Italian Peninsula G25 Analysis

[Ethel]

G25 (scaled) maps for the averaged three main regions of the Italian Peninsula as of 03/2020 (subject to reference changes).

Southern Italy (Italia Meridionale)



Central Italy (Italia Centrale)



Northern Italy (Italia Settentrionale)



G25 Scaled PCA





Notes:

• Basilicata was used as an AVG reference for South Italy, as it's not as mainland-shifted as Sicilian_West, Molise and Abruzzo, but also not as outlying as Campania, Calabria and Sicily_East. Apulia could also be used but it has a notable Greek bias;
• Umbria was used as the AVG reference for Central Italy, as Lazio has a few southern-dielact speaking communities and Tuscany is too northern shifted;
• Bergamo is the AVG reference for North Italy because it's the very center of the Po Valley without the Bavarian shift that Triveneto has, nor the French one that pushes Piedmont and Aosta;
• Piedmont, Swiss_Italian and Moldavian references are broken and unreliable;
• Emilia-Romagna was estimated with an average of defective references of Piedmont and Swiss_Italian compared with Tuscan;
• Swiss Italian (Ticino) was calculated as Lombardy, as they speak the same "dialect" (they're the same people);
• Piedmont region was calculated as an average between Lombardy and Aosta;
• Moldavia_o reference was used to paint its region on the map, since the standard G25 Moldavian was causing an abnormal hotspot;
• Some countries that aren't separated into regional references by the G25 had to be separated into different tones in degradée following the patterns according to their neighboring countries. This made the gradient on the map smoother and more realistic, but it may not be completely reliable;
• Turkey was extremely difficult to place because there are many references that are contradictory and many areas without references, so it appears kinda retarded on the map compared to the other regions.

Conclusions:

× The Italian Peninsula is a genetic cline that goes from Lyon to Crete, with the Iberian and Greek Peninsulas as genetic parallels, and this is reflected on G25;
× We desperately need at least a reference for Emilia-Romagna, and a better one for Piedmont;
× Campania should also be separated into Mainland and Coastal;
× Sicilian_East is odd because it's probably based on Messina, which is quite different from Ragusa and Syracuse, the latter needing a separate sample for them;
× I still prefer K36 Taux de Similitude maps a bit more even though they aren't perfect as well.

[Samnium]

The G25 reference of Calabria is made by 2 samples coming from the same area (Reggio Calabria).

There are other heavy problems with Italian references.

+ these similarity maps in my opinion are very inaccurate

[Token]

The G25 reference of Calabria is made by 2 samples coming from the same area (Reggio Calabria).

There are other heavy problems with Italian references.

+ these similarity maps in my opinion are very inaccurate

Calm down dude, there would be more Calabrian samples if they existed.

[Token]

I see recent Austrian ancestry in Triveneto and recent mainland Greek ancestry in Apulia, and both are characterized by some degree of Slavic admixture.

[Jana]

Break in Med continuity on western Balkan coast is clear proof of mass Slavic invasion of our ancestors Meanwhile, eastern Balkans is much more Med, reflected nicely in east Romance languages surviving there.

[Ion Basescul]

Break in Med continuity on western Balkan coast is clear proof of mass Slavic invasion of our ancestors Meanwhile, eastern Balkans is much more Med, reflected nicely in east Romance languages surviving there.

[Token]

Break in Med continuity on western Balkan coast is clear proof of mass Slavic invasion of our ancestors Meanwhile, eastern Balkans is much more Med, reflected nicely in east Romance languages surviving there.

If Slavic invasions had never occured Croatia would be in deep green in the North Italian map.

[Ethel]

I see recent Austrian ancestry in Triveneto and recent mainland Greek ancestry in Apulia, and both are characterized by some degree of Slavic admixture.

Weirdly enough, Apulia is less Greek-shifted than Basilicata here, which is a very "neutral" or isolated Southern Italian region
It’s sad that a big country like Germany is so underrepresented, there are only two references, I had a hard time trying to divide it, then you have Catalonia with a dozen references .
This also makes it difficult to tell which way Triveneto is shifting towards to, and you won't see it at the similarity map because it was made based on Bergamo.
I think that the lack of a Piedmont reference leaves Aosta misplaced. In all genetic reports I've seen, Northern Italy is bifurcated into two clines, one towards Bavaria (which we can't confirm because there's no reference for it) and other to France.
One thing we can confirm is what I've always thought: Liguria, Lombardy (and possibly Emilia Romagna) are the most similar regions to Sardinia and Iberia.

I'm adding this PCA to the main post too.

[Raizen]

Interesting. My Venetian side is Veronese and Italian_Lombardy/Italian_Bergamo are the best references for this side of my ancestry. I think it makes sense since this part of Veneto was inhabited by Gallo-Romans, similar to Lombardy, and Orobic Lombard is still spoken in some cities of Verona. I'm a mix of many things anyway, so maybe this is just G25 not being able to separate my ancestries with full accuracy.
Couldn't this Austrian shift in eastern Veneto be an ancient Adriatic Veneti thing?

[Ethel]

Interesting. My Venetian side is Veronese and Italian_Lombardy/Italian_Bergamo are the best references for this side of my ancestry. I think it makes sense since this part of Veneto was inhabited by Gallo-Romans, similar to Lombardy, and Orobic Lombard is still spoken in some cities of Verona. I'm a mix of many things anyway, so maybe this is just G25 not being able to separate my ancestries with full accuracy.
Couldn't this Austrian shift in eastern Veneto be an ancient Adriatic Veneti thing?

I suppose Verona follows a similar pattern to Brescia (East Lombardy), it's in Vicenza where things start to get weird. Usually they group Venetians with Cisalpine Gauls because they were quite similar and their language still fits in the Gallo-Italic group, I remember a study that Token shared here showing that the Venetic language had more similarities with Gallic, but also strongly similar to the Italic ones.

I think it's safe to say that Triveneto is more Bavarian shifted than Austrian, the latter being more distant from them and more eastern too. What makes Triveneto uniquely shaped like that is a combination of those Gallic-Venetic plus Rhaetian/Adriatic influence, and it also seems to be the most affected region by Germanic invasions. I think consistent slavic input is only seen in the eastern fringes of Friuli, bordering Slovenia, not in Triveneto as a whole.