HJ.T. Bijlmer's 1943 article in the journal Genetica switched on a lightbulb in Mannis van Oven's head that pointed toward Nias, an island off Sumatra's western coast. The molecular biology researcher from the Netherlands was amazed to learn that most Nias people were blood type O. Also the people of Nias seemed to have distinctive features compared with other Southeast Asian ethnic groups.

Van Oven's mind was running wild. The 30-year-old suspected t