Innovation, life history and social networks in human evolution

Area of Science:

• Paleoanthropology
• Evolutionary Anthropology
• Archaeology

Background:

• The archaeological record reveals a slow pace of technological change in early human history, particularly during the Acheulian period.
• Understanding the reasons behind this technological stasis is crucial for reconstructing early hominin social behavior and cognitive evolution.

Purpose of the Study:

• To explain the prolonged stasis observed in early human technological history.
• To propose a model based on inferred life history and social network characteristics of earlier human species.

Main Methods:

• Inferred phylogenetic characteristics of earlier human species.
• Analysis of archaeological evidence for technological persistence (e.g., Acheulian handaxes).
• Comparative analysis with great ape social structures, particularly chimpanzees and bonobos.

Main Results:

• Archaeological traces primarily reflect widespread and persistent technologies, not the rate of innovation.
• Innovations are vulnerable to loss before widespread adoption.
• Intergroup hostility or limited contact restricts the spread of new technologies.
• Male philopatry and subadult female dispersal, common in great apes, likely characterized early hominins, creating significant filters for innovation spread.

Conclusions:

• The slow pace of technological change in early human history can be explained by social and life history factors.
• Innovation spread was heavily constrained by limited intergroup contact and the specific dispersal patterns of females.
• Only innovations acquired and expressed by dispersing females had a high likelihood of becoming widespread.