Which hypothesis states that primates adapted to life in the trees?

The hypothesis that states that primates adapted to life in the trees is known as the Arboreal hypothesis. This theory suggests that the unique characteristics of primates—such as grasping hands and feet, flexible limb structures, and enhanced vision—evolved as adaptations to a life spent in the arboreal environment. The rationale is that these traits enabled primates to navigate the complex three-dimensional environment of trees more effectively, thereby aiding in locomotion, foraging, and avoiding predators.

The Arboreal hypothesis highlights the importance of tree-dwelling as a fundamental aspect of primate evolution, emphasizing the selection pressures that living in trees would impose. For instance, the need for better depth perception and hand-eye coordination in a three-dimensional space would favor the development of traits that are characteristic of primates today. This adaptation for arboreal living is seen as crucial for understanding why and how primates, including humans, evolved their distinct traits.