A Transient Pulse of Genetic Admixture from the Crusaders in the Near East Identified from Ancient Genome Sequences

Marc Haber,Claude Doumet-Serhal,Christiana L Scheib,Yali Xue,Richard Mikulski,Rui Martiniano,Bettina Fischer-Genz,Holger Schutkowski,Toomas Kivisild,Chris Tyler-Smith

doi:10.1016/j.ajhg.2019.03.015

Abstract

During the medieval period, hundreds of thousands of Europeans migrated to the Near East to take part in the Crusades, and many of them settled in the newly established Christian states along the Eastern Mediterranean coast. Here, we present a genetic snapshot of these events and their aftermath by sequencing the whole genomes of 13 individuals who lived in what is today known as Lebanon between the 3rd and 13th centuries CE. These include nine individuals from the “Crusaders’ pit” in Sidon, a mass burial in South Lebanon identified from the archaeology as the grave of Crusaders killed during a battle in the 13th century CE. We show that all of the Crusaders’ pit individuals were males; some were Western Europeans from diverse origins, some were locals (genetically indistinguishable from present-day Lebanese), and two individuals were a mixture of European and Near Eastern ancestries, providing direct evidence that the Crusaders admixed with the local population. However, these mixtures appear to have had limited genetic consequences since signals of admixture with Europeans are not significant in any Lebanese group today—in particular, Lebanese Christians are today genetically similar to local people who lived during the Roman period which preceded the Crusades by more than four centuries.

Highlights

Human migrations, which often accompanied historical battles and invasions, have profoundly reshaped the genetic diversity of local populations in many regions
We sampled the petrous portion of the temporal bones from 16 of these individuals and, sampled five local individuals from an archaeological excavation in Qornet ed-Deir, Jabal Moussa UNESCO Biosphere Reserve in Mount Lebanon (Figure S3),[10] who lived during the Roman period (237–632 calCE), and these would represent the local ancestry before the time of the Crusades
Two individuals appeared to have an intermediate position between Europeans and Near Easterners: individual SI-41 overlapped with Neolithic Anatolians on the principal component analysis (PCA) and was distant from any modern West Eurasian population, and individual SI-53 overlapped with Ashkenazi Jews and South Italians

Summary

Introduction

Human migrations, which often accompanied historical battles and invasions, have profoundly reshaped the genetic diversity of local populations in many regions. More recently, using whole-genome sequences from modern and ancient individuals, we found that present-day Lebanese derive most of their genetic ancestry from the local Bronze Age population and from a Eurasian Stepperelated admixture which occurred around 1,750–170 BCE.[6] the Lebanese autosomal genomes appear not to have been impacted by the Crusades.

Results

Conclusion