Species’ Range Limits

As academic biologists in today’s world, many of us are faced with the challenge of how to continue to do basic research when our study species are declining or are even threatened with extinction. This challenge will only broaden in scope as the global human population places increasing demands on the Earth’s resources and increasing stress on the Earth’s ecosystems in the 21stCentury. As such, evolutionary ecology, almost by necessity, is becoming a science that inherently deals with global change. Climate change, for example, is predicted to alter the geographic ranges of many, if not most, of the Earth’s species, resulting in range shifts, contractions or expansions. To understand and mitigate this pressing threat to global biodiversity, it is first essential to understand the mechanisms and processes that underlie species’ geographic range limits. We applying molecular genomic tools, as well as reciprocal transplant experiments to test hypotheses regarding species’ range limits in the endemic streamside salamander, limited primarily to the US state of Kentucky, while its congener, the small-mouthed salamander has a much broader geographic range. In contrast, we are also studying limits to the geographic range of the cane toad as it invades Australia.

  • Micheletti, S. and A Storfer. 2017. An approach for identifying cryptic barriers to gene flow that limit species’ geographic ranges. Molecular Ecology 26: 490-504.
  • Trumbo, D.R., B. Epstein, L. Schawazkopf, P.A. Hohenlohe, R. Alford and A. Storfer. 2016. Mixed population genomics support for the central marginal hypothesis across the invasive range of the cane toad (Rhinella marina) in Australia. MolecularEcology 25: 4161-4176.
  • Micheletti, S. and A. Storfer. 2015. A test of the central-marginal hypothesis using population genetics and ecological niche modelling in an endemic salamander (Ambystoma barbouri). Molecular Ecology 24: 967-979.
  • Trumbo, D., S.F. Spear, J. Baumsteiger and A. Storfer. 2013. Rangewide landscape genetics of an endemic Pacific Northwestern salamander. Molecular Ecology. 22: 1250-1266.
  • Eastman, J.M., J.N. Niedzwiecki, B.P. Nadler and A. Storfer. 2009.  Duration and consistency of historical selection are correlated with adaptive trait evolution in the streamside salamander, Ambystoma barbouri. Evolution 63: 2636–2647.