A strong component of any study of biodiversity is understanding the overall distribution of species and what this can tell us about the history of the environment they live in - how has the landscape been fragmented, how has dispersal played a role in maintaining continuity among regions, and why are some areas more diverse than others? I use phylogenetic and population genetic/phylogeographic methods to reconstruct the evolutionary history of species and populations (Wares 2001a,b,c; Wares and Cunningham 2001, Wares 2002); comparisons of such patterns with those found in other taxa can lead to profound insights about how communities are assembled and how climate change affects the distribution and abundance of species.


Very good local observations about how species interact may change when considered at larger scales. A good case in point is how the interactions and density of species changes dramatically from north of Cape Blanco, Oregon (very high density of species and larval recruits) to the low-density populations south of Cape Blanco. Working with Rob Toonen (Hawai’i Institute of Marine Biology) and Rick Grosberg (UC Davis) we have tried to collect genealogical data that will give us some insight into how this demographic pattern may be reflected in the distribution of genetic diversity among regional populations. I am working on a comparable genetic analysis of barnacle populations on the Chilean coast, in collaboration with Sergio Navarrete.


Particularly in the shallow intertidal zone, we are still learning how subtle oceanographic forces may play a strong role in the divergence of species. My work at Point Conception (Wares et al. 2001) indicates that strong advection may have long-term consequences for the formation and maintenance of species boundaries, and several projects on the biogeography and habitat use of intertidal barnacles (Wares and Cunningham 2005, Wares and Castañeda 2005) is illustrating how species may differentiate due to ecological differences despite being in close geographic proximity to closely related taxa. Barnacles (and many other taxa) in the tropics and temperate zones may spatially assort by wave exposure; the mechanism for this ecologically-driven pattern of speciation is still not clear.


Wares, J.P, S.D. Gaines and C.W. Cunningham. 2001. A comparative study of asymmetric migration events across a marine biogeographic boundary. Evolution 55 (2):295-306.

Wares, J.P. 2001. Intraspecific variation and geographic isolation in Idotea balthica (Isopoda: Valvifera). Journal of Crustacean Biology 21(4): 1007-1013.

Wares, J. P. and A. E. Casta–eda. 2005. Geographic range in Chthamalus along the west coast of North America. Journal of the Marine Biological Association of the U.K. 85: 327-331.

Wares, J. P. 2002. Community genetics in the northwestern Atlantic intertidal. Molecular Ecology 11: 1131-1144.

Wares, J.P. and T. F. Turner. 2003. Phylogeography and diversification in aquatic mollusks. In C. F. Lydeard and D. R. Lindberg, eds. Molecular Systematics and Phylogeography of Mollusks. Smithsonian Press. Pp 229-269.

Sotka, E. E., J. P. Wares, and M. E. Hay. 2003. Geographic and genetic variation in feeding preferences for chemically-defended seaweeds. Evolution 57 (10): 2262-2276.3

Sanford, E., M. S. Roth, G. C. Johns, J. P. Wares, and G. N. Somero. 2003. Local selection and latitudinal variation in a marine predator-prey interaction. Science 300: 1135-1137.