How was I "proven wrong" and how is your "a simple and very brief clarification of [that] reality", and how is this "obvious that south Italians (or Greeks) have large extra-european admixture"? I'll bring up just the most recent paper,
https://www.biorxiv.org/content/10.1101/2022.02.26.482072v1, but it is already a known fact that the the majority of the literature, up to now, doesn't support such claims. It is getting tiresome that such claims just keep getting made without further backing up because, it is said, "they're obvious", yet the literature doesn't back them up.
To briefly state what the "state of the art" is up to now, it's true that south Italians and Greeks have higher affinities towards middle easterners because of their higher caucasus-related ancestry compared to other Europeans, and I agree that it is useful (not "ontologically true" or as "natural kinds", for those more philosophically inclined) to distinguish between "Europeans" and "Middle Easterners", since as intra-caucasoid groupings they seem very reliable and "real" as far as it is very easy to tell them apart, though I'd add that "Middle Easterners" ought to be broken down into further subgroups and as a label "Middle Easterner" just stands for "Not European". However, these are groupings that came to be during the bronze age, and the gene pool of Italy and Greece were either largely formed by its end or further contributions came from inside Europe (barring maybe some further Iron age augmentations from Anatolia and the known low levels of north African in some southern Italians), as the extra CHG Greeks and Italians carry was already present in similar levels in samples from all the way back to the Mycenaean period. If caucasus-related ancestry by itself is "extra-european" because it peaks in Caucasians-whereas, for example, Anatolian neolithic related ancestry peaks in south west Europe-, then we must also coherently say that north Europeans are less European than south west Europeans or than Sardinians because the steppe component which in Europe peaks in the north carries 40% caucasus-related ancestry. Said otherwise, the components in south Italy and Greece's gene pools were already present during the BA, the period the "European" and "Middle Eastern" gene pools formed, and it doesn't seem that further contributions from the Middle East are needed in order to explain the south Italians and Greeks' genetic make up, and actually there is evidence AGAINST such scenarios (for examples that haplogroups don't add up).
Since you brought up appearance as a kind of evidence, though it is not since we're strictly speaking of genotype/autosomal, I'd say that you're an American that hasn't set foot in Italy: as an Italian, precisely some one who has always lived in Sicily (Sicilian from mother's side, Emilian from father's side), it is my experience that it is extremely easy to tell apart "east meds", by which I take you mean Turks and Levantines, from all Italians, and usually it is Americans because of debatable casting choices made by Hollywood or other pop culture phenomena (including cherry-picked photos on the internet) that think otherwise. It may be true that such judgements are subjective and lack any substance to them (why I prefer to speak about autosomal), and it isn't to deny the existence of "funny looks" in Italy, but since it has been brought up I'll say that to me and the persons I've interactions with it is extremely easy to tell apart us Middle Easterners, indeed common folks in Sicily call every one that is visibly darker than us "Turcu", "Turk", and our "funny looks" are different from what we can call "east med" looks.
etras_EBA