Author Correction: The spread of steppe and Iranian-related ancestry in the islands of the western Mediterranean.

D.M.F. was supported by an Irish Research Council grant GOIPG/2013/36. Radiocarbon work was supported in part by the NSF Archaeometry program BCS-1460369 (to D.J.K. and B.J.C). C.L.-F. was supported by Obra Social La Caixa and by FEDER-MINECO (BFU2015-64699-P and PGC2018-095931-B-100). D.C. was supported by grant 20177PJ9XF MIUR PRIN 2017. D.Reich is an Investigator of the Howard Hughes Medical Institute, and his ancient-DNA laboratory work was supported by National Science Foundation HOMINID grant BCS-1032255, a National Institutes of Health grant GM100233, an Allen Discovery Center grant, and grant no. 61220 from the John Templeton Foundation.