Studying population history and the evolution of the human oral microbiome through ancient chewing gums
Name of applicant
Hannes Schroeder
Institution
University of Copenhagen
Amount
DKK 4,495,997
Year
2019
Type of grant
Semper Ardens: Accelerate
What?
Our ability to recover ancient DNA from archaeological bones and teeth has revolutionised our understanding of human prehistory, but there are still important gaps in our knowledge. In this project, we will explore the potential of ancient pieces of chewed birch pitch as an alternative source of ancient DNA. Birch pitch was commonly used in prehistory for hafting stone tools and pieces of birch pitch are often found with tooth imprints suggesting that they were chewed. Over the course of this project, we will analyze over 300 birch pitch specimens from Scandinavia and beyond using ancient genomics and proteomics methods in order to shed new light on the population history of prehistoric Europe and the evolution of the human oral microbiome.
Why?
Previous research by my group has shown that chewed pieces of ancient birch pitch provide an excellent source of ancient DNA. In the process of chewing, the DNA becomes trapped in the pitch where it is preserved thanks to the resin’s antibacterial and hydrophobic properties. The DNA offers a real snapshot of prehistoric people's lives, providing information on their genetic ancestry, physical appearance, and - through the DNA of food items - even their diet. In addition, the microbial DNA provides information on people’s health status, the composition of their oral microbiome, and the evolution of specific human pathogens. The results of this research will fill important gaps in the population history of Europe and it will yield some of the oldest human microbiomes sequenced to date.
How?
Over the course of the project, we will analyze over 300 ancient pieces of chewed birch pitch from different Stone Age sites in Scandinavia and continental Europe. We will analyze the specimens using a combination of genomics and mass spectrometry-based proteomics methods. The data will be analyzed using bioinformatic pipelines to facilitate: The reconstruction of complete or partial ancient human genomes. The taxonomic profiling of metagenomic reads. The characterisation of the protein component. The human data will be used for population genetic analyses, while the microbial data will be used to reconstruct the composition of the oral microbiome and to study the evolution of specific pathogens.