Genomic Analyses of Pre-European Conquest Human Remains from the Canary Islands Reveal Close Affinity to Modern North Africans

Abstract

The origins and genetic affinity of the aboriginal inhabitants of the Canary Islands, commonly known as Guanches, are poorly understood. Though radiocarbon dates on archaeological remains such as charcoal, seeds, and domestic animal bones suggest that people have inhabited the islands since the 5 century BCE [1-3], it remains unclear how many times, and by whom, the islands were first settled [4, 5]. Previously published ancient DNA analyses of uniparental genetic markers have shown that the Guanches carried common North African Y chromosome markers (E-M81, E-M78, and J-M267) and mitochondrial lineages such as U6b, in addition to common Eurasian haplogroups [6-8]. These results are in agreement with some linguistic, archaeological, and anthropological data indicating an origin from a North African Berber-like population [1, 4, 9]. However, to date there are no published Guanche autosomal genomes to help elucidate and directly test this hypothesis. To resolve this, we generated the first genome-wide sequence data and mitochondrial genomes from eleven archaeological Guanche individuals originating from Gran Canaria and Tenerife. Five of the individuals (directly radiocarbon dated to a time transect spanning the 7-11 centuries CE) yielded sufficient autosomal genome coverage (0.21× to 3.93×) for population genomic analysis. Our results show that the Guanches were genetically similar over time and that they display the greatest genetic affinity to extant Northwest Africans, strongly supporting the hypothesis of a Berber-like origin. We also estimate that the Guanches have contributed 16%-31% autosomal ancestry to modern Canary Islanders, here represented by two individuals from Gran Canaria.

Ancient genomes from North Africa evidence prehistoric migrations to the Maghreb from both the Levant and Europe

“…IAM samples belong to the mtDNA haplogroups U6a and M1—both of which are associated with the back migration to Africa from Eurasia in Upper Palaeolithic times 18,19 —while KEB samples belong to haplogroups K1, T2 and X2, prominently found in Anatolian and European Neolithic samples 2,20 (Supplementary Note 4). Regarding the paternal lineages, IAM individuals carry Y chromosomes distantly related to the typically North African E-M81 haplogroup, while the Y chromosome from KEB belongs to the T-M184 haplogroup; though scarce and broadly distributed today, this haplogroup has also been observed in European Neolithic individuals 16 (Supplementary Note 5). Both mtDNA and Y-chromosome lineages (K1, J2 and T2 haplogroups, and G-M201 haplogroup, respectively) for samples from TOR (Iberian Early Neolithic) are similar to those observed in Europe during Neolithic times 20 .…”

“…Southern Iberian Neolithic individuals from TOR cluster with Sardinians and with other Anatolian and European Neolithic samples. Moreover, KEB samples are placed halfway between the IAM and Anatolian/European farmer clusters, in close proximity to Levant aDNA samples and also to Guanche samples 16 , the indigenous population of the Canary Islands known to have a Berber origin 22 . When compared using ADMIXTURE (See Supplementary Note 7 for details), IAM samples possess ∼100% of a component partially shared by aDNA samples from the Middle East and Levant at low K values.…”

“…Genetic data from present-day populations 11-13 suggests that North African ancestry has contributions from four main sources: 1) an autochthonous Maghrebi component related to a back migration to Africa ∼12,000 years ago from Eurasia; 2) a Middle Eastern component probably associated with the Arab conquest; 3) a sub-Saharan component derived from trans-Saharan migrations; and 4) a European component that has been linked to recent historic movements. Paleogenomic studies have begun to provide insights into North African Prehistory 14-16 ; however, no research to date has tested whether the Neolithic transition in the Maghreb was driven by local populations who adopted cultural and technological innovations or the migration of people. Here, we perform genome-wide analysis of remains from the Early Neolithic site of Ifri n’Amr or Moussa (IAM; ∼5,200 BCE, n=7) and the Late Neolithic site of Kelif el Boroud (KEB; ∼3,000 BCE; n=8) (Supplementary Note 1).…”

Exploring the risks accompanying child-bearing in aboriginal society on Gran Canaria (Canary Islands, 13th–15th cal. CE): death of a pregnant woman during her third trimester

“…1). The ancient inhabitants of Gran Canaria came from North Africa, probably settling on the island sometime during the first centuries of the present era (Arco-Aguilar et al 2017;Atoche-Peña & Ramírez-Rodríguez 2011;Morales et al 2017), as genetic and linguistic evidence along with material culture suggest (Maca-Meyer et al 2004;Tejera-Gaspar et al 2006;Rodríguez-Varela et al 2017). Archaeological studies, along with ethnohistorical sources arising from contact with Europeans, portray the ancient canaries as a stratified society (Velasco-Vázquez 1999;Onrubia-Pintado 2003;Santana-Cabrera et al 2015).…”

Boots on the ground in Africa's ancient DNA ‘revolution’: archaeological perspectives on ethics and best practices

“…In recent years, the pace of human ancient DNA (aDNA) research in Africa has accelerated, from studies of single individuals to analyses of larger groups with wider analytical scope (Morris et al 2014;Gallego Llorente et al 2015;Rodríguez-Varela et al 2017;Schlebusch et al 2017;Schuenemann et al 2017;Skoglund et al 2017). Human aDNA from African contexts is globally exceptional in that it holds the potential to address deep-time questions on our species' origins.…”