One subject that has often been overlooked, is the genetic influence of the first megalith builders of Northern France. This location is meeting point between Danubian and Cardial Neolithic groups. Not only that, but also mixture with Mesolithic hunters of the region. This mixture can be seen quite clearly in the mtDNA (Rivollat et al, 2015; LeRoy et al, 2016). The one thing that is also questioned is just how much genetic impact did Megalithism have on the genetic make-up of Northern European farmers of the Middle and Late Neolithic. Is this a movement of people, or “monumental” ideas?
Since early times, the movement of farmers to Britain was seen as a movement from France, from Michelsberg, or related groups (Childe, 1931). To test this idea, I used datasets from Lipson et al, 2017; Olalde et al, 2018; and Mathieson et al, 2018) to look for a relationship using qpGraph.
Not only are the samples from Southern France and England alike, they are basically identical! Both are probably rooted in the Paris Basin, showing Danubian, Cardial, and Mesolithic roots. As the link is shown below, in Le Roy et al (2016). Also, note the shift towards France, by later Central Farmers of the Middle to Late Neolithic.
Below, is the first graph, showing the genetic ties between England, and Southern France. Both are likely from the Paris Basin group.
D-stats showing France_MN and England_N as a clade
Graph with England_N alone
German Middle Neolithic Funnelbeaker
This same set-up is the one I used to then find the relationship to later Megalith building cultures. The first one I chose to look at was the Funnelbeaker samples from Germany. The surprising thing from this graph is that the German Middle Neolithic samples (minus the Roessen sample) were almost exactly like the England and French Neolithic samples, with a slight bit more Danubian admixture.
Attempt to create TRB-Germany without admixture from French-related groups
The first graph, is just Germany_MN, uplaced, with the worst-Z being one that asks for Germany_MN and England_N to be closer.
The second graph forces Germany_MN to be attached to LBK
The worst-Z from this graph asks for WHG to be closer to Germany_MN. The following graph includes an edge from WHG to Germany_MN.
As a result of this graph, the worst-Z now asks for Germany_MN and Iberia_EN to be closer. Due to this, a migration edge from Iberia_EN is added to the next graph.
This last graph has many issues. Not only the zero drift edges, but a migration edge of 0% from Iberia to Germany and a worst-Z still not resolved. It seems that deviating from the desire to connect Germany_MN and England_N caused the poor outcome.
Iberian Middle Neolithic at La Mina
The second group that I looked at was the Middle Neolithic group from La Mina, in Northern Spain. Once again, the Middle Neolithic population was almost identical to the group with roots in France. Specifically, those that moved to Southern France.
While Gokhem2 does not have as much coverage as I would like, I thought that they would also be good to check, to make sure they are also rooted in the same group. As suspected, she was also almost exactly like the English and French samples.
Globular Amphora in Poland
Since Globular Amphora is supposed to come out of the TRB group in Northern Germany, I thought that I would also take a look at them and see if they are also closely related to the farmers from France. They also turned out to have a great deal of their ancestry from this group.
So, the picture that is emerging is that at one time, groups from Iberia, to Britain, up to Scandinavia, and all the way to the steppes of Ukraine were rooted in the French Middle Neolithic.
D-stats suggestive of Cardial gene-flow
Now, Chimp does have its shortfalls, such as the branch-shortening effect, and ancient attraction, but it is basically symmetrical in relationship to each of these samples. However, the same can not be said for Africans. That is the reason that I have not included them in these graphs. Now, with them, the graphs really don’t change, but you can have the need for edges from farmers to Africans. Farmers, specifically those from Europe, are much closer to basically all Africans, when put against ENA, hunter-gatherers, and more basal sources, such as Natufians.
This is reflected in graphs, and also D-stats. Now, how this is so is the big question. We may see farmer movement taking R1b-V88 and Iberian ancestry as far as South_Africa_2000BP, or something such as ascertainment bias. The fact that Malawi_Hora_Holocene_8100BP is also showing this is quite puzzling and leaning me more towards some kind of bias. The likelihood of a migration of something like a Dzudzuana to SE Africa that early could be possible, but without the actual sample, that is hard to test.
Testing with qpGraph also always resulted in gene-flow from a source like Iberia_EN, and sometimes also from Iberomaurusians (IBM). Mbuti is not bad, in that it is nearly perfectly aligned with Danubian and Cardial sources, the problem lies in the HG stats, where Mbuti does want to be closer to farmers than hunters, and the flow is always to Africa. Testing with flow both to and from Iberian farmers illustrates the same with all Africans in a tree. Here is a tree with South_Africa_2000BP as an example:
This asymmetry makes me wary of including them in analysis that includes both hunters and various types of farmers. I also feel adding too many more admixture edges will be distracting and admixture from Eurasians to Africans does need more ancient samples to resolve whether these are all legit or not.
Trying to create a graph without Chimp does lose a more neutral source for sorting out this farmer and hunter ancestry in Northern Europe, although it does seem minimal, judging by this basic tree involving England_N and France_MN. It seems the most affected is the actual Cardial ancestry in the samples. They become less Cardial than Danubian, in the tree not involving TRB samples, but actually are now closer to what they were with the other farmers involved in the tree.
However, moving onto Germany_MN, we see that Chimp would make the fit better, decreasing the worst Z that seems to want more Cardial influence to England_N.
Including Mbuti into the Analyses
As expected, adding an African to a graph, when they are not symmetrically related, created a graph that becomes overly complicated and does not match other statistical methods. This includes haplotype analysis of an Irish farmer that shared more ancestry with Cardial than Danubian farmers.
Melie Le Roy et al (2016)Distinct ancestries for similar funerary practices? A GIS analysiscomparing funerary, osteological and aDNA data from the Middle Neolithic necropolis Gurgy “Les Noisats” (Yonne, France) http://dx.doi.org/10.1016/j.jas.2016.07.003