Quantifying the role of sexual selection and kin selection in the evolution of aging

Aging is an evolutionarily labile trait that is likely shaped by a diversity of sources of natural selection. Two such mechanisms are sexual selection, or selection caused by competition among members of one sex for reproductive access to members of the other, and kin selection, which can be thought of selection arising from associations between fitness and social interactions. While various models have been used to argue for (or against) their importance in the evolution of aging, strategies for direct measurements of these selective forces are lacking. I will discuss my efforts to extend phenotypic selection methods to study populations with age structure. I will illustrate my findings thus far by describing sources of selection that have acted to promote post-reproductive female survival in a 19th century population of humans from the Western United States.