Physiological variation among invasive populations of the brown anole (Anolis sagrei).
Invasive species often encounter novel climatic conditions when they spread outside of their native ranges. Invading populations can respond to novel conditions by acclimation or adaptation of physiological capacities, which may facilitate their spread. We investigated differences in physiological traits among three populations of an invasive lizard, the brown anole (Anolis sagrei), along the latitudinal extent of its invasion in the southeastern United States. We predicted latitudinal clines for most traits based on models of adaptation to climate. Consistent with the latitudinal cline in temperature and moisture, the mean critical thermal minimum and the mean rate of water loss were lowest for lizards in the northern population. Furthermore, these traits acclimated to either temperature or humidity in a direction consistent with adaptive phenotypic plasticity. By contrast, metabolic rates varied among populations but did not conform to our prediction based on a latitudinal cline in temperature. Critical thermal maxima, endurances, and sprint speeds were similar among populations. Despite the idea that tropical lizards have limited capacity for acclimation, we found variation among invasive populations of brown anoles, which could have partially resulted from acclimation. This physiological variation within the invasive range raises questions about the roles of plasticity and adaptation in the success of the invasion.
Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, Rhode Island 02881; 2Department of Biology, Indiana State University, Terre Haute, Indiana 47809; 3School of Life Sciences, Arizona State University, Tempe, Arizona 85287.
Jason J
JJ
Kolbe
Joseph C
JC
Ehrenberger
Haley A
HA
Moniz
Michael J
MJ
Angilletta
D000818:Animals; D001481:Basal Metabolism; D003247:Conservation of Natural Resources; D003462:Cuba; D005260:Female; D005431:Florida; D005845:Georgia; D058865:Introduced Species; D008116:Lizards / Q000235:genetics / Q000502:physiology*; D008297:Male; D009043:Motor Activity; D014870:Water Loss, Insensible