Assessing Ancient DNA Damage Patterns Across Different Climate Regions

Authors: Eric Hauptman, Matthew Emery

Field of Study: Anthropology

Faculty Mentors: Matthew Emery

Easel: 23

Timeslot: Midday

Abstract: Ancient DNA degradation has traditionally been interpreted primarily as a function of time. More recent research, however, has shifted attention toward the burial environment, identifying climate as a major determinant of DNA preservation. Heat, moisture, and microbial activity accelerate molecular decay, creating a systematic bias in genomic datasets where cold-climate populations are overrepresented and tropical populations underrepresented. To quantify these effects, publicly available mitochondrial DNA samples (n=41) from approximately 5,000 to 7,000 years BP across five Köppen-Geiger climate zones were analyzed. These DNA damage results indicate that DNA obtained from warm and arid regions shows substantially higher levels of cytosine deamination and shorter mean fragment lengths than arctic or continental zones, with damage accumulating toward the terminal ends of molecules at 2-3 times the rate. Recognizing these preservation gradients is essential for identifying optimal sampling environments and informing mitigation strategies for the most poorly preserved regions.