Which hypothesis suggests that primates' traits arose from adaptations to life in trees?

The arboreal hypothesis suggests that the traits seen in primates evolved as adaptations to living in trees. This hypothesis is based on the idea that the challenges of navigating a three-dimensional environment, such as jumping, climbing, and grasping branches, would favor certain physical and sensory adaptations. These include enhanced vision, flexible limbs, and opposable digits, which together would enable primates to thrive in arboreal habitats.

Both the visual predation and angiosperm radiation hypotheses also explore adaptations in primates but focus on different aspects. The visual predation hypothesis emphasizes adaptations that arose from hunting insects and small animals, while the angiosperm radiation hypothesis posits that the diversification of flowering plants (angiosperms) created new food sources like fruits, influencing primate evolution. Lastly, the haplorhine hypothesis relates specifically to the classification and evolutionary relationships within primates but does not specifically address tree-dwelling adaptations. Thus, the arboreal hypothesis is the most directly concerned with the adaptations necessary for life in trees.