R-L21 or R1b1a2a1a2c, also known as R-M529 or R-S145, is a Human Y-chromosome DNA haplogroup. It is often linked to the Insular Celts.[1] One subclade, R-DF13 comprises over 99% of bearers. It is dominant among males in Ireland, Scotland, Wales and Brittany, present in high frequencies in England and western France and present also to a lesser extent in Iberia, Scandinavia and the Low Countries.[2]

Haplogroup R-L21
Distribution of major subclade R-DF13 across western Europe
Possible time of origin2,600 BC
Possible place of originSouth-west Britain
AncestorR1b (R-M343)
* R-M269
** R-L151
*** R-P312
**** R-Z290
DescendantsR-A5846
R-S552
* R-DF63
* R-DF13
Highest frequenciesIrish
Scottish
Welsh
Bretons
English

History edit

This haplogroup first emerges in the Early Bronze Age in Britain and Ireland, where the earliest samples begin to appear. Its introduction was part of a large genetic transformation associated with the Bell Beaker culture, wherein steppe descended peoples largely replaced Britain's earlier Neolithic population. The lineage reached a frequency of 90% in early Bronze Age Britain (being nearly absent in contemporary samples from the continent), it gradually declined through the Middle Bronze Age to 70% by the Iron Age (due to continental migrations which also increased the levels of EEF admixture among Britons).[note 1] It later fell to its modern levels in Britain after the Anglo-Saxon invasions. However, it still remains the dominant lineage in Ireland, Scotland, Brittany and Wales. Its origin is possibly around south west Britain as Cornwall is where the highest persistence of R-DF63 descended subclades are found, the sibling of the extremely dominant R-DF13 subclade.[note 2]

Archaeological testing edit

  • The body of a man excavated from Canada Farm, Sixpenny Handley, Dorset dating from 2468 to 2294 BC was found to be R-L21.[note 3]
  • The body of a man[note 4] found in Low Hauxley, Northumberland, dating from 2464 to 2209 BC, was classified as R1b1a1a2a1a2c1a1n (R-DF13 > R-Z39589 > R-FGC59881 > R-BY577 > R-BY575).[3]
  • 'Racton Man' found in Westbourne, West Sussex, England, dating from 2453 to 2146 BC and buried with a bronze dagger was classified as R-L21.[note 5]
  • The Companion[note 6] (dating to 2456‒2146 BC, aged 25–30), buried beside the Amesbury Archer[note 7] (dating to 2470‒2239 BC, aged 35–45), found near Stonehenge, belonged to R-L21. The archer (identified only as R-L151) may have been buried up to 80 years before the companion (although there is overlap in the dates) and was a kinsman (both shared a calcaneonavicular coalition on their feet), with a predicted relatedness coefficient of 0.0405 (95% confidence interval of -0.0161 to 0.0971). The isotopic profiles of the men indicate the archer spent the earliest years of his life in the Alps,[4] near modern Switzerland, and had higher levels of Neolithic ancestry compared to the companion who had spent his life in Britain but may have spent his early teens in North East Scotland or the Midlands.[5] The archer possessed above average EEF admixture of 45% whereas the companion had around 33%, more in line with other British samples of the Early Bronze Age. Another man,[note 8] also buried in Amesbury Down and dating from 2500 to 2100 BC was also R-L21[note 9] and is notable of having an EEF admixture of only 22%, the lowest ever found in Britain.[6]
  • A body of a man dating from around 2349-2135 BC found in Pollnagollum,[note 10] Ireland was classified as R-DF13 > R-FGC11134, a predominantly Irish subclade in modern populations and ancestral to the Eoghanact. Another body found in Treanmacmurtagh,[note 11] County Sligo, Ireland, dating from 2015 to 1758 BC was also classified as R-FGC11134.[7]
  • 'Ditchling Man', dating from 2287 to 2041 BC, found in Ditchling Road, Sussex and buried with a pottery beaker, arrowhead & shells. He was classified as R-Z290, the immediate parent of R-L21.[note 12]
  • Three Early Bronze Age men from burials on Rathlin Island off the north coast of Ireland were all R1b1a2a1a2c, or R-L21. Rathlin 1 dated from 2026 to 1885 BC and was defined as R-DF21. Rathlin 2 dated from 2024 to 1741 BC and was defined as further defined as R-DF13. Rathlin 3 dated from 1736 to 1534 BC and was defined as R-L21.[8]

Prominent members of R-L21 edit

Below are listed some theorized lineages of prominent families. Some of these relationships are confirmed by Y-DNA testing of verified descendants, but others are not. In particular, Fehér (2023) is poorly sourced, does not cite confirmatory testing for most identifications, and is highly suspect.

