The Italian study of Bologna University "Ancient and recent admixture layers in Sicily" shows that tosks and ghegs differ in autosomal DNA as well as in the y dna with the tosks being more european like and ghegs more eef like even if they are geographically to the north.(take a look in the supplementary figures)This means that ghegs are less influenced by their neighboring peoples because of their isolation.And as far as i know they also differ linguistically and phenotypically.One of the factors that contributed to their differentiation is the mixing with Greeks, as the ancient Greek colonies, geography and the presence of a Greek minority suggest.So it is not a question of if but rather of how much they were influenced by the Greeks.
BUT WHAT I DO NOT UNDERSTAND IS HOW YOU TURNED ONCE MORE THIS DISCUSSION ABOUT GREEK REGIONAL Y DNA GROUPS IN A DISCUSSION ABOUT THE ALBANIANS.
Did we actually read the same paper? If I was you I wouldn't bring it up lol, because it just further solidifies my point that northern Greeks (Thessaly, Epir and Poleponessos) share descent amount of their ancestry with Albanians (Tosk and Gheg) including Kosovars who are Gheg Albanians, and that Albanians don't differ greatly from each other. It's a known fact that Tosks have absorbed more Slavic influence but how that makes them more similar to Greeks I haven't been able to get it out of you guys yet. Furthermore, it's hard to make out the labels on the PCA, but I see Tosks and Ghegs clustering nicely on the left not that distantly from each other while Greeks are all over the place
Modern Southern Italian and Southern Balkan populations are located at the centre of the PCA plot (Fig. 2, Supplementary Fig. S1), forming an almost uninterrupted bridge between the two parallel clines of distribution where most of the other modern populations are found, one stretching along the East-West axis of Europe and the other from the Near East to the Caucasus, respectively (see also Supplementary Information). In particular, Sicily and Southern Italy (SSI) appear as belonging to a wide and homogeneous genetic domain, which is shared by large portions of the present-day South-Eastern Euro-Mediterranean area, extending from Sicily to Cyprus, through Crete, Aegean-Dodecanese and Anatolian Greek Islands. We will refer to this domain as ‘Mediterranean genetic continuum’. On the other hand, the continental part of Greece, including Peloponnesus, appears as slightly differentiated, by clustering with the other Southern Balkan populations of Albania and Kosovo. Finally, North-Central Balkan groups (Southern Slavic-speakers and Romanians) show affinity to Eastern Europeans (Fig. 2, Supplementary Fig. S1, Supplementary Information).
Even the paper was postulating that Greece probably went through some drastic population changes ever since their glory days, hence why the aforementioned regions are more related to Albanians and show no affinity to their comrades across the sea. You first have to define what represents a Greek and then come here and tell us what we are and single out our 'Greek' influence lol