切割工具演变

The diagrams illustrate the evolution of Stone Age cutting tools, comparing two devices from 1.4 million and 0.8 million years ago through front, side and back views, with a 5cm scale reference for size. Overall, while the two tools shared a similar maximum length of roughly 5cm, the later cutting implement (Tool B) showed significant improvements in shape regularity, symmetry and sharpness compared to the earlier version (Tool A), indicating technological progress in tool making over the 600,000-year period. Tool A, dating back 1.4 million years, had a rough, irregular form: its front view showed a lumpy, uneven stone with jagged, unrefined edges, its side profile was relatively thick and asymmetrical, and its back view also had irregular protrusions and rough surfaces, with a poorly defined tip. In contrast, Tool B from 0.8 million years ago was far more refined. It had a regular, teardrop shape, tapering smoothly to a sharp, pointed tip. Its side view revealed a much slimmer, more evenly balanced profile, while both front and back surfaces were smoother with more consistently chiselled edges, making it a more effective cutting device.