My father, upon his retirement, decided to trace the family tree. He told me that if you go back just 20 generations you have a million ancestors. I did the math and to my utter astonishment he was correct. It seemed impossible because there were easily 4 generations at the same dinner table at one time in my life, but you can't just multiply that by 5. Roots don't work that way!
For my Dad it was a labour of love with emphasis on the labour. Book after book after book, most of which are kept by the various churches of this world. They recorded the marriages, the births and the deaths of the past. It was not possible to get everything he wanted because documents were destroyed. The earth, wind and fire take a toll. Rats and mice :( take a toll. But he managed to get quite far back anyway. All the way to 1785, 1787, and 1800 to my great, great, great grand parents. Some from my mother's side of the family and some from his. He was doing it for us so he included my Mom's tree also. That gets me the names of almost all 16 great*** grands. For me that's only 6 generations, for my grandson that is 8! I am very happy that my father started down that path. I hope to keep the data string going because the record keeping has changed hands and the retrieval of this kind of information may become more difficult to obtain.
It is believed that those of us who have MS come from mostly a northern European ancestry. Also that each of us has spent the first 7 years of our lives in a temperate climate. Could it also be that we all have a common ancestor. It may only take one.