Interesting question, Mr. Wallace.   Sadly, I’m even less of a mathematics or genetics expert than you are (no science nor math requirements at the G. U. Foreign Service School).  Knowing you love good fiction, I can tell you, however, that one of the twins in Wally Lamb’s I Know This Much Is True was, like my brother, born in December 1949, while his brother was born in January 1950. 

Interesting question, Mr. Wallace.   Sadly, I’m even less of a mathematics or genetics expert than you are (no science nor math requirements at the G. U. Foreign Service School).  Knowing you love good fiction, I can tell you, however, that one of the twins in Wally Lamb’s I Know This Much Is True was, like my brother, born in December 1949, while his brother was born in January 1950. 

Now, I’m just a simple English-major-turned-lawyer, so I never had to wrestle with the higher mathematics or the intricacies of reproductive genetics, but it seems to me that in my vast reading of “weblogs” I have seen somewhere or other — maybe there’s a semi-reliable entry on Wikipedia? — that “twins” are commonly born on more or less the same day as one another. Am I reclling that correctly, David? Hmmmm?

Now, I’m just a simple English-major-turned-lawyer, so I never had to wrestle with the higher mathematics or the intricacies of reproductive genetics, but it seems to me that in my vast reading of “weblogs” I have seen somewhere or other — maybe there’s a semi-reliable entry on Wikipedia? — that “twins” are commonly born on more or less the same day as one another. Am I reclling that correctly, David? Hmmmm?