Cumulative human culture began ~600,000 years ago, during the Middle Pleistocene

An interesting study by Paige and Perreault:  

Significance

Our species, Homo sapiens, occupies a uniquely diverse set of ecological habitats. Humans expanded into tropical forests and arctic tundra through cumulative culture. Cumulative culture is the accumulation of modifications, innovations, and improvements over generations through social learning. Generations of variant accumulations allow humans to use technologies and know-how well beyond what a single naive individual could invent independently within their lifetime. We analyzed the stone tools made during the last 3.3 My. We found that these stone tools remained simple until about 600,000 B.P. After that point, stone tools rapidly increased in complexity. Consistent with findings from other research teams, we suggest that this transition signals the development of cumulative culture in the human lineage.

Cumulative culture, the accumulation of modifications, innovations, and improvements over generations through social learning, is a key determinant of the behavioral diversity across Homo sapiens populations and their ability to adapt to varied ecological habitats. Generations of improvements, modifications, and lucky errors allow humans to use technologies and know-how well beyond what a single naive individual could invent independently within their lifetime. The human dependence on cumulative culture may have shaped the evolution of biological and behavioral traits in the hominin lineage, including brain size, body size, life history, sociality, subsistence, and ecological niche expansion. Yet, we do not know when, in the human career, our ancestors began to depend on cumulative culture. Here, we show that hominins likely relied on a derived form of cumulative culture by at least ~600 kya, a result in line with a growing body of existing evidence. We analyzed the complexity of stone tool manufacturing sequences over the last 3.3 My of the archaeological record. We then compare these to the achievable complexity without cumulative culture, which we estimate using nonhuman primate technologies and stone tool manufacturing experiments. We find that archaeological technologies become significantly more complex than expected in the absence of cumulative culture only after ~600 kya.