‘Tis the season for twinkling lights, wrapping paper, and virgin birth. For billions of Christians around the world, the holidays are a time to celebrate Jesus’s birth to the Virgin Mary. But for many animals, virgin birth is far from a miraculous event. Researchers have discovered a growing number of species that reproduce without assistance from the opposite sex. Known formally as parthenogenesis, virgin birth occurs when an embryo develops from an unfertilized egg cell. The development of an embryo usually requires genetic material from sperm and egg, as well as a series of chemical changes sparked by fertilization. In...