Ancient DNA at the edge of the world: Continental immigration and the persistence of Neolithic male lineages in Bronze Age Orkney

Abstract

Orkney was a major cultural center during the Neolithic, 3800 to 2500 BC. Farming flourished, permanent stone settlements and chambered tombs were constructed, and long-range contacts were sustained. From ∼3200 BC, the number, density, and extravagance of settlements increased, and new ceremonial monuments and ceramic styles, possibly originating in Orkney, spread across Britain and Ireland. By ∼2800 BC, this phenomenon was waning, although Neolithic traditions persisted to at least 2500 BC. Unlike elsewhere in Britain, there is little material evidence to suggest a Beaker presence, suggesting that Orkney may have developed along an insular trajectory during the second millennium BC. We tested this by comparing new genomic evidence from 22 Bronze Age and 3 Iron Age burials in northwest Orkney with Neolithic burials from across the archipelago. We identified signals of inward migration on a scale unsuspected from the archaeological record: As elsewhere in Bronze Age Britain, much of the population displayed significant genome-wide ancestry deriving ultimately from the Pontic-Caspian Steppe. However, uniquely in northern and central Europe, most of the male lineages were inherited from the local Neolithic. This suggests that some male descendants of Neolithic Orkney may have remained distinct well into the Bronze Age, although there are signs that this had dwindled by the Iron Age. Furthermore, although the majority of mitochondrial DNA lineages evidently arrived afresh with the Bronze Age, we also find evidence for continuity in the female line of descent from Mesolithic Britain into the Bronze Age and even to the present day.

Ancient Maltese genomes and the genetic geography of Neolithic Europe

“…However, fineSTRUCTURE confirms the emerging distinctiveness of (SNP-captured) Orcadian individuals, as well as that of Basque Late Neolithic sites ( Figure 5 ), also captured in patterns of IBD sharing ( Figures 3 C and 4 ). An additional marker of separation is that Orkney islander ancient genomes have also recently been found to show unusual majority retention of male lineages across the Neolithic-Bronze Age transition, 72 a feature unique within Northern and Central Europe.…”

Migration and community in Bronze Age Orkney: innovation and continuity at the Links of Noltland

“…There is, however, also clear evidence for continuity from the Neolithic in the male line of descent (Dulias et al . 2022), suggesting that patrilocal marriage patterns persisted from the end of the Neolithic into the Bronze Age.…”

“…Ancient DNA analysis was undertaken on 25 samples of human petrous bone and teeth at the University of Huddersfield Ancient DNA Facility. Twenty-three of these were successfully sequenced (Dulias et al 2022) and yielded endogenous DNA content ranging between 3.1 and 66.5 per cent. Based on the genetic analysis, two infant samples from the multiple burial (which also had the same mitochondrial haplogroup and genetic sex) were identified as possibly being the same individual, and thus the minimum number of individuals analysed was 22.…”

“…This suggests a substantial replacement of the Orcadian population between the Late Neolithic and the Bronze Age, probably as a result of migration from the British mainland at some point during the 'Beaker' period. There is, however, also clear evidence for continuity from the Neolithic in the male line of descent (Dulias et al 2022), suggesting that patrilocal marriage patterns persisted from the end of the Neolithic into the Bronze Age.…”

“…Genetic analysis provides us with a tantalising glimpse into possible Bronze Age inheritance and marriage systems. The persistence of indigenous male lineages for at least 1000 years after the end of the Neolithic (Dulias et al 2022) may be associated with a system of patrilineal inheritance, in which household and land rights were passed down through the male line. Furthermore, that the number of households remained constant suggests that inherited 'assets' were not subdivided but remained intact through time.…”