For starters I will point out that there is a difference between our ethnicity, our race, our nationality, and our ancestry. These terms tend to be used interchangeably but there are important different in the terms- which can be Googled... I know a large number of people who are American in nationality will identify their heritage saying their "nationality" is Irish, Polish... What they really mean is their ancestry. Also a lot of third, fourth and fifth generation Americans who use fractions such as being 50% Slovak, 3/4 Russian, 1/8 English...All people have 8 Great-Grandparents so we might as well go by 8th's (My roots are simple all 8 are from Italy). There is nothing wrong with any of this, ethnic pride can be a good thing unless it gets divisive. In that case we all can just say were 100% Mesopotamian. What I'm getting at is there is an even deeper way to look at this. For one thing countries tend to change borders frequently. Ethnic identities don't always correlate with political borders, and some countries which people identify with a country that didn't even exist before their ancestors came. If Mars took over the US and forced their language on us for a few years would that make us Martians? While it's fun to identify and celebrate our cultural roots they are certainly not absolutes.
I've been reading up on the National Geographic's Genographic Project where researchers collecting samples of DNA from thousands of people along with other information on their background. This will help us get a more accurate view of history and human migrations. I am hoping that only good comes out of this and that such information doesn't get abused if it gets in to the wrong hands. I know this whole project is controversial but I try to be optimistic. It seems so far the results of all this DNA testing are fascinating and challenge a lot of our thoughts about our identity. According to this project it seems humanity all migrated from Africa and then spread. I took part in this project since I like history and research though the results are tricky to understand. The tests can tell which DNA Haplogroup one belongs to. This is not the same as being told that you that your Great-Great-Grandmother was from Syria and another from Lithuania. Such ethnic identities didn't even exist thousands of years ago. Italy wasn't even unified until the 19th century, so what does that make me now? Also people moved from place to place constantly. When people think "hmmm... people of country X have red hair- maybe it has something to do with their climate?" Not necessarily, people didn't necessarily evolve in the land of their most recent foreign ancestors. This also shows that no one is really pure anything in any absolute way. I know studies like this can be used for good or bad and I don't know enough about it to judge. I am hopeful that new science can challenge peoples' prejudices and get people to start questioning their divisive ways. People may start to realize that those they have ancestors in groups they were once bigoted toward (as was the case in Poland where a Neo-Nazi couple found out that they were Jewish). I feel research like this can be used to promote peace- if it is done thoughtfully.
Here is a link to the project I was discussing: https://genographic.nationalgeographic.com/genographic/index.html
This is the village in central Italy where both of my Father's parents were born (my Mother's side was from further south):
Nocera Umbra, by: A. Fabbretti, 1988