Study Links Evolution of Longevity, Social Organization in Mammals

In Nature Communications, investigators from China and Australia look at gene expression patterns in mammalian brains that may help explain the apparent correlation between longevity and social organization in mammals. With a comparative phylogenetics look at 497 solitary mammalian species, 115 pair-living species, and 412 species of mammals known for living in groups — along with an analysis of the rates of transition between these social structures — the team saw an association between mammalian social structures and longevity, with group-living species often outliving mammalian species with more solitary lifestyles. To begin unearthing genes and pathways contributing to this relationship, the authors subsequently analyzed brain RNA sequence data from 94 mammals, adjusting for size, ecology, and other traits to better understand the evolution of lifespan and social structures. "We show that group-living species lived longer than solitary species," the authors write, "and identify 31 genes, hormones, and immunity-related pathways involved in the correlated evolution of social organization and longevity.