Students use uniprot to compare the amino acid sequences of caffeine synthase, which is a protein that produces caffeine in tea, coco, and coffee plants. The sequence reveals that the sequences are not very similar. Students then read and abstract from a science journal and analyze a phylogenetic tree showing the common ancestors of these plants.
The activity uses a 5E lesson plan (engage, explain, explore, elaborate, evaluate) though it is largely self paced. Students can do it as homework.
This worksheet is available for free at https://www.biologycorner.com/worksheets/evolution-caffeine.html