Yeah samples matter. I wonder if the cypriots in that study have greek blood? They're in line with south italians but in most maps they usually plot south of any european. And Spaniards usually are a bit higher than north italians in most other maps but those are likely the Catalans you mentioned.
Then again I think reading percentages and numbers would be more informative. A half orcadian half Lebanese would plot as north as Georgian jews in the left map while still having higher north european percentages than them. Its a matter of having enough Levantine blood to plot there.
PCAs only say where one plots, not why. At least that's my guess. The explaination rests on actual numbers and percentages. Am I right?
Generally true, I think, but again, what is being relied upon? If it's the same old unverifiable results from something like Gedmatch, how reliable are those percentages?
As I pointed out above, someone tells you he's 100% X ancestry. How do you know that's true? Maybe three grandparents are from that region, but one isn't. Or, the person publishing that information may not be being truthful. It's a sad fact that this hobby is riddled with racists of one variety or another, or just seriously neurotic, if not psychotic people. We've had some recent "unmaskings" right here on this board. Would you rely on something relayed to you by a person like that? I wouldn't.
Then, it's an Admixture program, which can be useful, but definitely has its limitations. The results have to be interpreted by someone who understands Admixture, not some half educated yahoo on the internet. Where the samples were taken is also very important. To use our example from above, how representative of the Spanish as a whole is a sample that is 50% Catalan? Also, who created it? Was the sampling balanced, or was it done to "highlight" certain ancestry? A whole article was issued recently pointing out the errors that academics have made in running Admixture and drawing conclusions from it, so how much worse are the problems in amateur created programs?
The problem with genetic genealogy is that genetic results are being "interpreted" or disseminated by people who either don't have the background to understand the material, or have ulterior motives. I've personally seen people disseminate absolutely falsely labeled material. Why would I accept anything a person like that presents as "proof".
It's like a witness who impeaches himself or herself.
Just look at people who have posted here presuming to instruct the rest of us what people from various parts of Italy look like,
when they've never set foot in the country in their entire lives. And no, it isn't the same thing to be around some Italian Americans in one particular American city. I've lived among them, married among them, and most of them, unless they're in their 90's and actually did the immigrating, don't have a clue in what particular towns in Sicily, for example, each of their four grandparents originated. All my husband knew was the province. It's pathetic. Plus, this is going to be a subset, and not necessarily a representative subset. Then, the idiocy continues by comparing their appearance with that of various middle easterners, of whom they've probably met a handful in their lives. The chutzpah is pretty amazing.
So, always, it's a case of "buyer beware". The gullibility of people in this field, even academics at times, is really astounding. They need to spend a couple of months in any criminal fraud bureau.
