What did scientists believe about early hominids before the discovery of Lucy?

Before the discovery of Lucy in 1974, scientists primarily believed that early hominids were more similar to modern humans and that they evolved from a linear progression of species. The prevailing theories suggested that hominids were primarily tool users and had larger brain sizes compared to earlier primates. Lucy's discovery, however, revealed that early hominids like Australopithecus afarensis exhibited a mix of both ape-like and human-like traits, challenging previous notions about the complexity and diversity of hominid evolution. This finding underscored the idea that human evolution was not a straightforward path but rather a branching tree with various adaptations.