Men and the wall of death: evolutionary explanation

https://www.ncbi.nlm.nih.gov/pubmed/17726515


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1949148/bin/pone.0000785.g001.jpg

The wall of death.

This figure shows the force of selection by age, S(x), as a fraction of the force of selection at birth, S(0), as described by Hamilton using female-only demography. (a) Hamilton's one-sex force of selection at age x (shown relative to its value at birth) falls to zero with the decline of remaining survival-weighted female reproduction. b is the inverse of the top panel. In mutation-selection balance, the frequency of deleterious mutant alleles is expected to be proportional to 1/S, where S is the force of selection for a dominant or semi-dominant allele. The inverse of the force of selection is an indicator of age-specific mortality. The rapid increase in mortality at female menopause is the ‘wall of death.’