From: Sent: Wednesday, November 27, 2013 12:25 AM To: Gordon Getty Cc: [email protected]; Alan Rogers; Robert Frank; Jeffrey Epstein Subject: degree of r and age Dear Gordon I very much like your slimmed down version of Hamilton/Fisher. Certainly collapsing the main equation by N=1 is obvious. Somewhat less so is the matter of defining a benefit (B) i.e. an increase in reproductive success, as a change in one's reproductive value, which seems like a more permanent character. In one sense yes: it has just gone up, but does the general, let us say declining in older people rule, still not apply?—and is it bumped throughout by the same benefit recently transferred ? When I explicitly set out to build a theory of the family I knew the key variables were degree of relatedness, sex and age—yet I never reached a proper synthesis with the latter. Here I would trust Alan Rogers more than myself; likewise, David Haig has contributed the following, which also references Alan: Ronald Lee has developed a model of intergenerational transfers that has some interesting properties. The problem is that his model is implicitly one of clonal asexual reproduction (r = 1 for all transfers among individuals). I am not sure whether anyone has achieved a general model for transfers among relatives which is what Gordon is working at. Lee, R. (2008) Sociality, selection, and survival: simulated evolution of mortality with intergenerational transfers and food sharing. Proceedings of the National Academy of Sciences, USA 105: 7124-7128. Lee, R. D. (2003) Rethinking the evolutionary theory of aging: transfers, not births, shape senescence in social species. Proceedings of the National Academy of Sciences, USA 100: 9637-9642. and Alan Rogers has a commentary: Rogers, A. R. (2003) Economics and the evolution of life histories. Proceedings of the National Academy of Sciences, USA 100: 9114-9115. Note absence of parent-offspring conflict. I will write you later re