The Bogert Effect and environmental heterogeneity
The Bogert Effect and environmental heterogeneity
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博格特效应和环境异质性
作者：
Michael L. Logan;Jenna van Berkel;S. Clusella‐Trullas
进化生物学中的一个经典问题是，行为灵活性是加速还是阻碍了进化变化。后一种观点认为，行为减少了生物体所经历的环境状态的数量，并缓冲了生物体对选择的影响，这种观点被称为“博格特效应”，以生物学家查尔斯·博格特（Charles Bogert）的名字命名。博格特首次利用蜥蜴的数据推广了这一现象。当考虑到体温等特征时，博格特效应是普遍存在的，而体温在具有行为体温调节能力的物种中往往是跨空间不变的。然而，当操作温度的空间变化较低时，行为体温调节减弱或停止。我们比较了环境温度，温度调节行为，以及一套生理和形态特征之间的两个种群在南非的南部岩石agama （agama atra）经历不同的气候制度。这两个种群的个体都能有效地调节体温，在大部分活动周期内将体温保持在它们喜欢的温度范围内。然而，它们在较低体温下静息代谢率的热敏性和形态学上存在差异。我们的研究结果支持了一种普遍的观点，即温度调节行为可能会阻止野外活动体温等特征的分化，这些特征是在高环境异质性时期测量的。然而，我们表明，如果在环境同质的情况下进行选择，其他性状可能会自由分化。我们认为，博格特效应的重要性严重依赖于环境异质性的性质，因此在许多种群中，博格特效应与某些性状相关，而与其他性状无关。
A classic question in evolutionary biology is whether behavioral flexibility hastens or hinders evolutionary change. The latter idea, that behavior reduces the number of environmental states experienced by an organism and buffers that organism against selection, has been dubbed the “Bogert Effect” after Charles Bogert, the biologist who first popularized the phenomenon using data from lizards. The Bogert Effect is pervasive when traits like body temperature, which tend to be invariant across space in species that behaviorally thermoregulate, are considered. Nevertheless, behavioral thermoregulation decreases or stops when spatial variation in operative temperature is low. We compared environmental temperatures, thermoregulatory behavior, and a suite of physiological and morphological traits between two populations of the southern rock agama (Agama atra) in South Africa that experience different climatic regimes. Individuals from both populations thermoregulated efficiently, maintaining body temperatures within their preferred temperature range throughout most of their activity cycle. Nevertheless, they differed in the thermal sensitivity of resting metabolic rate at cooler body temperatures and in morphology. Our results support the common assertion that thermoregulatory behavior may prevent divergence in traits like field-active body temperature, which are measured during periods of high environmental heterogeneity. Nevertheless, we show that other traits may be free to diverge if they are under selection during times when environments are homogenous. We argue that the importance of the Bogert Effect is critically dependent on the nature of environmental heterogeneity and will therefore be relevant to some traits and irrelevant to others in many populations.