The onset of pregnancy presents an apparent contradiction. Ovulating and initially pregnant mothers experience an increase in progesterone. On the one hand, this hormone signals the immune system to back down and lay low. That's critical, because otherwise her body would fight and kill sperm cells as though they were unwelcome invaders, and she would never become pregnant.

In short, no way. But Christians should understand the biblical and biological reasons why not. Then we can have a meaningful conversation with friends and family, made more relevant by the theatrical re-releases of 3-D versions of the Jurassic Park films that imagine cloned dinosaurs.