A 5700 year-old human genome and oral microbiome from chewed birch pitch
The authors of this paper managed to extract an incredible amount of information from a 5700 year-old chewed up piece of birch pitch (a kind of tar used for a variety of things by early humans). They were able to sequence the genome of the woman who chewed on the pitch and trace her ancestry, oral microbiome, and what she had recently eaten (hazelnut, birch, and duck).