Effects of different environmental factors on preservation of DNA in petrous bones: A comparative study of two Slovenian archaeological sites

DNA preservation is influenced by various external and internal factors that are complexly intertwined. Environmental factors are among the variables that have the most significant impact on preserving genetic material. To better understand their effects, 247 petrous bones from two geographically distinct cemeteries were compared. Molecular genetic methods were used in the study, including a complete demineralization extraction method to obtain the DNA from bone samples and real-time PCR to determine DNA quantity and quality. Statistical analysis was performed to investigate the differences in DNA yield and DNA degradation between petrous bones from the two different Slovenian archeological sites, Ljubljana - Njegoševa and Črnomelj. Results showed significantly higher DNA yield and lower degradation index in petrous bones from the Ljubljana - Njegoševa cemetery. The differences emphasize the impact of environmental factors, especially that of temperature, pH and permeability of the soil, on DNA degradation. This study provides valuable insights into understanding the complexity of DNA preservation in skeletal remains from different types of environments.