Coming to think about it all, I think you guys have already convinced me in persuasive and strong enough words about the fact that amateur tools and hobbyists' interpretations of imperfect tools used by them are totally dismissable when you have the words of actual professional geneticists who certainly understand those samples and tools, as well as complex statistics much better, and surely try all the hypothetical ancestral models that could at least be plausible before deciding the one that has the best fits and is the most parsimonious and credible explanation for the genetic structure that they're seeing in the samples. Since we can think of these models, choose the most likely source samples and try several distinct models before deciding which is the best, professional geneticists can and certainly do that even much better and more intensely.
Therefore, I was a bit frustrated that the recent genetic papers on Italian aDNA samples seem to have lacked a comparison of the models used for the aDNA amples with samples from the modern populations in the same region, but apparently I hadn't read it all, and I'm glad to say that that had in fact been done by Fernandes et al. (including such luminaries of population genetics such as Olalde, Lazaridis, Reich etc.) in the very recent 2020 study on Neolithic and BA Sicilian and Neolithic/Chalcolithic/BA/IA Sardinian aDNA samples. It's only in the supplementary material, page 29 (
https://reich.hms.harvard.edu/sites..._NatEcolEvol_WestMediterranean_Supplement.pdf).
Image of the models:
https://imgur.com/a/kjWn0tu.
Later in the supplement the authors assert that:
"The two Middle Bronze Age Sicilian individuals can only be fit parsimoniously with the modelrequiring Iranian-related ancestry (15.7 ± 2.6%, p=0.060) while the model that used onlyYamnaya_Samara ancestry as a source does not fit (p=2.21E-04) (Supplementary Table 14).
In Late Bronze Age Sicily at the site of Marcita, our qpAdm models required only the presenceof Anatolia_Neolithic (81.5 ± 1.8%), WHG (5.9 ± 1.6%), and Yamnaya_Samara (12.7 ± 2.1%).
We were able to model modern Sicilians with a 4-way model that included 23.2 ± 4.2%Anatolia_Neolithic, 19.9 ± 1.4% Yamnaya_Samara, 10.0 ± 2.6% Iran_Ganj_Dareh_Neolithic, and 46.9± 5.6% Morocco_LN (p=0.522) (Supplementary Table 14)."
Therefore, it seems that, according to the very renowned Reich's lab, all my amateurish models pointing generally to a
high genetic continuity plus 5-12% Levant_N (using Barcin_N) or 2-8% (using a pool of all Anatolia_N samples) + a bit extra Steppe_EMBA + 2-3% Morocco_EN for Sicilians were indeed totally incorrect, and in fact the picture is very different from what I thought was most plausible and likely an explanation for the current average genetic makeup of Sicilians.
The modern Sicilians, according to those reputable authors, appear to be a completely different population according to the best fit model that they picked to publish
(as some Eupedia members stressed before, it's hard to believe they don't use several different combinations of source populations, according to several at least hypothetically realistic scenarios, before determining which makes the best fits). The authors, who know a lot more than us hobbyists and are thus much less likely to commit any basic mistakes
(that's also another reason why we should, for example, try to understand why they are using Levant_N to model aDNA Northeastern European BA samples instead of Anatolia_N in the recent Fatyanovo paper, for that is obviously not just a crass mistake that not even amateurs would do), seem to be pointing out a really massive post-BA genetic change in the direction of North Africa, quite on the contrary of what I had thought. It isn't only the large Morocco_LN admixture, the non-North African admixture composition also appears very different from earlier periods, as you can see here:
https://imgur.com/a/LWXu2Ye
Professionals always know it better than us all, right? Therefore, until further and much needed archaeogenomic studies on Italian and Aegean aDNA samples are published, I guess we all ought to take it as solid provisional scientific understanding that modern Sicilians are very different from the EBA, MBA and LBA Sicilians and ~50% Berber/North Moroccan-related Morocco_LN, strange though those results may be when we compare them to all the models made using amateur tools and a few previous models made some time ago, with a less developed science of population archaeogenetics.
Thus, I think we should keep this discussion partially on pause mood until more aDNA samples and other professional geneticists' studies are released (I hope sooner rather than later). Science is always a falseable (in the Popper sense) field of knowledge, it has provisional, temporary truths that are much better than the former truths and (hopefully) worse than the future truths.
For now, all we can say, based on what real scientists have found so far, is that Sicilians (maybe also South Italians, since they are closely related) shouldn't be understood as basically ancient (pre-IA) Italians with a bit more Levantine, Iran/CHG and Yamnaya ancestry, but as a more recent population with a very heavy North African input. That's what Reich's lab in a study made by some of the best population geneticists assert, so it must be much more credible than my own explanation, for which I am sorry I have insisted so much on.