Ancestry DNA testing has come around now in a time of materialism, ego, instant gratification, attention seeking, socio-political agendas, and a lack of knowledge about history, so it should be of no surprise that there have been some problem areas. The first problem is that people can't truly even read and comprehend the tests. These "ancestry groupings" are somewhat arbitrary, and mix sub-markers of both very ancient and more contemporary admixtures into single groupings. For example, lets just say that my test showed that I'm 6% from "Turkey." That would not mean that I have Turkic DNA. The land now known as Turkey was once basically of varying regions, eras, and mixtures of proto-European, Mediterranean, Greek, Roman, and a type of Celtic people. In other words, European. Only about 900 years ago was it overwhelmed by Turkic tribes and took on a Turkic, Islamic, and non-European identity. However, on the test they don't make any before-and-after distinction for that 1,100 CE racial timeline change. The subject is just left to scratch their heads and say "I guess I'm part Turkish" and apply a false mindset.
One of the common features from test results of Mexican, Puerto Rican and most other Latin American origins is that those people are virtually always at least partly Iberian. Within that Iberian DNA structure is a proto-European link with the British Isles. This pretty much is not related to the overall root stock of today, but of very ancient origin. Proto-Europeans were not Teutonic or Mediterranean, but the stock of the first Europeans; for example, the Basques or the Welsh. Still, there's the "BRITISH???" reaction from the test subjects. Just like the vast majority of people, they simply cannot process the results properly because they don't really know what they're reading. For some reason, whatever that particular conflated Iberian-British sub-marker is.... it was placed under the "British" category in the results. The Puerto Rican guy's "British" ancestors probably didn't look like Sting or David Bowie, or what we would perceive as modern day root stock British.
It probably should be noted that there's a significant difference between racially-mixed and ethnically-mixed. Someone who is Irish and Ukrainian is ethnically-mixed; someone who is Irish and Mestizo is racially-mixed. On one Ancestry By DNA commercial, a Mexican woman said she just thought she was "Hispanic," whatever that meant to her. After taking the test she was so overwhelmed that she said "I'm everything!" She probably misinterpreted most of it. For example, the Iberian component might seem to reflect an exotic mix when that may not necessarily be the whole truth. For example her possible ancient Briton, Phoenician or Greek admixture would not be the same as her Mayan or Congolese admixture. She was basically Mestiza with perhaps 7% West African admixture; it's not really that complicated. In other words, certainly in today's world, there are a lot of DNA markers which reflect a similar ethnic origin or type anyway.
Since the ancient Etruscans were known to have migrated from the region now known as Anatolia in Turkey, this presents another problem in test results. Those people who later became known as the Etruscans were obviously an intelligent, creative, and successful people; these "Anatolian" Mediterraneans may have branched out in other directions. Therefore there could be people in say the near east who could take a test and it would show the "Italy/Greece" or "Italian" trace marker. It's possible that it could be from some ancient Roman colonizers, but I have no doubt that sometimes it could be the conflation of modern Tuscan DNA with "ancient Anatolian." In other words, that person's ancestors never stepped foot on the Italian peninsula, but they have that particular DNA maker from people whose progeny came to be the Tuscans at a later point in history!
There's usually a reason for everything. For example, a Puerto Rican could discover that they're part "Italian," and not just a trace amount from "Roman Spain." For some reason, long ago there were some immigrants from Corsica, Sardinia, and Ireland into Puerto Rico... but they did not remain a separate people, but merged with the local population mix. It probably should be noted that most of "Italy and Greece" are closely DNA linked, but not "Italy and Spain" despite the closer comparative linguistic link with Spain. DNA tests aren't always consistent. Sometimes siblings get different results. Sometimes smaller admixtures don't show up, or sometimes they're blown up on a test. In other words if someone was of a 3% admixture, the result might show it to be 10%. One test result in regards to an admixture stated "Your ethnicity estimate is 4%, but it can range from 0-20%." Doesn't sound very reliable, unless you took at least three tests and averaged them. There have been Nigerians who have taken the test, people whose families have always been Nigerians as far as they know. To their surprise they discover that they're only 30% Nigerian, with the rest being other regionally conflated DNA groupings that they don't even understand.
One of the absolute absurdities finally put to rest is Quentin Tarantino's "black Sicilian" myth from the film 'True Romance' from 1993... prior to the availability of these tests. Even though that had nothing much to do with our people, it was still a false narrative. Also, if you may recall, our people were mentioned in the script for that scene; something absurd like Sicilians were once all blonde haired and blue eyed just like in the north, then they were overrun by blacks. People actually believed that or wanted to believe it, especially if they didn't like Sicilians or Italians. As if there were never any Proto-Europeans or Mediterraneans, or even various darker skinned peoples to the south or east. Not that I think anyone really cares about that scene, but no part of it was generally true. I guess Tarantino assumed that Spanish or Arabs were already perceived to be mixed, but the scene could work within the context of white Sicilian criminals. For the record, I don't have any problem with Sicily or Sicilians; I just want a homeland specifically for our people--and only our people--just like the Jews and Japanese have. That's it.
One of the more interesting test results I've seen was one from a Coptic Egyptian woman. She truly was heavily of ancient Egyptian origin, probably without any significant change. She only had 0.7% European and 0.1% Sub-Saharan African. The Coptic Christians go straight back to ancient Egypt. It should be noted that there actually is a "North African" DNA category; totally separate from Sub-Saharan African. In other words, that particular DNA marker is not Sub-Saharan, but comes from the ancient migration of people from west Asia who after a long period of time developed genetic uniqueness. However, that's only in regards to that particular innate DNA category, not for the modern population of North Africa which is very mixed racially. Another important fact is that the DNA of specifically the Persian people (not the little dark Afghani types) clusters very closely with Europeans despite a long separation of time. Ancient Persians were the Aryans; there's no ifs, ans, or buts about it. They were of an ancient local Mediterranean and ancient north-Eurasian Teutonic mix. Admixtures to Persia/Iran have been relatively minor since that time.
The only truly strange admixture I ever saw was one Algerian woman who had a trace marker of Australian Aborigine. There are legends about the Phoenicians having traveled as far as Australia, but nobody really believed them. Well, maybe that's the proof that those legends are true.