Farmer fidelity in the Canary Islands revealed by ancient DNA from prehistoric seeds

The Canary Islands were settled in the first millennium AD by colonizers likely originating from North Africa. The settlers developed a farming economy with barley as the main crop. Archaeological evidence suggests the islands then remained isolated until European sea-travellers discovered and colonized them during the 14th and 15th centuries. Here we report a population study of ancient DNA from twenty-one archaeobotanical barley grains from Gran Canaria dating from 1050 to 1440 cal AD. The material showed exceptional DNA preservation and genotyping was carried out for 99 single nucleotide markers. In addition 101 extant landrace accessions from the Canary Islands and the western Mediterranean were genotyped. The archaeological material showed high genetic similarity to extant landraces from the Canary Islands. In contrast, accessions from the Canary Islands were highly differentiated from both Iberian and North African mainland barley. Within the Canary Islands, landraces from the eas...