A newborn baby cannot walk, feed itself or even lift its head. Compared with most animals, human babies are remarkably helpless. Yet this dependence is not a weakness; it is an evolutionary advantage.

Ms. Renkl is a contributing Opinion writer who covers flora, fauna, politics and culture in the American South. Every year as I’m unpacking my grandmother’s nativity set, I hide the ceramic baby in a ...

Every year as I’m unpacking my grandmother’s nativity set, I hide the ceramic baby in a drawer. My grandmother installed the baby in the manger on the first day of Advent, but it’s a tradition in this ...