We have also ignored within‐host competition and thus evolution operating at the within‐host scale, but where malaria is endemic, multigenotype infections are the rule rather than the exception (e.g. Baruah, Lourembam, Sawian, Baruah, & Goswami, 2009; Juliano et al., 2010). Previous theoretical and experimental work shows that competition favours reproductive restraint (Greischar et al., 2016a; Greischar, Reece, et al., 2016; McKenzie & Bossert, 1998; Mideo & Day, 2008; Pollitt et al., 2011), so it is possible that our prediction of that same response in the face of drug treatment would remain unchanged. However, just as there is genetic variation for competitive ability (Bell, De Roode, Sim, Read, & Koella, 2006; de Roode, Helinski, Anwar, & Read, 2005; de Roode et al., 2005), there is likely to be genetic variation in sensitivity to drugs (and in P. falciparum, differentially sensitive genotypes may often share a host; e.g., Mideo et al. (2016)). If variation in drug sensitivity is unrelated to transmission investment, then it would alter the costs and benefits to different parasite genotypes of altering that investment. Modelling the dynamic consequences of competition and the interplay between different sources of resistance on the evolution of parasite life history would be an interesting route for future investigation. Importantly, there may also be genetic variation in the shape of the relationship between within‐host gametocyte densities and the probability of transmission to mosquitos. As far as we are aware, this relationship has been quantified only a few times and only for a few distinct strains (Bell et al., 2012; Huijben et al., 2010; Paul, Bonnet, Boudin, Tchuinkam, & Robert, 2007). While the qualitative shapes of these relationships remain the same, there are quantitative differences in their parametrization. We found that these differences did not alter our predictions (see Figure A.3 in Appendix A), but further empirical exploration of this relationship is warranted, as is theoretical investigation of how any quantitative changes in this relationship alter evolutionary predictions.