Center for Social Dynamics and Complexity, Arizona State University, Tempe, 85287, USA.
Am Nat. 2010 Oct;176(4):501-10. doi: 10.1086/656266.
The negative allometric scaling of metabolic rate with body size is among the most striking patterns in biology. We investigated whether this pattern extends to physically independent eusocial systems by measuring the metabolic rates of whole functioning colonies of the seed-harvester ant Pogonomyrmex californicus. These intraspecific scaling data were compared to the predictions of an additive model developed to estimate collective metabolic rates. Contrary to the prediction of the additive model, colony metabolic rate allometry resembled the pattern commonly observed interspecifically for individual organisms, scaling with colony mass(0.75). Among the same-aged colonies, net growth rate varied by up to sevenfold, with larger colonies exhibiting higher net growth efficiency than smaller colonies. Isolated worker groups exhibited isometric metabolic rate scaling, suggesting that the social environment of the colony is critical to regulating individual patterns of work output. Within the social environment, individual worker locomotor velocities exhibited power-law distributions that scaled with colony size so that larger colonies exhibited a greater disparity between active and inactive ants than did smaller colonies. These results demonstrate that behavioral organization within colonies may have a major influence on colony-level metabolism and in generating intraspecific variation in growth trajectories.
代谢率与体型的负异速生长是生物学中最显著的模式之一。我们通过测量加利福尼亚种子采集蚁 Pogonomyrmex californicus 的整个功能群体的代谢率，来研究这种模式是否扩展到物理上独立的真社会性系统。这些种内尺度数据与为估计集体代谢率而开发的加性模型的预测进行了比较。与加性模型的预测相反，群体代谢率的异速生长模式类似于通常在个体生物中观察到的种间模式，与群体质量（0.75）成比例。在同年龄的群体中，净增长率变化可达七倍，较大的群体比较小的群体表现出更高的净增长率效率。分离的工蚁群体表现出等代谢率的缩放，这表明群体的社会环境对于调节个体的工作输出模式至关重要。在社会环境中，个体工蚁的运动速度表现出幂律分布，与群体大小成比例，因此较大的群体比较小的群体表现出活跃和不活跃蚂蚁之间更大的差异。这些结果表明，群体内的行为组织可能对群体水平的代谢和产生生长轨迹的种内变异有重大影响。
