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Dwarfism and gigantism have evolved repeatedly on islands throughout the world.  We're studying the evolution of dwarfism in reptiles on the California Channel Islands by comparing them with their mainland counterparts from Los Angeles to San Mateo county, testing for physiological and molecular mechanisms involved in generating these remarkably small body sizes, as well as associated changes in life-history and behaviour. For more formation, visit



Tonia Schwartz (Auburn University)

David Miller (Penn State)

Melody Russel (Auburn University)

Recent Publication:

Sparkman A.M., Clark A.D., Brummett L.J., Chism K.R., Combrink L.C.,  Kabey, N.M., Schwartz T.S. (2018). Convergence in reduced body size, head size, and blood glucose in three island reptiles. Ecology and Evolution, 00:1–14.


Evolution of Dwarfism on the California Channel Islands

Organisms in urban environments may face numerous  challenges, including differences in habitat structure, light and noise pollution, resource availability, predators, mutualists, and/or competitors.  Both the western fence lizard (Sceloporus occidentalis) and the acorn woodpecker (Melenerpes formicivorus) have successfully colonized urban environments throughout the west. By comparing morphology, reproduction, behaviour, physiology and occupancy between more urban individuals and their more wild counterparts, we're interested in exploring how strategies for persisting in urban spaces differ across the urban gradient.

Recent Publication:

Sparkman A.M., Howe S., Hynes S., Hobbs B., Handal K. (2018). Parallel behavioral and morphological divergence in fence lizards on two college campuses. PLoS ONE, 13(2): e0191800.

Morphological, Behavioural, and Physiological Responses to Urbanization

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