Comment by fsckboy

marginal effects are small, but it's where the integration and feedback add up or even multiply. the claim here is that the mitchondria are paying attention to their own marginal quantities which are quite small; the outsized effects if they are someplace will lie elsewhere. For example, sendentary life will lead to less muscle mass, which means fewer mitochondria overall, but that's not the individual mitochondria "noticing" anything.