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.