Recent historical migration patterns across the North Sea

[cass]

Population-scale analysis of inheritance patterns across 858,635 individuals reveals recent historical migration patterns across the North Sea from the Middle Ages to the Industrial Revolution

full text
https://www.biorxiv.org/content/10.1101/2025.03.19.643007v1.full


supplementary-material
https://www.biorxiv.org/content/biorxiv/early/2025/03/19/2025.03.19.643007/DC1/embed/media-1.pdf?download=true



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It's interesting that the authors have detected Slavic-like admixture signal in Zealand and Funen.


https://i.ibb.co/r2ZZQBJP/Zrzut-ekranu-23-3-2025-143154.jpg (https://ibb.co/VYvvLF8y)

https://i.ibb.co/pBxwjgcz/Zrzut-ekranu-23-3-2025-143041.jpg (https://ibb.co/XrbLx91s)

https://i.ibb.co/yF3MKTBt/Zrzut-ekranu-23-3-2025-145427.jpg (https://ibb.co/k2drzn6j)

https://i.ibb.co/C5J45H2m/Zrzut-ekranu-23-3-2025-14520.jpg (https://ibb.co/PZTJZ6QF)

[J. Ketch]

It's curious that there's such a low IBD sharing in England with France, given the massive amount of 'France Iron Age' ancestry that came into England in the Middle Ages. Either that all came from a specific subgroup not sampled here, or it comes from the Benelux region, which has a much higher IBD sharing with England.

On the eastern and southern side of the North Sea, Britain has the highest sharing with the Netherlands (Figure 6). Derbyshire shows high IBD sharing with the Netherlands, Belgium and Germany for 2-4cM IBD (Figure S38-S40), as well Norway with England, following a geographic dispersal pattern at this IBD length stratification similar to that of Denmark (Figure S28). However, in contrast with Denmark, the Netherlands also has significant high IBD sharing with Kent in the South East of England consistently throughout time. Long IBD sharing with the Netherlands and Germany clearly shifts towards London and the surrounding areas along the South East coast of England (Figure S43). This aligns with what we have observed with Denmark. There are surprisingly low levels of average IBD sharing with France relative to other countries given its geographic location and entangled history. From the distribution of the mean IBD sharing between each French sample and all British samples (one vs all), we observed a long tail on the higher end, indicating that there could be subpopulations with higher sharing (Figure 6). Overall, samples from France predominantly show the high IBD sharing with London and other parts of South East England (Figure S41), with an increasing degree of sharing with London in recent generations (Figure S43)

[Grace O'Malley]

This is interesting and confirming other studies. I wish this was done for more European countries and hopefully it will be in the near future.


Indeed it is feasible to consider generating a comprehensive map of all European migrations from the medieval era onward by performing similar analyses across a pan-European modern cohort, and similarly for other continents and cross-continental migrations. From our study, we estimate that an even sampling of around 0.1% of the population (i.e. median sample size/median population size) would provide a resolution at the NUTS3 level of regionality in Europe. In addition, methodological improvements in integrating ancient genomes with modern ones would not only provide more support for specific migration patterns but also probably deepen the time resolution.

It also confirms what should be obvious as well that population distance does show close relationships and also that populations clustering together have more continuous gene flow.

[cass]

It is likely a matter of the significant transformation France underwent since the Celtic era. It should also be taken into account that the remaining reference populations are much smaller and more homogeneous. At one time, France was the most populous country in Europe and was clearly ethnographically divided into a northern and a southern part. I suspect that if the study had used only the population of Brittany, Hauts-de-France, and especially Normandy, the proportion of shared segments would have increased dramatically.