Evolution: Animals inherit their parents' social connections

Models of the social networks of animals that incorporate a high degree of inheritance of social connections from parents to offspring resemble real-world animal social networks, finds a study in Nature Communications this week. The authors model the structure of social networks and inheritance of social positions in the animal kingdom and find that their models match the properties of real-world social networks of animals such as hyenas, rock hyraxes, bottlenose dolphins and sleepy lizards.

The structure of social networks (for example, the number of social interactions and the degree to which interactions are clustered into sub-groups within the network) can influence important evolutionary and ecological processes such as the flow of information or the spread of diseases. However, the underlying causes of the structure of social interactions in the animal kingdom are poorly understood, and prior attempts to model the formation of social networks have been unable to replicate their complex structure.

Erol Akcay and colleagues modelled hypothetical social networks assuming that newborns could either inherit their mothers’ connections or form ties with random individuals. In the simulations with high social inheritance, a newborn’s position in the social network and the number of contacts it formed were correlated with the same traits in the mother. When the models included a high degree of social inheritance, the simulated networks closely matched published real-world social networks for four animal species: spotted hyena (Crocuta crocuta), rock hyrax (Procavia capensis), bottlenose dolphin (Tursiops spp.) and sleepy lizard (Tiliqua rugosa).

Whether or not these inherited social contacts persist into adulthood remains an open question, but these results suggest that social inheritance is an important driver of network structure in natural communities.