Analysis of medieval burials from Ibiza reveals genetic and pathogenic diversity during the Islamic period

AI interpretationAI-generated

Medieval Ibiza genomes reveal mixed ancestry and leprosy in Islamic times.

This study analyzed 13 individuals buried in an Islamic cemetery on Ibiza (950-1150 CE). Their DNA shows a mix of European, North African, and Sub-Saharan ancestries, reflecting migration and admixture after the Islamic conquest. North African gene flow occurred just 2-7 generations before they lived. Two individuals had Sub-Saharan origins from Senegambia and southern Chad, linking to trans-Saharan slave and military networks. Metagenomic analysis found pathogens, including one case of leprosy. The findings support a two-pulse settlement model: early conquest and later Almoravid influx.

• The community was genetically heterogeneous, with ancestry from Europe, North Africa, and Sub-Saharan Africa, indicating admixture after the Islamic conquest.
• North African gene flow happened only 2-7 generations before these individuals, suggesting recent migration and mixing, possibly on Ibiza itself.
• Two individuals traced Sub-Saharan ancestry to Senegambia and southern Chad, providing direct evidence of trans-Saharan connections via military and slave networks.
• Metagenomic analysis detected multiple pathogens, including Mycobacterium leprae in one individual, showing leprosy was present in medieval Ibiza.

Sample interpretation

Of 13 individuals, 9 had resolvable Y-chromosome lineages. The Y-haplogroups are diverse, including E-MZ8, E-CTS4236, R-KMS36, E-FT194594, E-M4732, R-BY44400, E-MZ1, and E-Z21392, each represented by one individual. Mitochondrial DNA shows H1e1a in two individuals, and J1c3, V1a, L3b2a, H1, K1b1a1 each in one. This genetic diversity mirrors the genome-wide heterogeneity, with both European and African lineages present. The sample size is small, so these frequencies are not representative of the whole population.

For genealogy enthusiasts

For ancestry enthusiasts, this study shows that medieval Islamic Iberia was a melting pot with recent African admixture. It highlights how ancient DNA can reveal individual stories of migration, including forced movements, and the health challenges like leprosy in past communities.