Data from: Genetic variation in aggregation behaviour and interacting phenotypes in Drosophila

Aggregation behaviour is the tendency for animals to group together which may have important consequences on individual fitness. We used a combination of experimental and simulation approaches to study how genetic variation and social environment interact to influence aggregation dynamics in Drosophila. To do this, we use two different natural lines of Drosophila that arise from a polymorphism in the foraging gene (“rovers” and “sitters”). We placed groups of flies in a heated arena. Flies could freely move towards one of two small, cooler refuge areas. In groups of the same strain, sitters had a greater tendency to aggregate. The observed behavioural variation was based on only two parameters: the probability of entering a refuge and the likelihood of choosing a refuge based on the number of individuals present. We then directly addressed how different strains interact by mixing rovers and sitters within a group. Aggregation behaviour of each line was strongly affected by the presence of the other strain, without changing the decision rules used by each. Individuals obeying local rules shaped complex group dynamics via a constant feedback loop between the individual and the group. This study could help to identify the circumstances under which particular group compositions may improve individual fitness through underlying aggregation mechanisms under specific environmental conditions.聚集行为（aggregation behaviour）指动物集群活动的倾向，该行为对个体适合度（individual fitness）可能产生重要影响。本研究结合实验与模拟仿真方法，探究遗传变异与社会环境的交互作用如何影响果蝇（Drosophila）的聚集动力学特征。为此，我们选取了两类源自取食基因（foraging gene）多态性的天然果蝇品系：“漫游者（rovers）”与“滞留者（sitters）”。我们将果蝇群置于加热实验箱中，果蝇可自由移动至两个小型低温庇护区域中的任意一个。在单一品系的果蝇群中，滞留者表现出更强的聚集倾向。实验观测到的行为差异仅由两个参数决定：进入庇护区域的概率，以及基于当前种群数量选择庇护区域的倾向。随后，我们通过将漫游者与滞留者混合饲养，直接探究不同品系间的交互作用机制。两类品系的聚集行为均会因另一品系的存在而受到显著影响，但二者各自的决策规则并未发生改变。遵循局部行为规则的个体，通过个体与群体间持续的反馈环路，塑造出复杂的群体动态特征。本研究有助于明确在特定环境条件下，何种群体结构可通过潜在的聚集机制提升个体适合度。