
A male Anolis cristatellus dewlaps on a tree in Miami, Florida. Picture reproduced with permission from Kolbe et al. (2012).
Anoles are remarkably adaptable creatures. You can find anoles in hostile environments, such as the tops of mountains in the Dominican Republic, in near-desert environments, and in places with over-winter freezing. Anoles are also a model system for rapid evolution; in response to strong selective pressure, an equally strong evolutionary response occurs within a few generations. It is perhaps unsurprising, then, that anoles are also one of the most invasive reptiles in the World. Although they are endemic to the tropical and subtropical regions of the New World, today anoles can also be found in such remote places as Guam, Hawaii, Taiwan, and Hong Kong.
One of the major questions surrounding anole invasions is how the organisms will respond to the challenges of a new environment. When anoles invade new environments they inevitably encounter new thermal and hydric conditions – how do these anoles adapt to a different environment? Jason Kolbe has spent many years exploring the ecology and genetics of Anolis invasions, and has focused especially on invasions in Florida (1, 2, 3). The Puerto Rican trunk-ground, A. cristatellus, has been found in Key Biscayne and South Miami since the mid-1970s. Ambient temperature is important for A. cristatellus and other anoles have been documented to acclimate to low temperatures. In this study Jason Kolbe and colleagues addressed two questions: (1) To what extent does the thermal environment change from Puerto Rico to Florida? and (2) Is there a phenotypic response in tolerance to cold?