I asked: Through the testing is there anyway to identify what part of Europe our family came from? I also did the DNA testing with Ancestry where they indicated British Isles. Per my father he had always thought Scottish or Irish.
Roger Alexander who leads the Alexander DNA Project responded;
Not to be picky, but to start with, in your definition, what is your “family”? When your ancestors took on the Alexander surname? That would be ca 1300 when the government wanted to identify everyone so it could make sure everyone was taxed. The answer is likely Scotland. Society was tribal, called clans. McDonald’s were big and it is likely the Alexander’s came from the McDonald’s to some degree.
Your dad’s speculation an Irish origin is likely due to the possibility his Alexander ancestors migrated to the colonies/US from Ireland. But Alexander is not an Irish name, but Scottish. And the traditional Alexander religion (more important to people back then than today) was Protestant/Presbyterian, while Ireland was mainly Catholic. The Scots had simply recently migrated to Ireland primarily because of Plantations: http://en.wikipedia.org/wiki/Plantation_of_Ulster
The crux is the Catholics of Ireland did not want to be a part of Great Britain. And they caused a lot of trouble for the king. In about 1600, the monarch died and the next in line was the guy who was James VI of Scotland. He was promoted to King of Britain including Ireland and Scotland, now known as James I. He knew Scots were a lot tougher than the Irish. So he devised a plan to take land from the Irish (he outlawed practicing Catholicism, the penalty for which was forfeiture of all property, which causes the Irish to basically starve). He gave the confiscated lands to some rich buddies who divided up the land and sold the parcels to the poorer Scots. They came over from Scotland because the land available for crops on a per capita basis had declined as population increased.
This of course lasted until James I died and his replacement started persecuting Protestants (Scots). Coincidentally, the British colonies were recruiting immigrants, and one of the incentives was an assurance of freedom of religion. Those recently transplanted Scots who were now in Ireland and not much liking it, jumped at the chance to start anew in the new world. “Scots Irish” is the term we use.
If you want to go back before Scotland, look at your Haplogroup. http://en.wikipedia.org/wiki/Haplogroup_R1b_(Y-DNA)
The crux here is that the R1b branch of family tree of all humans was born about 15,000 to 20,000 years ago. Before that, “humans” populated Europe, having left Africa for it about 45,000 years ago. So about 20,000 years ago it started getting colder for some reason and the Last Glacial Maximum started moving south in Europe forcing man to migrate south to the northern coast of the Mediterranean. Those populations were isolated from one another for say 5,000 years. Via what is called Genetic Drift, the “average” DNA of and isolated population became much different from the other isolated populations.
The ones stuck in France/Spain migrated northward as the ice melted following the Atlantic coast for livelihood. This migration took a few thousand years so we are not talking about high-speed here. By the time they got to the NW coast of France, there was still a lot of ocean water tied up in the glacier such that there was a land-bridge across the English Channel enabling them to keep walking northward. Scotland was as far as they could go, though as you can see from the map on the wiki page, a number sailed on to Iceland.
Nothing here I have written is meant to be precise. The story is basically accurate. I simply chose to be succinct and hopefully understandable. I think it is a fascinating story. I only know of it because of DNA testing.
FYI, there is an ongoing project called https://genographic.nationalgeographic.com/
Like me, you might want to keep track of it.