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compromising the organismal nature of the colony. But a closer look at traditional individuals shows that they too have some internal conflicts (Burt and Trivers, 2006; Haig, 1996; Hurst et al., 1996). For example, selfish genetic elements such as transposons can not only make up large parts of genomes, using expensive resources and extending replication times, but they can also interfere with the functioning of the individual (Burt and Trivers, 2006). The conflicts within cooperative social insect colonies have helped biologists to identify conflict in other cooperative entities, for example the conflicts between maternal and paternal genes mediated by genomic imprinting (Haig, 2000).

A HOUSE DIVIDED

A small stingless bee out in a tropical forest might seem like any other animal as it searches for food to survive and reproduce. Upon closer inspection, a more complex picture would emerge. The foraging bee is a member of a complex colony inside a tree hollow. Within, there is a citadel of wax with a smooth protective skin surrounding fat peripheral cells that contain honey and pollen, and central combs of smaller brood cells, all held together and supported by a lacy network of wiry wax struts. Small female worker bees are busy everywhere, bringing in food and propolis, adding to the structures, cleaning, and guarding. But the focus of their attention is a single female, the queen, with a greatly distended abdomen and worn, useless wings. A throng of workers surrounds the queen so closely as to slow her approach to an empty cell. At the empty cell, the queen antennates the inside, as if checking its construction. The workers dart in and out, at one time crouching before the queen, at other times rearing up before her. This agitated ballet ends with the queen stroking the workers, who then regurgitate larval food into the cell, one after the other, until it is full. Then the queen lays a single egg that floats on the provisions. When she leaves, the workers carefully bend the collar of wax over and close the cell. The egg will hatch and grow to adulthood undisturbed but benefiting from the workers’ attention to climate control and defense (Zucchi, 1993).

This scene summarizes what is special about social insects: complex communication and integration of behavior, and individuals caring for the offspring of another. The colony as a whole appears to have the kind of integration and common purpose normally associated with individual organisms, with the parts subservient to the whole. The stingless bee colony is highly organized, both structurally and behaviorally. The provisioning and oviposition process seems to have an almost clock-like precision, with elaborate coordination between the queen who lays the egg and the workers who build and provision the cell. This process only



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