|
A new study by biologists at the University of Edinburgh explains why babysitting occurs in some animal species but not in others. Research published in the current edition of Science suggests that when conditions are hard, and animals must cooperate to survive, individual animals are more inclined to babysit and help near relatives who have offspring. The biologists studied mammals and birds that live in family groups – including meerkats, dwarf mongooses and kookaburras – where there are helpers who assist in the childcare of others, instead of raising their own young. They found that preferential assistance of relatives is most common among species such as pied kingfishers and long-tailed tits where helping provides a huge benefit to the survival of young. In contrast, in a species like the kookaburra, such help provides negligible benefit so there is little advantage to be gained from relatives being given help. But the study suggests that cooperation within certain species can be explained by forces more akin to Richard Dawkins’ concept of the ‘selfish gene’, rather than more generous forces being at work. Cooperation is beneficial within certain species because individuals share a high proportion of genes with their relatives, and so by helping them raise young, they are still maximising their genetic contribution to the next generation. Dr Stuart West, of the University of Edinburgh’s Institute of Cell, Animal & Population Biology, said: “Cooperative breeding in animals is a controversial area of evolutionary biology. There has been much debate over the extent to which cooperative breeding can be explained by kin selection – when individuals gain fitness through the reproduction of relatives. While some have claimed kin selection is important, others have argued against it. “Debate has been fuelled by the variations found in studies which focus on the extent to which individuals preferentially help relatives. Our study has resolved this problem by explaining these variations across different species. We have shown that preferential helping of relatives is more common in species where helping brings benefits – in other words, blood is often thicker than water … but not in every case.”
|
