Phenotypic Adaptation and Natural Selection in the Wild Rabbit, Oryctolagus cuniculus, in Australia

Abstract

(3) Genetic differences among regional populations were detected from the persistence of traits through two generations of rearing under standardized conditions. Differences in the shape of the body core were consistent with prior genetic adaptation to regional ambient temperature. Other genetic adaptations or founder effects caused divergence in size of the ears and pes. (4) The size of the ears differed adaptively among regional field populations, being longer in warmer climates, apparently because genetic differences interacted with phenotypic responses to heat. (5) The pinnae have thermoregulatory functions and responded phenotypically to ambient temperature during growth in two generations. In contrast, the pes lack a thermoregulatory role and grew independently of ambient temperature, but responded to other environmental factors.