Notes edit

  1. ^ See Large-scale migration into Britain during the Middle to Late Bronze Age Figure 5
  2. ^ See Flood page 2
  3. ^ Sample ID: I5379, See Supplementary Tables, Large-scale migration into Britain during the Middle to Late Bronze Age
  4. ^ Sample ID: KD070
  5. ^ Sample ID: I27380, See Supplementary Tables, Large-scale migration into Britain during the Middle to Late Bronze Age
  6. ^ Sample ID: I2565
  7. ^ Sample ID: I14200
  8. ^ Sample ID: I2417
  9. ^ See Supplementary Tables, Large-scale migration into Britain during the Middle to Late Bronze Age
  10. ^ Study ID: Pollnagollum911
  11. ^ Study ID: Treanmacmurtagh116
  12. ^ Sample ID: I6774, See Supplementary Tables, Large-scale migration into Britain during the Middle to Late Bronze Age
  13. ^ See High Resolution Paternal Genetic History of Ireland... page 105

References edit

  1. ^ The phylogenealogy of R-L21:four and a half millennia of expansion and redistribution, Joe Flood Archive
  2. ^ Y-DNA Haplogroup R and its Subclades - 2018, International Society of Genetic Genealogy
  3. ^ Ancient DNA at the edge of the world: Continental immigration and the persistence of Neolithic male lineages in Bronze Age Orkney, Dulias et al., February 2022, Proceedings of the National Academy of Sciences 119(8):e2108001119, DOI:10.1073/pnas.2108001119, LicenseCC BY 4.0 Archive (ISOGG nomenclature)
  4. ^ The Amesbury Archer, Wessex Archaeology, accessed 20 Oct 2023Archive
  5. ^ Family ties: deciphering the DNA of the Amesbury Archer and the Companion, The Past, JANUARY 31, 2022, Archive
  6. ^ Large-scale migration into Britain during the Middle to Late Bronze Age, 22 Dec 2021, Nature volume 601, pages 588–594 (2022), Archive, Supplementary Information, Sections in supplementary material concering Amesbury Archer also reproduced on pg. 5 & 97
  7. ^ A Genomic Compendium of an Island - Documenting Continuity and Change across Irish Human Prehistory, Lara M. Cassidy, Smurfit Institute of Genetics, Trinity College Dublin, October 2017 Archive PDF
  8. ^ Cassidy, Lara M.; Martiniano, Rui; Murphy, Eileen M.; Teasdale, Matthew D.; Mallory, James; Hartwell, Barrie; Bradley, Daniel G. (2016). "Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome". Proceedings of the National Academy of Sciences. 113 (2): 368–373. Bibcode:2016PNAS..113..368C. doi:10.1073/pnas.1518445113. ISSN 0027-8424. PMC 4720318. PMID 26712024., Archive
  9. ^ PHYLOGENETIC ALIGNMENTS WITH GENEALOGIES OF DESCENT FROM AILILL ÓLOM, Nigel McCarthy, 2021Archive
  10. ^ O'Neill DNA Project, accessed 20 Oct 2023Archive
  11. ^ Sons of Aodh DNA Project, accessed 20 Oct 2023 Archive
  12. ^ High Resolution Paternal Genetic History of Ireland and its Implications for Demographic History, Tibor Feher, 2023, EMANIA — Bulletin of the Navan Research Group, No. 26, page 103 Archive
  13. ^ Forensic identification of skeletal remains from members of Ernesto Che Guevara's guerrillas in Bolivia based on DNA typing, February 2000International Journal of Legal Medicine 113(2):98-101, DOI:10.1007/PL00007716, Reference made to the identification in this paper

Further reading edit

External links edit