Extended Data Fig. 2: Projection PCA of Iron Age British and European genomes.

The bottom panel shows median positions of modern European populations (grey text with first three letters of country), Iron Age continental populations (black circles with first three letters of country) and Iron Age British and coastal French populations (coloured circles). Iron Age continental French genomes have been split into northern (nFr) and southern (sFr) populations. The map provides a colour key for British and coastal French Iron Age populations (Supplementary Table 12). Sites with data for more than one individual are shown as large circles with two letter identifiers. The median values for these multi-individual sites are plotted in the top PCA panel. The grey box delimits the area within two standard deviations of the mean value for the British Iron Age population along PC1 and PC2. Outlying individuals that fall beyond this area are plotted using their two-letter site ID. Two outliers from the current study are plotted using their full IDs (WBK02 and WBK30). Two data points from Urville-Nacqueville⁴¹ on the Normandy coast are also highlighted (brown). One of these (UN19) places further away from French populations, in agreement with SOURCEFIND results.