Even when individuals do not have offspring of their own, membership in a group can increase the chances of survival and the chance of passing on their own genes. That shows a new study. The apparent disinterest in raising young animals from other parents can be explained by natural selection, because one’s own genetic fitness may increase as a result.
“In many animal societies, young animals are cared for, nurtured and protected not only by their parents, but also by other members of the group,” say Austrian ethologist Michael Taborsky and Irene García-Ruiz of the Institute of Ecology and Evolution of the la University of Bern. Their study was published in the journal Science Advances.
“As long as siblings are involved, the evolution of such interbreeding can easily be explained by relative selection. Transmission of genetic disposition is just as efficient through full siblings as it is through one’s own offspring.”
“Determined by environment”
According to simulation models, there is also a biological explanation for why caregivers take care of unrelated foster children. This is the case, for example, when they come from members of the immigrant group. “This happens in many societies, from social insects to humans. Then, the enlargement of the group increases one’s chances of survival.
According to Taborsky and García-Ruiz, which of the two selection mechanisms prevails in a group is determined by the environment: under favorable environmental conditions, kin selection is of great importance for the emergence of altruistic behavior.
Age also influences
“However, in a dangerous environment, kinship does not play a significant role in the evolution of altruistic care assistance for offspring,” says Taborsky: So one’s own safety advantage through increased group size a through cooperation is more important for the evolution of non-parental care. brood care.
The age of individuals also plays a role in how best to increase their own fitness by acting altruistically, i.e. caring for younger members of the group and thus increasing group size, or moving to produce his own offspring. In an environment with good food supplies and few predators, individuals should leave the group early to maximize their genetic fitness, but in a dangerous environment only at an older age to carry out altruistic brood care “at home” during a longer period of time. weather.