Biomolecular insights into North African-related ancestry, mobility and diet in eleventh-century Al-Andalus

Abstract

Historical records document medieval immigration from North Africa to Iberia to create Islamic al-Andalus. Here, we present a low-coverage genome of an eleventh century CE man buried in an Islamic necropolis in Segorbe, near Valencia, Spain. Uniparental lineages indicate North African ancestry, but at the autosomal level he displays a mosaic of North African and European-like ancestries, distinct from any present-day population. Altogether, the genome-wide evidence, stable isotope results and the age of the burial indicate that his ancestry was ultimately a result of admixture between recently arrived Amazigh people (Berbers) and the population inhabiting the Peninsula prior to the Islamic conquest. We detect differences between our sample and a previously published group of contemporary individuals from Valencia, exemplifying how detailed, small-scale aDNA studies can illuminate fine-grained regional and temporal differences. His genome demonstrates how ancient DNA studies can capture portraits of past genetic variation that have been erased by later demographic shifts—in this case, most likely the seventeenth century CE expulsion of formerly Islamic communities as tolerance dissipated following the Reconquista by the Catholic kingdoms of the north.

Helena’s Many Daughters: More Mitogenome Diversity behind the Most Common West Eurasian mtDNA Control Region Haplotype in an Extended Italian Population Sample

“…Several of the shared polymorphism patterns were reported before, intriguingly being mostly from Italy [ 39 , 40 , 41 , 42 ] but also Spain [ 43 ]. The yet unnamed clusters were H-930A-3531A-4703C ( n = 3 in this study), H1-15217A ( n = 7, also in [ 39 ]), H1-709A-15470C ( n = 4), H1-14329T ( n = 4, also in [ 39 , 40 , 41 ]), H1e1-11914A-13938T-15930A ( n = 2, also in [ 39 ]), H1q3-@16037-11266T ( n = 2, also in [ 42 ]), H3-6827C ( n = 4, also in [ 39 , 43 ]), H3-7664A-8406T ( n = 2), and H3-11200G-(2851G) ( n = 3, also in [ 39 , 40 ]) ( Table S1, Figure S1 ). Additional unpublished and/or geographically unassigned related mitogenomes are collected in online resources [ 44 , 45 ].…”

Phylogeography of Sub-Saharan Mitochondrial Lineages Outside Africa Highlights the Roles of the Holocene Climate Changes and the Atlantic Slave Trade

“…However, some small bumps at about 1.0 ka most likely represent arrivals with the Atlantic slave trade, possibly conflated with a few earlier minor movements in the case of Europe, and probably artificially inflated due to the presence of a small number of sequencing artefacts, which would have a disproportionate impact at this timescale. It is also possible that the mutation rate correction for purifying selection [ 47 ] at this very recent time depth is insufficient. Given the high number of founders detected in North America, it is even possible that this number is still underestimated since while the main lineages were detected, some of the variation within those lineages might have already been carried to North America, therefore slightly increasing the estimated founder ages.…”

“…We classified samples into haplogroups using Haplogrep 2 [ 57 ] and grouped them into major subclades L0, L1, L2, L3, L4, L5, and L6 for phylogenetic analysis. We performed phylogenetic reconstruction using the Network software, using the reduced-median algorithm [ 58 ] and weighting mtDNA sequence positions according to their relative frequency [ 47 ], guided by the tree structure provided by PhyloTree [ 59 ]. We calculated age estimates of all tree nodes using rho and the time-dependent molecular clock established by Soares et al [ 47 ].…”

“…We calculated standard errors according to Saillard et al [ 63 ], allowing the estimation of realistic errors in the Bayesian partitioning, as introduced before in the methodology [ 16 ]. We used a mutation rate of 1 substitution per 2565 years, this being the estimated time-dependent mutation rate close to the present, allowing for purifying selection [ 47 ]. The mutation rate following the correction curve over this interval changes by less than 7%, which should not affect the results in any significant way.…”

Founder lineages in the Iberian Roma mitogenomes recapitulate the Roma diaspora and show the effects of demographic bottlenecks

“…In order to compare the relevance of these founder lineages within the Iberian Roma, we repeated the analysis in a dataset of over 1,000 non-Roma Spanish sequences 43 , 44 . First, the whole non-Roma Spanish reference dataset was analyzed looking for haplogroups reaching a relative frequency of 0.0278, which is the value corresponding to the threshold set for the Roma (4/144, where 144 is the Roma sample size).…”