I like another theory I read recently: That it's because women's mitochondria are more fine-tuned to their nuclear genome: "The inheritance of mitochondria is

I like another theory I read recently: That it's because women's mitochondria are more fine-tuned to their nuclear genome: "The inheritance of mitochondria is asymmetric: you only get them from your mother, and your father makes no mitochondrial contribution at all. Your father’s mitochondrial contribution dies with him and is not passed on. What does that mean? It means that there can be no selection to fine tune mitochondria to the male nuclear genome." Mitochondria are extrmely important to the cell and have been linked to many effects of aging. The reasoning above suggests that mitochondria work more poorly in males. And indeed, the paper (linked below) explains that in fruit flies, mitochondrial genes in males are expressed with much higher variability than females. Your two links depend on human biology, but early male death is a much more general phenomenon. Males die earlier in the vast majority of animals (with gender). This idea could explain it. http://scienceblogs.com/pharyngula/2013/02/06/mothers-curse/ http://scienceblogs.com/pharyngula/2013/02/06/mothers-curse/ http://www.ncbi.nlm.nih.gov/pubmed/23281153 http://www.ncbi.nlm.nih.gov/pubmed/23281153