Post by Admin on Mar 10, 2023 18:33:38 GMT
Discussion
Combined, the genetic results and AMS dates from these individuals indicate the presence of two genetically distinct groups in Britain in the Late Glacial period. This is evident through both the differential mitochondrial haplogroups of the two individuals analysed here and also through their distinctive ancestral patterns. The Gough’s Cave individual shows clear affinity to Goyet Q2 ancestry, whereas the Kendrick’s Cave individual shows affinity to Villabruna (WHG). It is also interesting to note the lack of genetic admixture at Gough’s Cave given the lithics assemblage is of mixed origin, containing both late Magdalenian and early Federmesser-Gruppen technologies. Furthermore, the single culturally identifiable lithic from Kendrick’s Cave has been ascribed to the Magdalenian, whereas Villabruna ancestry has previously been associated with Epigravettian and Azilian/Federmesser cultures. However, the incised and perforated artefacts at Kendrick’s Cave do bear stylistic similarities with continental art linked to the Federmesser-Gruppen culture38. It may be that boundaries between cultural and genetic affinities break down at this time or alternatively culturally and genetically distinct groups are present at both Gough’s Cave and Kendrick’s Cave but the evidence is at a resolution we at present cannot chronologically resolve. However, our analyses demonstrate that Villabruna ancestry was already present within Britain during the Late Glacial. This suggests that the emergence of Villabruna ancestry in Britain predates the Holocene. It is possible that there may have been more than one migration of Villabruna ancestry into Britain however—perhaps, for example, a secondary migration at the start of the Mesolithic period—but our data do not currently have the resolution to comment on this possibility.
It is important to note, however, that the temperate climate of the Late Glacial Interstadial and the early Holocene was punctuated by the Younger Dryas Stadial (~12,900–11,700 BP, broadly equivalent to GS-1), when temperatures were notably colder, ice sheets expanded in Scotland and reindeer once again became the dominant fauna in the cave sites of southwest Britain. Currently, there are no radiocarbon determinations documenting human presence in the British Isles during the Younger Dryas52. Although this may be the result of taphonomy and preservation issues, if a gap in human presence is real then this indicates more than one migration of Villabruna ancestry into Britain may have occurred. On the basis of the data currently available, whilst the Late Palaeolithic Kendrick’s Cave individual indicates it has single-source Villabruna ancestry, some British Mesolithic individuals show significantly more affinity to Cheddar Man, which can be modelled as having two-source Goyet Q2 and Villabruna ancestry (Supplementary Information). This, therefore, suggests that a degree of genetic change may have occurred in tandem with the substantial cultural change seen with the emergence of the Mesolithic in Britain, to the limits of our current resolution.
Interestingly, these two genetically distinct Late Upper Palaeolithic populations, present in Britain ~600 and 1,200 years apart, appear to have also had isotopically different diets. The individuals from Kendrick’s Cave show evidence of intensive consumption of marine and freshwater foods, including high trophic level marine mammals30,40,53. In contrast, the Gough’s Cave human skeletal assemblage shows no evidence for marine or freshwater resource consumption and instead diet was based primarily on terrestrial herbivores, specifically red deer and bovids but also horses28,54. However, this assumes that the cannibalized individuals were also those consuming the faunal remains recovered from the site. In tandem with this, it is interesting to note that whilst there is evidence of cannibalism and secondary treatment of human material at Gough’s Cave (also found at other Magdalenian sites such as Brillenhöhle and Höhle Fels in Germany and Mazsycka Cave in Poland55,56), Kendrick’s Cave has been interpreted as being used as a possible burial site, associated with important portable art items such as the decorated horse mandible57. Combined, these lines of evidence support the interpretation that at least two different human groups, with different genetic affinities and dietary and cultural behaviours, were present in Britain during the Late Glacial.
Determining potential sources for these populations is, however, complex. During this period, Britain was connected via Doggerland to the main European continent. Despite this, the Late Glacial Channel River was probably difficult to cross at its more southwesterly points, such as from the Paris Basin and is suggested to have created (seasonal) barriers to movement58,59. Instead, it has been proposed that populations arriving in Britain during the Late Glacial may have taken a more easterly route, between the Channel River and the Palaeo-Elbe catchment, possibly across an area of higher ground linking Britain with Belgium and the Netherlands59,60,61. These hypotheses are difficult to test, however, due to the lack of Late Palaeolithic remains suitable for aDNA and AMS dating preserved in these regions.
