Brenner claims "Animal gene sets have been subject to genetic selections for guile, strength and famine-resistance but have not been directly selected for longe

Brenner claims "Animal gene sets have been subject to genetic selections for guile, strength and famine-resistance but have not been directly selected for longevity because". This is case 2 in my classification. He writes, "Indeed, experiments done in flies that were selected for the ability to reproduce late in life suggest that hundreds or thousands of genes, not single dominantly acting genes, are modified to allow every organ system to function better over time in the resulting long-lived flies (Burke et al., 2010)." The case of sirtuin genes, however, is disctintly different from this. The hypothesis there is that increased expression of sirtuins increases longevity. This is a change to the epigenome, not to the genetic content itself, which is what is what Brenner comments on. Also, what this says is not that "evolution never had any reason to favour another approach", but that evolution (at least in this controlled environment) was not able to stop aging. Perhaps you have other data to support that claim. Also, what this says is not that "evolution never had any reason to favour another approach", but that evolution (at least in this controlled environment) was not able to stop aging. Perhaps you have other data to support that claim. From the perspective of maximizing reproduction, maximizing fertile population is oviously ideal. Surely, if it's possible for a member of the species that is fertile to continue to reproduce and live longer, this would increase the species' overall reproductive capacity. Obviously, post-reproductive age individuals do not have this benefit. However, it doesn't seem improbable that loss of reproductive ability is caused by aging. I think that the tradeoff you mention between reproductive age fitness would make sense in the context of other adversity though. If survival in general is very difficult, surviving long enough to reproduce, reproducing as fast as possible, and being able to survive long enough to finish the process while it's placing various stressors on your body is desirable.