The study said the Greeks didn't have any admixture and they were outliers on the PCA, or that they threw a wrench in the whole thing and thus discarded them i guess.
"We curated these data using Principal Components Analysis (PCA) [16] (Table S2), with the most important steps being: (i)Removal of 140 individuals as outliers who did not cluster with the bulk of samples of the same group, (ii) Removal of all 8 Greek samples as they separated into sub-clusters in PCA so that it was not clear which of these clusters was most representative, (iii)."
Another thing of note is it is Interesting that the STRUCTURE results came up with some pretty significant differences between their 'new methods'. In the study, the STRUCTURE results had the Sardinians and Northern Italians only 0.2% admixed while using their 'other method' they came out 2.9% admixed...so it's probably best to go with STRUCTURE results for all groups IMO. This type of discrepancy wasn't in other samples like the Palestinians, who are known to have Negroid/Sub Saharan admixture.
But another flaw of this study is the sample sets, they got it from the PORPES database and much of the database got their samples from diaspora populations and almost half of the samples did not have the origin of any grandparents observed.
So anyway, not very conclusive IMO.
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