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）的聚集动力学特性。
为此，我们选用了两种源自觅食基因（foraging gene）多态性的果蝇自然品系：漫游型（rovers）与滞留型（sitters）。我们将果蝇群组放置于加热试验场（arena）中，果蝇可自由移动至两个小型凉爽避难区域中的任意一个。在同品系群组中，滞留型果蝇表现出更强的聚集倾向。观测到的行为变异仅由两个参数决定：进入避难所的概率，以及基于当前在场个体数量选择避难所的倾向。
随后，我们通过将漫游型与滞留型果蝇混合组建群组，直接探究不同品系间的交互作用模式。各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，通过个体与群组间的持续反馈环路，构建出复杂的群组动态特性。
本研究有助于明确在特定环境条件下，何种群组组成可通过潜在的聚集机制提升个体适合度。