Which feature notably differentiates Homo erectus from modern humans?

Homo erectus is notably differentiated from modern humans primarily by having a smaller brain size and a more robust skeletal structure. The average cranial capacity of Homo erectus ranged between about 600 to 1,100 cubic centimeters, which is significantly smaller than the average modern human brain size, typically around 1,300 to 1,500 cubic centimeters. This difference in brain size is indicative of varying cognitive abilities and complexity.

Additionally, Homo erectus possessed a more robust and sturdy skeletal structure, adapted for the physical demands of their environment. These features suggest a lifestyle that was different from that of modern humans, who tend to have a lighter, more gracile build. The robust nature of Homo erectus reflects their adaptation to their specific ecological niche and the challenges of their time, which included both predator avoidance and mobility.

Advanced language ability and social complexity, greater tool-making diversity and artistry, as well as larger eye sockets and shorter limbs, do not primarily differentiate Homo erectus from modern humans in the same way. While tool-making capabilities and social structures did evolve over time, the most prominent and immediate difference is in the physical attributes, particularly brain size and skeletal robustness.