Final answer:
The two major controversies for which hominin bipedality evolved are the Savanna hypothesis and the wooded grassland model.
Step-by-step explanation:
The two major controversies for which hominin bipedality evolved are the Savanna hypothesis and the wooded grassland model. The Savanna hypothesis proposes that human traits, including upright bipedalism, evolved as adaptations to a savanna habitat. On the other hand, the wooded grassland model suggests that bipedality evolved in response to living in a mixture of forested and open grassland environments.