“…The extent of genomic diversity in AM fungi is a matter of considerable debate, which is beyond the scope of our paper (Lin et al, ; Maeda et al, ; Ropars & Corradi, ; Tisserant et al, ; Wyss et al, ). Our aim is to examine how, if diversity exists, it could plausibly be maintained (Bruns, Corradi, Redecker, Taylor, & Öpik, ; Sanders, ).…”