Acknowledgements
The authors would like to thank Neal Cantin and the GBRLegacy team for their help in collecting the Acropora spathulata colonies from the far north, and the coral collection teams from SeaSim at AIMS for collecting coral colonies from the central reef. Corals were collected under permits G16/38488.1 and G12/35236.1. We would also like to thank Dylan Skilton, Siobhan Threlfall, Magena Marzonie, Hanaka Mera, and Justin Speaks, and Carly Randall for their help with coral spawning, juvenile photographs, and measurements, and Alyx Terrell for her help in larval DNA extractions. We would like to acknowledge support from the Australian Institute of Marine science and the Australian Research Council Laureate Fellowship FL180100036 to M.J.H.v.O.