text: **Extended Data Fig. 1 | Collection of ancient genomes used in this study.**
  **a**, Ancient DNA samples included in this study (Supplementary Table 1). Samples 
  older than 3000 BCE are shown at 3000 BCE.**b**, Map showing mean coordinates 
  of groups in the Iron, Early Modern, and Viking Ages.**c**, Source groups used in 
  qpAdm modelling of Metal Age and early Medieval Europe (Figs. 2, 3 and 4), 
  showing sample ages. Sample sizes are shown in grey boxes.**d**,*F*ST between 
  Metal Age and early Medieval groups computed using popstats77 using options 
  --FST --informative. Sample sizes are shown in brackets and we show one 
  standard error. 