Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom.
Am Nat. 2006 Jun;167(6):837-52. doi: 10.1086/503445. Epub 2006 Apr 13.
Recent theory suggests that much of the wide variation in individual behavior that exists within cooperative animal societies can be explained by variation in the future direct component of fitness, or the probability of inheritance. Here we develop two models to explore the effect of variation in future fitness on social aggression. The models predict that rates of aggression will be highest toward the front of the queue to inherit and will be higher in larger, more productive groups. A third prediction is that, in seasonal animals, aggression will increase as the time available to inherit the breeding position runs out. We tested these predictions using a model social species, the paper wasp Polistes dominulus. We found that rates of both aggressive "displays" (aimed at individuals of lower rank) and aggressive "tests" (aimed at individuals of higher rank) decreased down the hierarchy, as predicted by our models. The only other significant factor affecting aggression rates was date, with more aggression observed later in the season, also as predicted. Variation in future fitness due to inheritance rank is the hidden factor accounting for much of the variation in aggressiveness among apparently equivalent individuals in this species.
最近的理论表明，在合作动物社会中存在的个体行为的广泛差异，可以通过未来直接适应度的变化，或者说遗传概率来解释。在这里，我们开发了两个模型来探索未来适应度的变化对社会攻击性的影响。这些模型预测，朝着继承顺序最前面的个体的攻击率将最高，在更大、更具生产力的群体中，攻击率也会更高。第三个预测是，在季节性动物中，随着获得繁殖位置的时间耗尽，攻击性将会增加。我们使用模型社会物种——纸黄蜂 Polistes dominulus 来检验这些预测。我们发现，与我们的模型预测一致，攻击的“表现”（针对较低等级的个体）和攻击的“测试”（针对较高等级的个体）的频率都随着等级的下降而降低。唯一另一个影响攻击率的重要因素是日期，随着季节的推移，观察到的攻击行为也会增加。由于继承等级而导致的未来适应度的变化是造成该物种中明显相同的个体之间攻击性差异的主要隐藏因素。
