The IsoCAN project advances the largest dataset of radiocarbon datings linked to the early settling of the Canary Islands, as well as their critical evaluation through a chronometric hygiene protocol yielding rigorous Bayesian models. The findings of IsoCAN suggest that that (i) the Romans most likely discovered the islands around the 1st century AD and occupied the Islet of Lobos until the first half of the 2nd century AD; (ii) the Berbers from western North Africa set foot on Lanzarote somewhere between the 1st and 3rd centuries AD; (iii) the Romans and Berbers potentially cohabited the easternmost region of the archipelago; and (iv) the Berbers rapidly spread throughout the different islands over a period of 250 years resulting in what is identified as a Pan-Canarian cultural horizon.
The paleogenomic evidence gathered by IsoCAN confirms that the indigenous population of the Canary Islands have a North-African ancestry. The findings also suggest lack of gene flow between islands and constant or decreasing effective population sizes, suggesting that populations were isolated. While some island populations maintained relatively high genetic diversity, with the only detected bottleneck coinciding with the colonization time, other islands with fewer natural resources show the effects of insularity and isolation. Finally, consistent genetic differentiation between eastern and western islands points to a more complex colonization process than previously thought. Phylogenetic analysis of the goat mitochondrial DNA sequences indicates they belong to the A and A2a haplogroups, which are frequent in the Mediterranean Basin, coinciding with the results obtained from human populations. The paleogenomic evidence on plants has determined the millenium-long continual use of the same barley germplasm at some places in the Canary Islands.
The IsoCAN project has contributed to better understand how first settlers of the Canary Islands adapted their farming activities to the different natural conditions of each island. This project has reviewed the archaeobotanical evidence recorded in pre-Hispanic/Amazigh sites of the Canary Islands. Information obtained indicate the presence of a comparable crop ‘package’ on all the islands since at least the 3rd-5th centuries CE. This set of plants was likely introduced from north-western Africa, and consists of hulled barley, durum wheat, lentil, broad bean, pea, and fig. The crop ‘package’ was probably introduced at a single episode during the initial colonization, whereafter no more plants were added. After the initial settling and until the arrival of the European seafarers, the archipelago remained isolated. Over time, this led to a decline in crop diversity in all islands apart from Gran Canaria.
Finally, the analysis of the island palaeodietary profiles on humans allowed us to detect differences at inter-island and intra-island levels. The analyses of oral health conditions, stable isotope and dental microwear on humans present a complex portrait with significant variations. These differences were likely result of variations on subsistence practices and/or local adaptations to specific environments such as coastal areas. The findings suggest that each island culture developed a specific evolutionary path as result of different ecological constraints, diversity of crops, and social decisions.
