Humidity as a source of measurement error in osteometrics

Area of Science:

• Osteology
• Biological Anthropology
• Forensic Science

Background:

• Dried, preserved bone specimens are susceptible to environmental changes.
• Humidity variations can potentially influence the physical dimensions of skeletal material.
• Accurate osteometric measurements are crucial for various scientific disciplines.

Purpose of the Study:

• To investigate the effect of humidity on the dimensions of dried, preserved macaque skulls.
• To determine if humidity variation causes measurable bone expansion.
• To assess the impact of such changes on osteometric data.

Main Methods:

• Ten macaque skulls were subjected to a controlled high-humidity environment for 24 hours.
• Nine standard skull dimensions were measured before and immediately after humidification.
• Statistical analysis was performed to identify significant changes in dimensions.

Main Results:

• A statistically significant increase in skull dimensions was observed with increased humidity.
• The molar tooth row length increased by approximately 0.50% (0.1 mm).
• The greatest skull length increased by approximately 0.57% (0.9 mm).
• Specimens reverted to original dimensions within 1-2 days post-exposure.

Conclusions:

• Humidity variation demonstrably causes minor, reversible expansion in preserved bone.
• These bony changes represent a real, albeit small, source of measurement error in osteometrics.
• Findings support practical observations of dimensional variability in museum specimens across different environments.