Fig. 9

Pathway 7 Biodiversity: Upon population suppression of Anopheles gambiae via gene drive, its niche could be occupied by competitor species that could cause suppression of a valued species to affect ecosystem services. For this potential harm, the valued species could be reduced in density via two potentially countervailing effects (see illustration). A, X and Y denotes An. gambiae, species X and valued species Y, respectively. Size of white circles indicates notional population density of species. Green arrows indicate competitive pressure of one species on another, with - symbol representing negative effect on species at arrowhead, and - - or - - - indicating even greater negative effects. Firstly, species X could be released from competition with A, An. gambiae, following the impact of population suppression gene drive, which in turn could increase competition from species X on valued species Y. An additional possibility is that species Y could also be released from competition with An. gambiae which could act to increase the density of species Y. In that case, for the potential harm to occur the net effect of increased competition from species X with decreased competition from An. gambiae on species Y could still lead to the population of species Y being reduced