Several questions are embedded within the short film The Making of the Fittest: Got Lactase? The Co-evolution of Genes and Culture, which explores the genetics of lactase persistence and evolution of the trait in some human populations.

Babies can easily digest milk, the food especially provided for them by their mothers. Later in life, most of us lose this ability because we stop producing lactase, the enzyme that helps us digest the sugar in milk. But about one-third of adults worldwide continue to produce the enzyme, a phenomenon known as lactase persistence. This film explores the genetics behind lactase persistence and discusses research that traces the origin of this trait to less than 10,000 years ago. The origin of lactase persistence coincides with a cultural shift in human populations who began to use the milk of other mammals as food. Combining genetics, chemistry, and anthropology, this story provides a compelling example of the co-evolution of human gene regulation and human culture.

This version of the film with embedded questions contains automatic pause points, during which students answer questions about the film to assess their understanding of the concepts presented. After answering all the questions, students can view and print their answers.