Raveane et al. (2019) show that genes mirror geography, but then they make a misleading claim implying that genetic distances (Fst) within Italy are as great as those
"across the whole of Europe". To Nordicists who
wrongly believe that only their corner of Europe is "fully European" and the others are "mixed", that kind of distance perpetuates the
myth of racial differences between Northern and Southern Italians.
But we already know that
all Italians cluster between Spaniards and Greeks, which would make "across
Southern Europe" a more accurate statement. So what exactly are the authors talking about?
They base their claim on the finding that the median Fst between all of their Italian clusters is 0.0044, which is about the same as the median Fst between all of the European clusters (excluding outlier Finns), and higher than within any of the other countries examined (0.0001 to 0.002). They say that they got similar results after also excluding outlier Sardinians and Basques, but don't show the data.
However, they're still including the Northern Italian clusters from the small regions bordering France, Austria and Slovenia that have many outliers as well, which increases the genetic distances. If you just compare typical Northern Italians (from Piedmont, Lombardy and Veneto) to deep Southern Italians (from Puglia, Basilicata, Calabria and Sicily), Fst between them ranges from 0.001 to 0.0054, with a median of just
0.0024, and an average of
0.0029.
That's not too much higher than the maximum distances within the other examined countries, and it's a lot lower than truly cross-Europe Fst, which ranges from 0.005 to 0.011 between Iberia and Eastern Europe (med.
0.008, avg.
0.0077), and from 0.004 to 0.008 between Greece and Northern Europe (med.
0.005, avg.
0.0055).
It also happens to be the same as the Fst between Southwest (Spain) and Southeast (Greece) Europe (0.002 to 0.003, med.
0.003, avg.
0.0029), which is itself lower than the Fst between Northwest (Britain) and Northeast (Baltic) Europe (0.003 to 0.007, med.
0.005, avg.
0.0049).
[
NOTE: The highest in their data is
0.02 between Finns and Basques, both of which I excluded from all the above calculations, along with other outliers like Orcadians and Mordovians.]
So even though genetic distances in Italy are somewhat high for a single country, they're not as extreme as implied, and they don't represent any kind of "racial" or other significant difference, but merely a
normal cline that's entirely within Southern Europe and likely related to the
ancient spread of Indo-European languages.