This article provides two activities, exploring genetic drift of small breeding populations, highlighting the black-footed ferret ("Mustela nigripes"). According to the U.S. Fish and Wildlife service, all black-footed ferrets are descended from 18 individuals, making them extremely vulnerable to genetic drift. They were thought to be extinct until the 1970s and 80s, due to population expansion in the western United States. Activity 1 uses a conceptual computer model to explore fixation and loss in black-footed ferrets. Activity 2 uses a mathematical model in an Excel spreadsheet to examine genetic drift of allele frequencies by varying the initial population number of black-footed ferrets and other nearly-extinct species. These activities offer students the opportunity to construct an explanation of evolution based on evidence and address the pressing need to use data to inform environmental policy for biodiversity protection.