'How does altruism evolve in animals?' could be the biggest mystery in the whole of evolutionary biology. How could co-operation and altruism evolve from the dog-eat-dog world of natural selection? One answer comes from observations of social creatures, especially meerkats and certain insects such as ants and bees.
There is a connection between altruism and relatedness – you are more likely to do good for someone who shares many of your genes. This works for social insects such as bees in which the female workers, all daughters of the queen, are sterile, but care for the queen’s progeny.
Because of their unusual system of genetic inheritance, the workers are much more closely related than, say, human siblings, and so will be more likely to care for the queen’s offspring than if they were their own. However, this can’t be the whole explanation, because some bees aren’t social but have this mode of inheritance, while many social animals, from termites to mammals, do not.
It’s been suggested that social behaviour, including altruism, has less to do with genetics than the environment and the evolutionary history of the species concerned, including the distribution of food and other factors.
This has provoked much ferocious debate. As for other causes, studies of ants and other animals show that hormones play a part in enforcing social structure. Other explanations come from game theory: computer models are created in which animals get rewards or punishments depending on whether they co-operate or ‘defect’ – that is, exploit others. In some games, defection appears to reap the most rewards in the short term, but co-operation can emerge as a long-term strategy.
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