Eugenics

Eugenics is the process of selectively breeding traits into or out of species. This can be achieved by various means, through successive generations by selective breeding or more immediately via genetic engineering.

Eugenics via genetic engineering to sentient lifeforms in banded in the United Federation of Planets following Earth’s Eugenics Wars in the late 20th century, when genetically augmented humans ruled and warred over the planet. (DS9 episode: Doctor Bashir, I Presume?; TOS episode: Space Seed; et al.)

In 2254 when the lost colony of violent emotional Vulcan's was discovered Spock described there effect on returning to Vulcan as being comparable to his Human Cpatain Christopher Pike discovering a lost colony of Khan Noonien Singh's (an augment from Earth's Eugenics Wars) Eugenics warriors (EV comic: Cloak and Dagger). Years later Spock then serving under Captain James T. Kirk did just that finding Kahn and a group of his followers on the SS Botany Bay (TOS episode: Space Seed).