GRADUAL CHANGE IN HUMAN TOOTH SIZE IN THE LATE PLEISTOCENE AND POST-PLEISTOCENE

Area of Science:

• Paleoanthropology
• Human Evolution
• Dental Anthropology

Background:

• Human tooth size has undergone significant changes over millennia.
• Understanding these changes provides insights into human adaptation and technological advancements.

Purpose of the Study:

• To analyze the rate and patterns of human tooth size reduction over different geological periods.
• To investigate the potential environmental and cultural factors influencing dental evolution.

Main Methods:

• Comparative analysis of dental dimensions (mesial-distal and buccal-lingual) from the Late Pleistocene to the present.
• Examination of geographical variations in tooth size reduction rates across different regions.

Main Results:

• Human tooth size reduced by 1% every 2,000 years during the Late Pleistocene (100,000 to 10,000 years ago).
• The rate of dental reduction doubled to 1% per thousand years in the Post-Pleistocene era.
• Buccal-lingual dimensions are reducing twice as fast as mesial-distal dimensions, with maxillary teeth showing faster reduction than mandibular teeth.
• Similar reduction rates were observed in Europe, the Middle East, China, Japan, and Southeast Asia during the Post-Pleistocene.

Conclusions:

• Early cooking techniques during the Late Pleistocene may have initiated dental size reduction.
• The advent of pottery use in the last 10,000 years further decreased selective pressures on tooth size.
• The ongoing dental reduction is likely a consequence of the Probable Mutation Effect, where genetic mutations accumulate in the absence of strong selective pressures.