The social organization of animals can affect life span. On the 2nd, the reporter learned from the Institute of Zoology of the Chinese Academy of Sciences that using the phylogenetic comparative analysis method, the researchers of the Institute analyzed nearly 1000 mammals and found that the gregarious species live longer than the solitary species. Relevant research results were published online in the journal Nature Communication. Mammals have various forms of social organization, such as living alone, living in pairs and various forms of social life. The longest life span of different mammalian species is quite different. For example, some shrews can only live for 2 years at most, while bowhead whales can live for more than 200 years at most. Previously, academic research on individual species such as baboons found that individuals with strong social connections live longer than individuals with weak social connections. At the same time, previous studies have also found that gregarious living can reduce the risk of predation and hunger, which helps to increase the life span of mammals. "However, the cross-species comparative study of social organization and life span is still very limited. It is not clear whether there is a co-evolutionary relationship between the social organization and maximum life span of mammals." Zhou Xuming, the co-author of the paper and researcher of the Institute of Zoology, Chinese Academy of Sciences, said frankly that clarifying the molecular mechanism of the evolutionary relationship between mammalian sociality and life span is very important for understanding mammalian evolution, But these molecular mechanisms have not been clear. This time, researchers analyzed 974 kinds of mammals and compared the relationship between life span and three social organizations, namely, living alone, living in pairs and living in groups. "The social species we analyzed include Asian and African elephants, ring-tailed lemurs, mountain zebras and chrysanthem-headed bats, and the solitary species include dugongs, aardvarks, and East American chipmunks," said Zhou Xuming. The study found that the life span of social species is generally longer than that of solitary species. For example, the northern short-tailed shrew of solitary animals and the horseshoe chrysanthemum head bat of social animals have similar weight, but the longest life span is about 2 years and 30 years respectively. "This supports the argument that there is co-evolution between mammalian social organization and life span," Zhou Xuming stressed. The researchers also conducted transcriptome analysis on 94 mammalian species and identified 31 genes and related pathways involving hormones and immunity, which are generally related to social organization and life span. Zhou Xuming said that this study shows that the evolution of life span depends on the evolution of social organizations, that is, in mammals, there is a correlation between social organizations and life span. At the same time, this study also laid an important foundation for clarifying the molecular mechanism behind the evolutionary relationship between social life and life span. (Outlook New Era)