Figure 1. Geographic sampling. Locations of the 19 Arabian Peninsula sampling sites, including eight from the Red Sea, five from the Arabian Sea and the Sea of Oman, and six from the Persian/Arabian Gulf. Dark green shading represents the distribution of mangrove populations along the Arabian coasts, obtained from Spalding et al. (2010). Leaf tissue was collected from ten trees per sampling site for DNA extraction and whole genome sequencing. An eastern Australian population was also included as an outgroup (not shown).