’t. I work with two ‘model systems’ – gallwasps & their parasitoid natural enemies; & savannah plants, their pollinators & ant guards.

Community evolution and phylogeography
We use within-species genetic diversity to identify the origins and patterns of range expansion of species, using oak gallwasps and their chalcid parasitoids as a model system. Our main research question is whether the species making up these communities comprise sets of species with a long history of interaction, or recent assemblages from multiple origins. Which of these is true has major implications for the impacts of global climate change, extinction, and biological invasion.

Character evolution
We use multispecies phylogenies to test hypotheses about the evolution of animal reproductive strategies (Stone et al. 2008), host plant associations (Cook et al. 2002), and defence against natural enemies (Stone & Schonrogge 2003).

Sequence-based analyses of the spread of microbial Symbionts through natural communities.
We use pcr-based approaches to examine the dispersal pattern through insect communities of bacterial symbionts including Cardinium, Flavobacteria, Spiroplasma and Wolbachia through communities (Rokas et al. 2002). Our current focus is the extent to which these symbionts are transmitted across trophic levels.

Field-based analyses of community structure.
We use interaction webs to understand the structure of parasitoid-host and pollinator-plant interactions, and to examine the impacts of invading species on the structure of native communities.
We are examining the impact on native gallwasps and parasitoid communities of multiple recent invasions of northwestern Europe by oak gallwasps. We combine traditional identification techniques with DNA sequence ‘barcodes’, which allows us to link the eggs, larvae and adults of a single species and to separate biologically distinct but morphologically extremely similar species.
We use pollination webs to reveal the extent to which shared pollinators either facilitate pollination for multiple plant species, or mediate competition between them. We are using population genetic analysis of pollen flow in two acacia species (Senegalia brevispica and S. mellifera) to reveal how far pollinating insects travel, and hence the spatial scale over which competition/facilitation for pollination operates. This work is based at Mpala Research Centre, Kenya and builds on previous work on community pollination ecology in Tanzania (Stone et al. 1998), Mexico (Raine et al. 2002, 2007) and Australia.
We have also examined the potentially negative interactions between ant guards and pollinators. Though both are mutualists of a range of plants, the guards could potentially interfere with pollinator activity. We have shown that two ant-acacia mutualisms in America and Africa have evolved the same solution to the problem: short-lived floral ant repellents that keep ants away while the pollinators do their work (Willmer & Stone 1997; Raine et al. 2002).

Environmental physiology: I use analyses of the thermal requirements of flight in bees and other insects to reveal the links between individual physiology and animal behaviour, particularly foraging and courtship.

Collaborations:
I have much valued long-standing collaborations with:

• Prof. James Cook (Reading University, phylogenetic analyses of character trait and community evolution)
• Prof. Jane Memmott (Bristol University, plant-pollinator webs)
• Dr. Nigel Raine (Queen Mary College, University of London, pollination ecology)
• Prof. Andrew Schnabel (University of Indiana, acacia population structure).
• Dr Karsten Schönrogge (CEH Wallingford, gallwasp community ecology)
• Prof. Pat Willmer (St. Andrews University; pollination ecology)

The gallwasp community work involves collaborations with many highly respected taxonomists and field biologists, including Drs. Yoshihisa Abe (Kyushu University), Dick Askew (Emeritus), György Csóka (Hungarian State Department of Forest Protection), George Melika (Plant Protection & Soil Conservation Directorate of County Vas), Jose-Luis Nieves-Aldrey (Museo Nacional de Ciencias Naturales, Madrid), and Juli Pujade-Villar (Barcelona University).

Representative publications

Stone GN, Atkinson RJ, Rokas A, Nieves-Aldrey J-L, Melika G, Ács Z, Csoka G, Hayward A, Bailey R, Buckee C, McVean GAT (2008). Evidence for widespread cryptic sexual generations in apparently asexual Andricus gallwasps. Molecular Ecology 17: 652-665.

Stone GN, van der Ham RWJM, & Brewer JG (2008). Fossil oak galls preserve ancient
multitrophic interactions. Proc. R. Soc. Lond. Ser. B. 275: 2213-2219.

Challis RJ, Mutun S, Nieves-Aldrey J-L, Preuss S, Rokas A, Aebi A, Sadeghi E, Tavakoli M, & Stone GN, (2007) Longitudinal range expansion and cryptic eastern species in the western Palaearctic oak gallwasp Andricus coriarius. Molecular Ecology 16: 2103-2114.

Stone GN, Challis RJ, Atkinson RJ, Csoka G, Hayward A, Mutun S, Preuss S, Rokas A, Sadeghi E, Schonrogge, K (2007) The phylogeographic clade trade: tracing the impact of human-mediated dispersal on the colonisation of northern Europe by the oak gallwasp Andricus kollari. Molecular Ecology 16: 2768-2781.

Hayward A and Stone GN (2006) Comparative phylogeography across two trophic levels: the oak gall wasp Andricus kollari and its chalcid parasitoid Megastigmus stigmatizans. Molecular Ecology, 15: 479-489.

Willmer PG & Stone GN (2004). Factors structuring the daily activity patterns of Bees. Advances in the Study of Animal Behaviour 34: 347-466.

Stone GN & Sconrogge K (2003). The adaptive significance of insect gall morphology. Trends in Ecology and Evolution 18: 512-522.

Cook JM, Rokas A, Pagel M & Stone GN (2002). Evolutionary shifts between host oak sections and host plant organs in Andricus gallwasps. Evolution 56: 1821-1830.

Raine NE, Willmer PG & Stone GN. (2002). Spatial structuring and floral repellence prevent ant-pollinator conflict in a Mexican ant-acacia Ecology 83: 3086–3096.

Rokas A, Atkinson RJ, Nieves-Aldrey J-L, West, SA & Stone, GN (2002). The incidence and diversity of Wolbachia in gallwasps (Hymenoptera; Cynipidae) on oak. Molecular Ecology 11: 1815-1829.

Stone GN, Schonrogge K, Atkinson RJ, Bellido D & Pujade-Villar J (2002). The population biology of oak gallwasps (Hymenoptera: Cynipidae). Annual Review of Entomology 47: 633-668.

Stone GN, Willmer PG & Rowe JA (1998). Partitioning of pollinators during flowering in an African Acacia community. Ecology 79: 2808-2827.

Willmer PG & Stone G (1997). Ant deterrence in Acacia flowers: how aggressive ant-guards assist seed-set. Nature  388: 165-167.