Final answer:
The term that describes what occurs when genetic drift results in the formation of a new population that has less genetic variation than the original population had is called the founder effect.
Step-by-step explanation:
The term that describes what occurs when genetic drift results in the formation of a new population that has less genetic variation than the original population had is called founder effect. The founder effect occurs when a small group of individuals migrates or becomes separated from a larger population, resulting in a new population with a limited genetic diversity. This can lead to a higher incidence of certain genetic disorders, as seen in the example of the Afrikaner population in South Africa.