Early stone tools mark a pivotal moment in human evolution. The Oldowan industry, with its simple core-and-flake technology, represents our ancestors' first foray into tool-making. These basic tools allowed early humans to access new food sources and adapt to diverse environments.

The Acheulean industry that followed brought significant advancements. With more sophisticated tools like handaxes, it showcased improved cognitive abilities and craftsmanship. This leap in technology likely played a crucial role in brain development, social learning, and geographic expansion of early humans.

Oldowan Industry Features

Simple Core-and-Flake Technology

• Oldowan tools characterized by simple, core-and-flake technology primarily consisting of choppers, scrapers, and flakes
  • Choppers: simple stone tools with a sharp edge created by removing flakes from one side of a stone core
  • Scrapers: flake tools with a steep, retouched edge used for scraping and cutting
  • Flakes: sharp, thin pieces of stone detached from a core, often used as cutting tools

Percussion Flaking Technique and Raw Materials

• Oldowan toolmakers, likely early Homo species (Homo habilis), used percussion flaking technique striking one stone (hammerstone) against another (core) to remove flakes and shape the tool
• Raw materials used in Oldowan tool production were primarily locally available stones (quartz, quartzite, volcanic rocks)
• Oldowan tools used for a variety of tasks including butchering animals, processing plant materials, and possibly woodworking

Oldowan vs Acheulean Innovations

Advanced Tool Types and Craftsmanship

• Acheulean industry represents significant advancement in stone tool technology compared to earlier Oldowan industry
• Acheulean tools characterized by the appearance of large, bifacially worked handaxes and cleavers demonstrating a higher level of craftsmanship and standardization than Oldowan tools
  • Handaxes: large, teardrop-shaped tools with a pointed end and a rounded base, worked on both sides (bifacially) to create a symmetrical shape
  • Cleavers: large, bifacially worked tools with a wide, straight cutting edge at one end, resembling a modern-day cleaver

Improved Flaking Techniques and Raw Material Selection

• Acheulean toolmakers (Homo erectus) employed more advanced flaking techniques including soft-hammer percussion and platform preparation to achieve greater control over the shape and size of the tools
• Acheulean industry saw an expansion in the range of raw materials used, including the use of higher-quality stones (flint, chert) sometimes transported over longer distances
• Acheulean tools were more versatile and efficient than Oldowan tools allowing for a wider range of tasks (butchering larger animals, processing greater variety of plant foods, possibly woodworking and digging)

Cognitive Skills for Toolmaking

Oldowan Cognitive and Motor Requirements

• Oldowan tool production required understanding of properties of different raw materials, ability to select appropriate stones for tool-making, and motor skills to accurately strike hammerstone against core to remove flakes

Acheulean Cognitive Advancements

• Acheulean tool production demanded higher levels of cognitive abilities:
  • Planning and foresight to select and transport suitable raw materials
  • Mental templates for the desired shape and size of the tools
  • Ability to maintain attention and focus during the lengthy process of shaping a handaxe or cleaver
• Acheulean toolmakers also needed more advanced motor skills:
  • Hand-eye coordination to accurately strike the stone and remove flakes
  • Manual dexterity to hold and manipulate the stone core while flaking
  • Ability to apply controlled force and precision to shape the tool symmetrically

Implications for Hominin Brain Evolution

• Increased cognitive and motor skills associated with Acheulean tool production may reflect evolutionary changes in hominin brain size and structure, particularly in areas related to planning, problem-solving, and fine motor control

Stone Tool Implications for Evolution

Dietary Changes and Brain Growth

• Development of stone tools allowed hominins to access new food resources, particularly animal protein from scavenging and hunting, which may have contributed to brain growth and changes in gut morphology
• Use of tools for processing plant materials (tubers, nuts) expanded the range of available food resources providing a more stable and diverse diet that could support larger group sizes and longer life spans

Social Learning and Cultural Transmission

• Production and use of stone tools likely facilitated the development of social learning and cultural transmission as knowledge and skills related to tool-making were passed down through generations
• Cognitive demands of tool production, particularly in Acheulean industry, may have driven the evolution of increased brain size and complexity in hominins setting the stage for the emergence of later species (Homo sapiens)

Geographic Expansion and Adaptation

• Expansion of hominin geographic ranges, particularly with the spread of Homo erectus, may have been facilitated by the versatility and efficiency of Acheulean tools which allowed for adaptation to diverse environments and resources
• Oldowan and Acheulean industries demonstrate increasing technological and cognitive capabilities of early hominins marking important milestones in the long history of human evolution and cultural development