Does the human body evolve as quickly as human culture? With a stellar 15-minute video, explore the trait of lactose intolerance. Only about 1/3 of human adults seem to still have the enzyme lactase and therefore, the ability to digest lactose. Scientists look at the DNA and the history of two cultures that might explain why. Follow the video with one of the accompanying lab activities in which biochemistry learners measure glucose changes over time after adding lactose (milk) to simulated intestinal fluid samples (lactase solution). This is a thick and creamy lesson!