Social insects – superorganisms or just superb organisms? Bert Hölldobler and Edward O. Wilson: The Superorganism – the Beauty, Elegance, and Strangeness of Insect Societies. W.W. Norton: London and New York. ISBN 978 0 393 06704 0

division of labour (reproductive and sterile castes), overlapping generations and non-reproductive animals caring for the young. The second and stricter definition applies only to colonies of an advanced state of eusociality, in which reproductive conflicts among colony members are diminished such that workers are selected to maximise colony efficiency. A third definition states: " a superorganism is a colony of individuals self-organized by division of labour and united by a closed system of communication. " A fourth definition follows in the glossary: " a superorganism is a society that possesses features of organization analogous to the physiological properties of single organisms. " Interestingly, the authors themselves appear to disagree over the definition of a superorganism — Wilson applies the term to any type of eusocial organization, while Hölldobler prefers to use the term for species in which workers have partly lost their reproductive ability. This disagreement and the multitude of definitions provided betray the fact that it is actually quite unclear what a superorganism is — somewhat worrisome given the book's title. In line with the third definition, Hölldobler and Wilson present a wealth of fascinating information on mechanisms of self-organization, division of labour, communication and nest architecture; some highlights are: the explanation of self-organisation — whereby the sum of simple decision algorithms of individual ants leads to assembly of the colony without any superior command; the division of labour in bee hives where workers perform nursing, food processing and foraging tasks in an age-dependent manner governed by differential gene expression and hormone levels; and the famous waggle dance of honey bee foragers, which communicates direction and distance of a newly discovered food source. From an evolutionary perspective, however, one is tempted to ask what this detailed mechanistic information tells us about why these behavioural traits have evolved in the first place. The authors claim that they do answer this question, and they take these mechanistic findings as evidence for natural selection acting at the colony level, which they propose acts to maximise the colony's genetic fitness. " Man, according to the Stoics, ought to regard himself, not as something separated and detached, but as a citizen of the world, a member of the vast commonwealth of nature. To the interest of this great community, he ought at all times to be willing that his own little interest should be sacrificed. " Adam Smith (1759). The Theory of Moral Sentiments …