To explain how new variants originate, de Vries developed a mutation theory that led to a temporary rift between those who accepted Darwinian evolution and biometricians who allied with de Vries.
Mangda prasida nlatarang indik varian anyar, de Vries nglimbakang teori mutasi sané ngawinang pamargin nénten becik pantaraning sané nrima evolusi Darwin miwah sujana biometrik sané makanti sareng de Vries.