The fossil record suggests that around 600,000 years ago, there was a significant leap in stone tool complexity that changed the course of human evolution. The University of Missouri anthropologist Jonathan Paige and Arizona State University anthropologist Charles Perreault have conducted a study that sheds light on how this sudden increase in knowledge led to the development of modern humans and their ancestors’ adeptness at adapting to new environments.
Paige and Perreault analyzed stone tool manufacturing techniques over a span of 3.3 million years of human evolution. They examined 62 tool-making sequences from 57 sites and ranked them according to their complexity. The research revealed that before 1.8 million years ago, stone tool manufacture sequences typically ranged from two to four procedural units. However, over the next 1.2 million years, there was a gradual increase in tool complexity, with some sequences reaching up to seven procedural units.
Around 600,000 years ago, a significant shift occurred in hominin knowledge, as tool complexity escalated to requiring up to 18 procedural units. This advancement in technology was made possible by the accumulation of knowledge passed down through generations, known as cumulative culture. This process involves the incorporation of modifications, innovations, and improvements over time through social learning.
Paige and Perreault describe cumulative culture as the outcome of generations of trial and error, leading to the development of technologies that surpass what any individual could invent within their lifetime. This collective knowledge and the associated behaviors have been crucial in the evolution of human intelligence, as it allows for the continual advancement and adaptation of skills and technologies.
Cumulative culture not only enhances problem-solving abilities through generations of experimentation, similar to how evolution operates through natural selection, but it also enables individuals to build upon existing knowledge without fully comprehending the entire developmental process. As a result, there is a constant expansion of knowledge and the evolution of behaviors.
The researchers suggest that genes related to learning may have been selected for in response to the development of cumulative culture. This gene-culture coevolution process could have contributed to an increase in relative brain size, a prolonged life history, and other key traits that distinguish humans from other species.
While the findings of Paige and Perreault indicate the presence of cumulative culture during the Middle Pleistocene, the researchers acknowledge that this cultural intelligence may have emerged even earlier in human history in ways that are not easily preserved in the archaeological record. It is possible that early hominins relied on cumulative culture to develop complex social, foraging, and technological behaviors that are not readily apparent through archaeological evidence.
Regardless of the specifics of the technology or the exact timing of its development, the reliance on cumulative culture has likely been a significant driving force in shaping many of the unique features of humanity. This evolutionary process has played a crucial role in the advancement of human knowledge and intelligence, leading to the complex societies and technologies that define modern humans.