Establish Prior Knowledge
Have students share what they know about ancient human migration. If necessary, direct them to this website to view an animation of how early migration occurred (click 10,000 B.C. to see the complete migration).
Point out that the information on this migration map is based on mitochondrial DNA, which is passed down each generation from mother to child. Mitochondrial DNA can identify a person’s direct ancestry (maternal ancestry).
Tell students that in the snapshot they are about to see scientists investigate human migration by analyzing the DNA of a stomach bacteria that, oddly enough, has evolved with us.
Have students view the Snapshot and read the synopsis. Use the following questions to guide your discussion:
- What is Helicobacter pylori?
- What happened to the stomach bacteria as human populations migrated and changed genetically?
- What did the study of Helicobacter pylori genes reveal about the colonization of Australia and Polynesia?
Use the following question to wrap up your discussion:
- How can the study of H. pylori DNA help support or reject hypotheses about early human migration patterns?