How was Homo erectus different from earlier human ancestors in two ways?

Homo erectus was different from earlier human ancestors in several key ways, but two of the most significant differences are as follows:

1. Physical Stature and Bipedsalism: Homo erectus was generally taller and had longer legs compared to earlier hominins like Australopithecus. This change in body proportion suggests that Homo erectus was more efficient at walking and running over longer distances. Their skeletons show evidence of an adaptation to a life lived on the ground rather than in the trees, which is a significant shift from earlier ancestors who exhibited more adaptations for climbing.

2. Brain Size and Complexity: Homo erectus had a larger brain than their predecessors, with an average brain size of about 900 cubic centimeters, which is about 68% of the size of the modern human brain. This increase in brain volume indicates a greater capacity for complex thought and behavior. This change is associated with evidence of more advanced tool use and technology, suggesting that Homo erectus had increased intellectual capabilities.