West African Monkey Foot Flexibility Challenges Human‑Chimp Ancestor Model

A new study of wild monkeys in West Africa shows they can climb vertical tree trunks using a previously unrecognized foot flexibility. The finding contradicts a long‑held assumption that the last common ancestor of humans and chimpanzees had limited foot mobility. Researchers noted that the monkeys’ ability to grasp and maneuver on steep surfaces suggests that early hominins may have possessed greater foot dexterity than fossil evidence has implied. The discovery calls into question prevailing reconstructions of the ancestor’s appearance and locomotor behavior, urging a re‑examination of how we interpret early primate fossils.