Extended Data Fig. 1: Post-MBA Britain was not a mix of earlier British populations.
From: Large-scale migration into Britain during the Middle to Late Bronze Age
a, qpAdm p-values for modelling British groups as a mix of Neolithic and Chalcolithic/EBA populations from England and Wales or Scotland (outgroups OldAfrica, OldSteppe, Turkey_N, CzechRepublic.Slovakia.Germany_3800.to.2700BP, Netherlands_C.EBA, Poland_Globular_Amphora, Spain.Portugal_4425.to.3800BP, CzechRepublic.Slovakia.Germany_4465.to.3800.BP, Sardinia_4100.to.2700BP, Sardinia_8100.to.4100BP, Spain.Portugal_6500.to.4425BP). We highlight p<0.05 (yellow) or p<0.005 (red). Both sources and target populations in this analysis remove outlier individuals (“Filter 2” in Supplementary Table 5); we obtain qualitatively similar results when outlier individuals are not removed (not shown). b, To obtain insight into the source of the new ancestry in Britain in the IA, we computed f4(England.and.Wales_IA, α(England.and.Wales_N) + (1-α)(England.Wales_C.EBA); R1, R2) for different (R1, R2) population pairs. If England.and.Wales_IA is a simple mixture of England.and.Wales_N and England.and.Wales_C.EBA without additional ancestry, then for some mixture proportion the statistic will be consistent with zero for all (R1, R2 pairs). When (R1, R2) = (OldAfrica, OldSteppe) feasible Z-scores (Z1 in the plot) are observed when α∼0.85, showing that ~85% ancestry from England.and.Wales_C.EBA ancestry is needed to contribute the observed proportion of Steppe ancestry in England.and.Wales_IA. However, when (R1, R2) is (Balkan_N, Sardinian_8100.to.4100BP), we get infeasible Z-scores (Z2) of <−6 across the range where Z1 is remotely feasible. Thus, Iron Age people from England and Wales must have ancestry from an additional population deeply related to Sardinian Early Neolithic groups.
