I know the study you are talking about and there was another one on triplets. These 3 women were so close in all they did in life and it was strange how they all got married and had children around the same time. However, they did do a DNA test to see if it could reveal anything that would link why they did everything together. In the end, it proved that one of the girls had completely different DNA than the other two. I have some idea what my DNA might prove and I guess it would be fun to see if it was what I think it is. My grandmother is American Indian, she married a man who migrated from Russia in 1891 when he was just 13 years old. Now his history is a bit of a mystery because he was born in Russia after a war the border was moved and now he lived in Poland. This happened several times until his dad was killed in one of the wars and his mom put him on a boat to New York. Now the question is this, what he Polish or was he Russian? This would be interesting to find out. The same about my dad and his side of the family. I know how he ended up in France and I know that his great-grandparents were from Scotland and Ireland and migrated to France. But what is the real story behind all this? It might be fun to find out.