Department of Biology, University of California at Riverside, Riverside, California 92521-6000, USA.
Evolution. 2011 Jan;65(1):43-51. doi: 10.1111/j.1558-5646.2010.01112.x. Epub 2010 Sep 29.
Many ectotherms show crossing growth trajectories as a plastic response to rearing temperature. As a result, individuals growing up in cool conditions grow slower, mature later, but are larger at maturation than those growing up in warm conditions. To date, no entirely satisfactory explanation has been found for why this pattern, often called the temperature-size rule, should exist. Previous theoretical models have assumed that size-specific mortality rates were most likely to drive the pattern. Here, I extend one theoretical model to show that variation in size-fecundity relationships may also be important. Plasticity in the size-fecundity relationship has rarely been considered, but a number of studies show that fecundity increases more quickly with size in cold environments than it does in warm environments. The greater increase in fecundity offsets costs of delayed maturation in cold environments, favoring a larger size at maturation. This can explain many cases of crossing growth trajectories, not just in relation to temperature.
许多变温动物表现出交叉生长轨迹，这是对饲养温度的一种可塑性反应。因此，在较凉爽条件下生长的个体生长速度较慢，成熟较晚，但在成熟时比在温暖条件下生长的个体更大。迄今为止，还没有找到一个完全令人满意的解释来说明为什么会存在这种模式，通常被称为温度-体型规则。以前的理论模型假设，特定大小的死亡率最有可能导致这种模式。在这里，我扩展了一个理论模型，表明大小-繁殖力关系的变化也可能很重要。大小-繁殖力关系的可塑性很少被考虑，但许多研究表明，在寒冷环境中，繁殖力随体型的增加比在温暖环境中更快。在寒冷环境中，繁殖力的更大增加抵消了成熟延迟的成本，有利于在成熟时达到更大的体型。这可以解释许多交叉生长轨迹的情况，而不仅仅是与温度有关。
