Uncovering genetic signatures of the Walser migration in the Alps: Patterns of diversity and differentiation

[kingdavid]

Abstract​

Since leaving Africa, human populations have gone through a series of range expansions. While the genomic signatures of these expansions are well detectable on a continental scale, the genomic consequences of small-scale expansions over shorter time spans are more challenging to disentangle. The medieval migration of the Walser people from their homeland in southern Switzerland (Upper Valais) into other regions of the Alps is a good example of such a comparatively recent geographic and demographic expansion in humans. While several studies from the 1980s, based on allozyme markers, assessed levels of isolation and inbreeding in individual Walser communities, they mostly did so by focusing on a single community at a time. Here, we provide a comprehensive overview of genetic diversity and differentiation based on samples from multiple Walser, Walser-homeland, and non-Walser Alpine communities, along with an idealized (simulated) Swiss reference population (Ref-Pop). To explore genetic signals of the Walser migration in the genomes of their descendants, we use a set of forensic autosomal STRs as well as uniparental markers. Estimates of pairwise FST based on autosomal STRs reveal that the Walser-homeland and Walser communities show low to moderate genetic differentiation from the non-Walser Alpine communities and the idealized Ref-Pop. The geographically more remote and likely more isolated Walser-homeland community of Lötschental and the Walser communities of Vals and Gressoney appear genetically more strongly differentiated than other communities. Analyses of mitochondrial DNA revealed the presence of haplogroup W6 among the Walser communities, a haplogroup that is otherwise rare in central Europe. Our study contributes to the understanding of genetic diversity in the Walser-homeland and Walser people, but also highlights the need for a more comprehensive study of the population genetic structure and evolutionary history of European Alpine populations using genome-wide data.

source:

https://www.sciencedirect.com/science/article/pii/S1872497324002023#tbl0020

p.s
interesting to see e1b1a-m2 case
14029 -Furna -e1b1a-e-v38>m4231
there is got to be some earlier migration
who could explain e1b1a-m2 downstream in alps region
maybe during roman period as some kind of soldiers

 

[Maciamo]

How can there still be undetermined haplogroups in 2024? Why are they still using outdated STRs instead of SNPs? Rather surprising from the University of Zurich.

 

[kingdavid]

How can there still be undetermined haplogroups in 2024? Why are they still using outdated STRs instead of SNPs? Rather surprising from the University of Zurich.

agree they could have done better in the year 2024
they only checked the predicted G cases for farther snp downstream branches of G

We examined uniparental markers, including whole mtDNA sequences as well as 23 Y-STR markers and a set of 5 G-haplogroup-defining Y-SNP markers. We scanned for signatures of population structure in the 23 Y-STR markers through the construction of a median-joining network of individual haplotypes (see Supplementary Table S5 for the haplogroup assignments).

p.s
side note the 23 y-str (promegea) markers they used are very informative
i took the markers they used in the paper:
DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS385 a/b DYS448, DYS438, DYS437, DYS635, DYS439, DYS458, DYS456 Y-GATA-H4, DYS481, DYS533, DYS549, DYS570, DYS576,DYS643.
and put my own values from my own ftdna y str markers
and it predicted me in nevgen predictor as 99% e-m84
so while for sure snp is more informative than y str prediction
those 23 markers indeed can nail at least the direction of the predicted y haplogroup

 

[Riverman]

11 E-V13ers from this paper. Really annoying that they didn't make any high resolution SNP based analysis on them, since they are a candidate group for having my branch members included. If I'm not mistaken the confirmed E-V13 frequency is 6 % in the total sample.

 

[kingdavid]

11 E-V13ers from this paper. Really annoying that they didn't make any high resolution SNP based analysis on them, since they are a candidate group for having my branch members included. If I'm not mistaken the confirmed E-V13 frequency is 6 % in the total sample.

Yes
almost all the e1b1b1 samples are e-v13
With the exception of 3 cases :
1 e-v22 from Bosco-Gurin
1 e-m81 from Safiental
1 e-m123>m34>z841 from Thusis

I think e-v13 might be old in the region
Likely iron age ( could be wrong though since you are the expert in this stuff)
It is indeed a shame that they didn't test for snps

 

[Riverman]

Without having the subclades, we can't even guess when they arrived there. We really need ancient DNA samples on a larger scale for various time periods to be sure. However, in South Western Germany some branches are extremely likely to have arrived in the La Tene period, since they started to diversify then in situ, at least based on modern sampling with multiple subbranches dating to that period. But what we got there, in this sample, is impossible to tell just based on their V13 assignment.

 

[kingdavid]

Without having the subclades, we can't even guess when they arrived there. We really need ancient DNA samples on a larger scale for various time periods to be sure. However, in South Western Germany some branches are extremely likely to have arrived in the La Tene period, since they started to diversify then in situ, at least based on modern sampling with multiple subbranches dating to that period. But what we got there, in this sample, is impossible to tell just based on their V13 assignment.

this future paper
not ancient dna from Switzerland but rather from not far geographically Austria
it could be relevant to e-v13

 

[Riverman]

Yes, that's a highly interesting paper, even just based on the size of the sampling, which might be pretty complete for this part of the world. 235 individuals is something.