The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually ...The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually have longer tails and limbs, while these traits tend to be shorter in individuals from cold climates. We examined body size variation in an endemic Chinese lizard Phrynocephalus theobaldi along a broad elevational gradient （3,600-5,000 m on the Qinghai-Tibetan Plateau）. Female body size showed a U-shaped cline, decreasing with increased elevation within the range 3,600-4,200 m, but increasing at eleva- tions 〉 4200 m. Male body size continued to increase with increasing elevations. Both sexes showed an increased pattern of ex- tremity length with elevation that does not conform to Allen＇s rule. Limb length and tail length increased along the elevational gradients. In terms of color pattern, an abdominal black speckled area appears at elevations 〉4,200 m. This trait increases in size with increased elevation. Unlike most studies, our results indicated that annual sunshine hours corresponding to the activity pe- riod of the lizards could play an important role on the positive body size cline in environments at very high elevations 〉 4200 m展开更多
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （31372183, 31000950）. We thank the Chinese National Climate Data Center for his- torical climatic data, and the Tibetan government for permis- sion to collect specimens. We thank R. Brown, S. Mullin for their kind detailed reviews on the manuscript before submis- sion, and appreciate R. Brown for his extensive help in im- proving the language of the manuscript before publication. We also thank S. Meiri and another anonymous referee for their kind revisions or suggestions on our submitted manuscript.
文摘The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually have longer tails and limbs, while these traits tend to be shorter in individuals from cold climates. We examined body size variation in an endemic Chinese lizard Phrynocephalus theobaldi along a broad elevational gradient （3,600-5,000 m on the Qinghai-Tibetan Plateau）. Female body size showed a U-shaped cline, decreasing with increased elevation within the range 3,600-4,200 m, but increasing at eleva- tions 〉 4200 m. Male body size continued to increase with increasing elevations. Both sexes showed an increased pattern of ex- tremity length with elevation that does not conform to Allen＇s rule. Limb length and tail length increased along the elevational gradients. In terms of color pattern, an abdominal black speckled area appears at elevations 〉4,200 m. This trait increases in size with increased elevation. Unlike most studies, our results indicated that annual sunshine hours corresponding to the activity pe- riod of the lizards could play an important role on the positive body size cline in environments at very high elevations 〉 4200 m