Nonetheless, our qpAdm modelling indicates that Goyet Q2 ancestry persisted in Britain until at least 15,070 cal. BP and potentially as late as 14,610 cal. BP based on the modelled boundary start and end dates for Gough’s Cave. The appearance of people in southwest England before the Interstadial warming and soon after the earliest evidence for reindeer and horse returned to the landscape, combined with this Goyet Q2 ancestry, suggests that these people may have come from Magdalenian populations that had remained isolated during the LGM and early Late Glacial from more southerly populations where admixed Goyet Q2 and Villabruna ancestry is evident8. Indeed, it is perhaps the post-LGM climate amelioration and Late Glacial rapid climatic warming, causing key cold-adapted prey species to contract to more northerly latitudes, which facilitated this—in effect, a retreat to the north by Magdalenian cold-adapted populations. From at least 13,800 to 13,240 cal. BP (Kendricks_074, 95% confidence, OxA-17089) however, Villabruna (WHG) ancestry appears in Britain and persists into the Mesolithic, being replaced only at the start of the Neolithic with the emergence of agriculture. The source population for this ancestry and its route into Britain remains unclear but the rapid climatic warming of the Late Glacial Interstadial, which resulted in substantial environmental change, may have provided new ecological opportunities for human populations. Similarly, these environmental developments may have placed considerable pressures on cold-adapted fauna and on the people who specialized in their exploitation.
Conclusions
We extend the scope of European palaeogenomics here by sequencing the first Palaeolithic human skeletal material from Britain. Furthermore, the genetic data generated within this study clearly demonstrate that there appears to have been dual genetic ancestries present in Britain during the Late Glacial period. New AMS dating and recalibration of existing dates generated on material from the two sites studied here also indicate that these two genetically distinct populations in Late Upper Palaeolithic Britain were close in date, potentially ~600 years apart. Interestingly, dual Late Pleistocene genetic ancestry has also been demonstrated in Iberian hunter gatherers9. However, although admixed Goyet Q2 and Villabruna ancestry can be seen in southern Europe at El Mirón from at least ~18,770 cal. BP (ref. 8; Fig. 1), this signature of admixture is not visible in British individuals, thereby suggesting a more significant genetic turnover or replacement in northwestern Europe than in the southwest.
In addition, we demonstrate that the Gough’s Cave and Kendrick’s Cave individuals, despite being close in date, differ not only in their genetic ancestry profiles but also in their mortuary practices and their diets, as evidenced through stable isotopic analyses. This presents a picture of a dynamic and varied Late Glacial period within Britain, with changes occurring in the Late Upper Palaeolithic in diet, funerary behaviours, technologies and genetic affinity at a time of rapid environmental and ecological change. With the addition of our data to the existing knowledge of early prehistoric genetics in Britain24,25, the emerging scenario is one of multiple genetic population turnover events in the United Kingdom. This can be seen to reflect a dynamic, changing population throughout British early prehistory and which mirrors the events seen across continental Europe.
The lack of human remains from Late Pleistocene Britain, combined with DNA preservational limits, means analyses of the period will always be limited. We demonstrate here, however, that it is possible to obtain useful genetic information from Late Glacial human skeletal material in Britain and that these data can further our understandings of early occupation of the British Isles, population movement, interactions with the continental Europe and potential population replacements.
Combined, the genetic results and AMS dates from these individuals indicate the presence of two genetically distinct groups in Britain in the Late Glacial period. This is evident through both the differential mitochondrial haplogroups of the two individuals analysed here and also through their distinctive ancestral patterns. The Gough’s Cave individual shows clear affinity to Goyet Q2 ancestry, whereas the Kendrick’s Cave individual shows affinity to Villabruna (WHG). It is also interesting to note the lack of genetic admixture at Gough’s Cave given the lithics assemblage is of mixed origin, containing both late Magdalenian and early Federmesser-Gruppen technologies. Furthermore, the single culturally identifiable lithic from Kendrick’s Cave has been ascribed to the Magdalenian, whereas Villabruna ancestry has previously been associated with Epigravettian and Azilian/Federmesser cultures. However, the incised and perforated artefacts at Kendrick’s Cave do bear stylistic similarities with continental art linked to the Federmesser-Gruppen culture38. It may be that boundaries between cultural and genetic affinities break down at this time or alternatively culturally and genetically distinct groups are present at both Gough’s Cave and Kendrick’s Cave but the evidence is at a resolution we at present cannot chronologically resolve. However, our analyses demonstrate that Villabruna ancestry was already present within Britain during the Late Glacial. This suggests that the emergence of Villabruna ancestry in Britain predates the Holocene. It is possible that there may have been more than one migration of Villabruna ancestry into Britain however—perhaps, for example, a secondary migration at the start of the Mesolithic period—but our data do not currently have the resolution to comment on this possibility.
It is important to note, however, that the temperate climate of the Late Glacial Interstadial and the early Holocene was punctuated by the Younger Dryas Stadial (~12,900–11,700 BP, broadly equivalent to GS-1), when temperatures were notably colder, ice sheets expanded in Scotland and reindeer once again became the dominant fauna in the cave sites of southwest Britain. Currently, there are no radiocarbon determinations documenting human presence in the British Isles during the Younger Dryas52. Although this may be the result of taphonomy and preservation issues, if a gap in human presence is real then this indicates more than one migration of Villabruna ancestry into Britain may have occurred. On the basis of the data currently available, whilst the Late Palaeolithic Kendrick’s Cave individual indicates it has single-source Villabruna ancestry, some British Mesolithic individuals show significantly more affinity to Cheddar Man, which can be modelled as having two-source Goyet Q2 and Villabruna ancestry (Supplementary Information). This, therefore, suggests that a degree of genetic change may have occurred in tandem with the substantial cultural change seen with the emergence of the Mesolithic in Britain, to the limits of our current resolution.
