by Bert Hölldobler, by Edward O. Wilson
Harvard University Press (Belknap Press), 732 pp., $65.00
I remember, some years ago, visiting E.O. Wilson at Harvard. For some reason, he had to leave the room for a few minutes, and during his absence I enjoyed watching a colony of weaver ants with which—I almost wrote with whom—he shared his office. At first sight their movements appeared incoherent and disorganized, but, as I watched, it became clear that they were moving a large prey item toward their nest. This impression of apparent incoherence and actual directedness is often experienced by those who, like me, are unfamiliar with ants. It is similar to the impression one receives looking down a microscope at the cells of a developing embryo. It would also be the perception of a visiting Martian observing the people in a large railway station during the rush hour. This analogy between developing organism, insect society, and human city is not new. It is very much in the minds of the authors of The Ants, as shown for example by their frequent use of the term “superorganism” for an ant colony. But it is an analogy we do not quite know what to do with: How should we make use of it, in our imagination and our analysis?
Let us first be clear that the analogy is a real one. For example, in each case the units of which the whole is made show a division of labor, whether into nerve cells, muscle cells, and fibroblasts, or into reproductives, workers, and soldiers, or into bricklayers, carpenters, and professors. In each case, there must be communication between the units to ensure integration. Perhaps most important, there is a common feature of the evolution of the three systems. In each case, the units were once noncolonial: multicellular organisms are descended from single-celled ones; the ancestors of the ants were solitary wasp-like insects; and we are descended, in the sufficiently distant past, from mammals in which no social bond existed beyond that between mother and child. So to understand the social wholes, we must understand how they evolved from solitary and independent units.
In view of these parallels, the first point, triumphantly made by Bert Hölldobler and E.O. Wilson, is that the proper study of ants is ants. It is not just that ants are ecologically important. It is estimated, for example, that one third of the animal biomass of the Amazonian rain forest is composed of ants and termites, and other ecological habitats may not be very different. Equally important, ants display an astonishing range of structure and behavior. Some of the most bizarre examples concern the modification of individual worker ants to perform tasks that in human society would be performed by inanimate tools. In honey-pot ants, liquid food is stored in grotesquely swollen workers, each the size of a pea, that hang from the ceiling of the nest chamber. In weaver ants, the nest is made by weaving leaves together with silk. Silk is produced by the grub-like larvae, but in some cases …