That is far more than could be explained by spontaneous mutations, which suggests the malfunctioning genes are doing some good.

ECONOMIST: Cleft palate and herpes

The team was particularly interested in spontaneous mutations: Those that are not present in either parent, so must arise spontaneously in the sperm, egg, or in the embryo.

FORBES: Parental Age, Especially The Father's, Is Linked To Genetic Mutations In The Child

At least 10% of childhood heart defects are tied to spontaneous genetic mutations, a study said.

WSJ: What's News