Why do people have extra nipples?

Extra nipples were once thought to be a link to our evolutionary past, but the truth is a lot stranger, writes Jason G Goldman.

Supernumerary Nipple: Causes, Diagnosis, and Images — DermNet

Harry Styles Confirms He Has Four Nipples, a Condition Called

Third Nipple: Incidence, Types, Causes, and Removal

Zac Efron's Extra Nipples? Skin Physicians & Surgeons

Does Harry Styles have four nipples? Why does it happen and how

Why Men Have Nipples - Experts Explain

What Does Having a Third Nipple Mean? Supernumerary Nipples - GoodRx

Third Nipple: Types, Causes, and Removal

Harry Styles Has Four Nipples and We've Got Proof

Gynecomastia Diet: Best And Worst Foods To Eat