Williams’ intuition about extrinsic mortality is irrelevant

Williams’ [ 1 ] model is presented as a general description of how selection favours age-specific survival in an age-structured population, but it has been falsified soundly on theoretical grounds. As a better model, namely Hamilton’s [ 2 ], exists, there is no legitimate scientific reason to test Williams’ model further. If Williams’ predictions are supported empirically, then these results are coincidental and not for the reasons imagined by Williams [ 3 ]. da Silva [ 4 ] appears willing to consider coincidence as intuition. The crux of his argument appears to rest on two claims, but these are based upon misrepresentations of Williams’ model and the findings of later models of ageing that explore the effects of density dependence.