stya wrote:I can really see it happen quickly in small villages and reduce dramatically your numbers... Towns/villages used to be very small in comparison to what we have these days.
This is the key to solving the problem. With airline travel, people have really spread out as families go to other places for jobs. It's why Swedes look different than the Swiss, why almost all of Ireland is red-headed. Even with larger cities such as London, Rome, Paris, Berlin, you only go back so many generations before you family tree quits forking in a binary manner. You get into rural communities where there are just a few hundred people at best, and it probably didn't get past 3 before it became entangled. (let's not even mention the royalty of Europe... there's a reason they called each other "cousin" as a casual greeting, and it wasn't because they were speaking to each other as peers.)
I had an aunt that did a genealogy of the family back before the Internet and sites like ancestry.com. I was really surprised at some of what I saw. I can tell you that, mathematically, it's almost guaranteed that, somewhere in the past, your family is inbred to some degree. I don't care who you are. If you're family claims any sort of nobility or royalty in the past, it is a guarantee.