Fig. 1

Flocking algorithm and rules. Agents (boids) are shown as triangles, interactions as dashed lines, and the radius of perception as differently colored circles depending on the vector considered. Alignment and cohesion reinforce flocking behavior while repulsion disrupts it. In alignment (green), a boid will adjust its trajectory to match congruent flockmates. In cohesion (green), a given boid moves toward the center of mass of all congruent flockmates within its field of vision. In separation (yellow), all boids maintain a minimum distance from one another regardless of whether they are congruent or incongruent. Cohesion, alignment, and separation are the core forces in Reynolds’ original flocking algorithm. We have added repulsion (red) which operates between an agent’s field of vision and the smaller, concentric circle describing its radius of separation. The magnitudes of alignment, cohesion, and repulsion are a function of the phylogenetic distance between the agents as described in the implementation