Split-Sex Animals Are Unusual, but Not as Rare as You’d Think | The New York Times

By Karen Weintraub All serious butterfly collectors remember their first gynandromorph: a butterfly with a color and pattern that are distinctly male on one wing and female on the other. Seeing one sparks wonder and curiosity. For the biologist Nipam H. Patel, the sighting offered a possible answer to a question he had been pondering