In this activity, students examine concepts about the evolution of human bipedality explored in the short film Great Transitions: The Origin of Humans. They create their own trackway of footprints and compare it to a trackway of fossil footprints.

A 3.6-million-year-old trackway of footprints was discovered at the Laetoli site in Tanzania in 1976. Fossils of the hominid species Australopithecus afarensis were found near the Laetoli footprints. Since A. afarensis was the only hominid species known to be living in the area at the time, it is assumed that the footprints at Laetoli were made by A. afarensis.

By studying footprints made during class using paint, students explore what footprints reveal about our human ancestors in this three-part activity, through observations, analysis, and evaluation. Students draw inferences from an illustration of the Laetoli trackway, compare their own footprints to those at Laetoli, and evaluate the evidence that the Laetoli footprints were made by a fully bipedal human ancestor. The activity ends with a summary activity in which students compare chimpanzee and human footprints. This last section can be completed as homework.