Kendra Scheer led this study, with Luane Landau, Charikleia Karageorgiou and colleagues, and with Tom Brutsaert, Abigail Bigham and collaborators in Peru. Indigenous Andean populations carry unusually high amylase (AMY1) copy numbers, and the increase appears to have happened rapidly — consistent with adaptation to a starch-rich, potato-based diet. It is a recent chapter in the same stretch of the genome our earlier reconstruction of the amylase locus described.