Evolution of raised guarding behaviour in meerkats, Suricata suricatta
In this article I will first briefly describe meerkats and their social behaviours and then examine the possible mechanisms by which the cooperative raised guarding behaviour of the meerkats may have evolved. I will look at the theoretical and empirical problems of applying these theoretical models to the evolution of cooperative guarding behaviour in meerkats and try to see if the evidence points conclusively to any one of the possible mechanisms examined. I will discuss kin selection, reciprocal altruism, Zahavi's handicap principle, group selection and Bednekoff's direct benefits model. Kinship selection is a gene level selection, reciprocal altruism, Zahavi's handicap principle and direct benefits model are all individual level selection models and group selection is selection at the group level so natural selection may have operated on three different levels on the trait of raised guarding. I will not make a distinction between the initial emergence and spread and the current maintenance of the behaviour. It may be sustained by the same mechanisms but this is not necessarily so and the mechanisms acting to maintain the behaviour may well be different from those that favoured its original emergence and spread.