Final answer:
Bipedalism preceded other hominid traits such as increased brain size, tool use, symbolic thought, and language, with anatomical evidence showing early hominin species already adapted to walking on two feet.
Step-by-step explanation:
Among the traits listed, E) bipedalism appears to have emerged before the others. The evolution of hominin bipedalism required a complex anatomical reorganization which provided several advantages such as freeing the hands for tool use and improving thermoregulation. This development precedes the likes of tool use, increased brain size, symbolic thought, and language.
For instance, evidence suggests that Homo habilis, an early hominin species, was already bipedal, with adaptations present in the hip structure supporting bipedalism. After the development of bipedalism, hominins such as Homo habilis and Homo erectus witnessed increases in brain size, and cognitive abilities, and eventually, began using and creating stone tools. Finally, these cognitive developments laid the foundation for complex communication, giving rise to symbolic thought and language. Consequently, E) bipedalism is the trait that seems to have occurred earlier than the others such as tool use, increased brain size, symbolic thought, and language.