human evolution Refinements in tool design

In Africa the Early Paleolithic (2.5–0.2 mya) comprises several industries with the earliest man-made chipped flakes and core choppers (2.5–2.1 mya). Double-faced hand axes, cleavers, and picks (collectively known as bifaces) appeared about 1.5 mya and persisted until 200 kya. Archaeologists have detected some improvements of technique and product during the half-million-year span of core-flake industries. Although the major biface industry—the Acheulean—has been characterized as basically static, it too shows evidence of refinement over time, finally resulting in elegant, symmetrical hand axes that required notable skill to make.

By 1.7 mya a population of H. erectus similar to African H. ergaster lived in Eurasia at what is now Dmanisi, Georgia. The associated choppers, chopping tools, flakes, and scrapers recall the Oldowan core-flake industry of eastern Africa, but there are no bifaces among them. The braincase of the two Dmanisi specimens is smaller than that of African H. ergaster. New geochemical dates for classic hominin localities in Java indicate that H. erectus may have lived in Southeast Asia 1.5 mya, but no industry is certainly identified with them.

El ʿUbeidīya, Israel, provides evidence that people and bifaces had spread out of Africa by 1.4 mya. In Europe, Acheulean tools appear 500 kya and persist until about 250–150 kya; they also occur in South Asia. Sites in China (800 kya), Korea, and Japan contain bifaces, but they differ from Acheulean tools. No such technology has been found in tropical Southeast Asia, where bamboo tools may have sufficed.

In both Africa and Eurasia, where the Middle Paleolithic lasted from 200 to 30 kya, tools are characterized by carefully prepared cores from which elegant flakes were struck. There are many local and regional variations in size, shape, and frequencies of reshaped flakes, blades, scrapers, hand axes, and other tools. Projectile points began to be emphasized in some regions, with bone being used as well as stone; bone arrow points dating to more than 60,000 years ago have been found at Sibudu Cave in South Africa.

Late Paleolithic industries dating to 50–10 kya comprise diverse blade and microblade tools, especially in Europe. Late Paleolithic peoples used a variety of materials for their tools and bodily ornaments, including bone, stone, wood, antler, ivory, and shell. Stone blades were long, thin, and very effective cutting tools. Often, when they became dull, someone retouched them via pressure flaking, which requires fine motor control and coordination. Microblades and other points were probably hafted to produce throwing and stabbing spears. Other composite tools of the period include atlatls, harpoons, fish weirs, and bows and arrows. Late Paleolithic people also developed techniques for grinding and polishing, with which they made beads, pendants, and other artistic objects. They also made needles (perhaps for sewing fitted clothing), fish hooks, and fish gorges.