The ecology of collective behavior

Abstract

Similar patterns of interaction, such as network motifs and feedback loops, are used in many natural collective processes, probably because they have evolved independently under similar pressures. Here I consider how three environmental constraints may shape the evolution of collective behavior: the patchiness of resources, the operating costs of maintaining the interaction network that produces collective behavior, and the threat of rupture of the network. The ants are a large and successful taxon that have evolved in very diverse environments. Examples from ants provide a starting point for examining more generally the fit between the particular pattern of interaction that regulates activity, and the environment in which it functions.

Figure 1. Patchiness in space and time.

(A) Uniform. (B) Patchy.

Figure 2. Effect of operating costs.

(A) Process that stops unless initiated by a positive event. (B) Process that continues unless stopped by a negative event.

Figure 3. Ring network.

(A) Ring network with flow in both directions. (B) When flow in one direction is interrupted, flow in the other direction facilitates recovery.