B A Figure 1 Supplementary Figure S1: World map showing sampling and reference sites. (A) Location of study sites in the Canadian High Arctic, alpine and Antarctic sites containing taxa with highest similarity matches to the High Arctic sequences. (B) Detailed map showing the sampling locations along the northern coastline of Ellesmere Island, Canadian High Arctic. B Northern Ellesmere Island 1. Markham Ice Shelf 2. Ward Hunt Lake & Quttinirpaaq Lagoon 3. Ward Hunt Ice Shelf 4. Lake A & Antoniades Pond 3 2 1 83°N 4 Ellesmere Island, High Arctic, Canada 75°W 72°W Tian Shan Mtns, China Larsemann & Vestfold Hills, Antarctica McMurdo Ice Shelf & Dry Valleys, Antarctica A