“…Similarly, disrupting a drug efflux pump can slow the adaptation of E. coli populations exposed to antibiotics by shifting them onto evolutionary paths where some mutations reduce the effect size of key resistance mutations (Lukačišinová et al, 2020). Nevertheless, both theoretical (Kryazhimskiy et al, 2009(Kryazhimskiy et al, , 2014Perfeito et al, 2014;Vaishnav et al, 2022) and smaller-scale studies in bacteria (Chou et al, 2011;Khan et al, 2011;MacLean et al, 2010;Wang et al, 2016), virus (Levy & Siegal, 2008;MacLean et al, 2010;Rokyta et al, 2011), yeast (Kryazhimskiy et al, 2014;Wei & Zhang, 2019) and multicellular fungi (Schoustra et al, 2016) support a strong role of diminishing return epistasis in adaptation. Our findings, precisely tracking the adaptation of a near complete genome-wide deletion collection, underscores that the power and generality of diminishing indeed are immense.…”