I was away over the weekend and am still catching up on my New York Times. My favorite tidbit: "Until now, it had been widely assumed by geneticists that the Ashkenazi [Jewish] communities of Northern and Central Europe were founded by men who came from the Middle East, perhaps as traders, and by the women from each local population whom they took as wives and converted to Judaism." But a new study, published online this week in the American Journal of Human Genetics, suggests that papa was not, in fact, a rolling stone -- that is, that "the men and their wives migrated to Europe together." Isn't that nice?

The research, which traced a certain type of DNA inherited only through the female line, further suggests that "just four women, who may have lived 2,000 to 3,000 years ago, are the ancestors of 40 percent of Ashkenazis alive today." (That's 8 million people. My mom is so glad she had to worry about only one.)