Chapter 7 - Ants

Abstract

This chapter discusses evolution of ants, how do they communicate, social organization, and social diversity. Ecologically, ants are very successful. One of the reasons that ants are so successful is that their colonies have extremely efficient divisions of labor: they evolved factories millions of years before we reinvented them. Another reason is that they can modify their immediate environment to suit themselves. One of the most dramatic traits associated with the division of labor among the ants is physical polymorphism, which is the presence of different physical worker forms within the same colony. Such worker polymorphism is now known to be associated with the differential growth rates of different putative tissues and body parts during the pre-adult stages. Ants have diverse systems of communication, but by far the most important medium for signaling involves the chemicals known as pheromones. Self-organization, collective intelligence, and decision making are another important traits of ants. A simple and very intuitive example of how ants use self-organization is found in their ability to select shortcuts. Certain ants can select the shortest paths to food sources. Indeed, where there is a short and a long path to the same food source, the decision-making mechanism can be surprisingly simple. All the ants lay attractive trail pheromones and such pheromones are reinforced more rapidly on the shorter path simply because that path is shorter and quicker.