Final answer:
The forest model suggesting that bipedalism evolved as a response to hominins leaving forests for savannas is false.
Step-by-step explanation:
The statement that the forest model suggests bipedalism evolved as a response to the ancestors of hominins leaving the forests to explore the savannas is false. In fact, this statement refers to the savanna hypothesis, which suggests that many human traits, such as upright bipedalism, evolved as adaptations to a savanna habitat. This hypothesis posits that as our ancestors moved from forested areas into open savanna environments, bipedal locomotion provided numerous advantages, such as the ability to travel efficiently over long distances, spot predators over tall grass, and free hands for carrying objects and using tools.
Anatomical changes necessary for bipedalism, like a broader pelvis, longer legs, and arched feet, evolved over time, beginning with species like Australopithecus, and becoming nearly as efficient as in modern humans with the advent of Homo erectus around 2.8 million years ago. The evidence of early hominin bipedalism includes the famous 3.5-million-year-old Laetoli footprints, discovered by Mary Leakey, indicating a modern striding gait among Australopithecus afarensis.