Funny photographs reveal why women really live longer than men

The biological basis for female longevity is clear: The female of every species outlives the male with very few exceptions. Having two “X” chromosomes provides women with a backup when a genetic mutation occurs on one of the genes, while men only have a single “X” chromosome to express all their genes, whether damaged or not. Perhaps this genetic reserve allows a greater repertoire of effective neural, endocrine, and immune responses to potentially deleterious environmental demands.