Vanhooydonck B, Van Damme R, Van Dooren T J, Bauwens D
Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
Physiol Biochem Zool. 2001 Nov-Dec;74(6):937-45. doi: 10.1086/324749.
To understand the evolution of biological traits, information on the degree and origins of intraspecific variation is essential. Because adaptation can take place only if the trait shows heritable variation, it is important to know whether (at least) part of the trait variation is genetically based. We describe intra- and interindividual variation in three performance measures (sprint speed, climbing, and clambering speed) in juvenile Gallotia galloti lizards from three populations and examine how genetic, environmental (incubation temperature), and ontogenetic (age, size) effects interact to cause performance variation. Moreover, we test whether the three performance traits are intercorrelated phenotypically and genetically. Sprint speed is highest in juveniles incubated at the lowest temperature (26 degrees C) irrespective of population. Climbing speed differs among populations, and the differences persist at least until the lizards are 30 wk old. This suggests that the three populations experience different selective pressures. Moreover, mass, snout-vent length, and hindlimb length seem to affect climbing performance differently in the three populations. The variation in sprinting and climbing ability appears to be genetically based. Moreover, the two performance traits are intercorrelated and thus will not evolve independently from each other. Clambering speed (i.e., capacity to climb up an inclined mesh) varies among individuals, but the origin of this variation remains obscure.
为了理解生物性状的进化，关于种内变异程度和起源的信息至关重要。因为只有当性状表现出可遗传变异时适应才会发生，所以了解（至少）部分性状变异是否基于基因是很重要的。我们描述了来自三个种群的幼年加那利岛蜥蜴（Gallotia galloti）在三种性能指标（短跑速度、攀爬和攀爬速度）上的个体内和个体间变异，并研究了基因、环境（孵化温度）和个体发育（年龄、大小）效应如何相互作用导致性能变异。此外，我们测试了这三种性能性状在表型和基因上是否相互关联。无论种群如何，在最低温度（26摄氏度）下孵化的幼体短跑速度最高。攀爬速度在不同种群间存在差异，且这种差异至少持续到蜥蜴30周龄。这表明这三个种群经历了不同的选择压力。此外，体重、吻肛长度和后肢长度似乎在这三个种群中对攀爬性能的影响有所不同。短跑和攀爬能力的变异似乎是基于基因的。此外，这两种性能性状相互关联，因此不会彼此独立进化。攀爬速度（即爬上倾斜网的能力）在个体间存在差异，但其变异的起源仍不清楚。