Interestingly, these two genetically distinct Late Upper Palaeolithic populations, present in Britain ~600 and 1,200 years apart, appear to have also had isotopically different diets. The individuals from Kendrick’s Cave show evidence of intensive consumption of marine and freshwater foods, including high trophic level marine mammals30,40,53. In contrast, the Gough’s Cave human skeletal assemblage shows no evidence for marine or freshwater resource consumption and instead diet was based primarily on terrestrial herbivores, specifically red deer and bovids but also horses28,54. However, this assumes that the cannibalized individuals were also those consuming the faunal remains recovered from the site. In tandem with this, it is interesting to note that whilst there is evidence of cannibalism and secondary treatment of human material at Gough’s Cave (also found at other Magdalenian sites such as Brillenhöhle and Höhle Fels in Germany and Mazsycka Cave in Poland55,56), Kendrick’s Cave has been interpreted as being used as a possible burial site, associated with important portable art items such as the decorated horse mandible57. Combined, these lines of evidence support the interpretation that at least two different human groups, with different genetic affinities and dietary and cultural behaviours, were present in Britain during the Late Glacial.
Determining potential sources for these populations is, however, complex. During this period, Britain was connected via Doggerland to the main European continent. Despite this, the Late Glacial Channel River was probably difficult to cross at its more southwesterly points, such as from the Paris Basin and is suggested to have created (seasonal) barriers to movement58,59. Instead, it has been proposed that populations arriving in Britain during the Late Glacial may have taken a more easterly route, between the Channel River and the Palaeo-Elbe catchment, possibly across an area of higher ground linking Britain with Belgium and the Netherlands59,60,61. These hypotheses are difficult to test, however, due to the lack of Late Palaeolithic remains suitable for aDNA and AMS dating preserved in these regions.
Nonetheless, our qpAdm modelling indicates that Goyet Q2 ancestry persisted in Britain until at least 15,070 cal. BP and potentially as late as 14,610 cal. BP based on the modelled boundary start and end dates for Gough’s Cave. The appearance of people in southwest England before the Interstadial warming and soon after the earliest evidence for reindeer and horse returned to the landscape, combined with this Goyet Q2 ancestry, suggests that these people may have come from Magdalenian populations that had remained isolated during the LGM and early Late Glacial from more southerly populations where admixed Goyet Q2 and Villabruna ancestry is evident8. Indeed, it is perhaps the post-LGM climate amelioration and Late Glacial rapid climatic warming, causing key cold-adapted prey species to contract to more northerly latitudes, which facilitated this—in effect, a retreat to the north by Magdalenian cold-adapted populations. From at least 13,800 to 13,240 cal. BP (Kendricks_074, 95% confidence, OxA-17089) however, Villabruna (WHG) ancestry appears in Britain and persists into the Mesolithic, being replaced only at the start of the Neolithic with the emergence of agriculture. The source population for this ancestry and its route into Britain remains unclear but the rapid climatic warming of the Late Glacial Interstadial, which resulted in substantial environmental change, may have provided new ecological opportunities for human populations. Similarly, these environmental developments may have placed considerable pressures on cold-adapted fauna and on the people who specialized in their exploitation.
Conclusions
We extend the scope of European palaeogenomics here by sequencing the first Palaeolithic human skeletal material from Britain. Furthermore, the genetic data generated within this study clearly demonstrate that there appears to have been dual genetic ancestries present in Britain during the Late Glacial period. New AMS dating and recalibration of existing dates generated on material from the two sites studied here also indicate that these two genetically distinct populations in Late Upper Palaeolithic Britain were close in date, potentially ~600 years apart. Interestingly, dual Late Pleistocene genetic ancestry has also been demonstrated in Iberian hunter gatherers9. However, although admixed Goyet Q2 and Villabruna ancestry can be seen in southern Europe at El Mirón from at least ~18,770 cal. BP (ref. 8; Fig. 1), this signature of admixture is not visible in British individuals, thereby suggesting a more significant genetic turnover or replacement in northwestern Europe than in the southwest.
In addition, we demonstrate that the Gough’s Cave and Kendrick’s Cave individuals, despite being close in date, differ not only in their genetic ancestry profiles but also in their mortuary practices and their diets, as evidenced through stable isotopic analyses. This presents a picture of a dynamic and varied Late Glacial period within Britain, with changes occurring in the Late Upper Palaeolithic in diet, funerary behaviours, technologies and genetic affinity at a time of rapid environmental and ecological change. With the addition of our data to the existing knowledge of early prehistoric genetics in Britain24,25, the emerging scenario is one of multiple genetic population turnover events in the United Kingdom. This can be seen to reflect a dynamic, changing population throughout British early prehistory and which mirrors the events seen across continental Europe.
The lack of human remains from Late Pleistocene Britain, combined with DNA preservational limits, means analyses of the period will always be limited. We demonstrate here, however, that it is possible to obtain useful genetic information from Late Glacial human skeletal material in Britain and that these data can further our understandings of early occupation of the British Isles, population movement, interactions with the continental Europe and potential population replacements.