The Birch pitch found in southern Denmark

A complete ancient human genome and oral microbiome sequenced from a 5700 year-old piece of chewed birch pitch is found from Denmark.

A Birch pitch is a part of birch tree which is used a chewing gum in ancient days.

Radio-carbon dating indicated a direct date of 5,858–5,661 years, which places it at neolithic period in southern denmark.

Sequence of human genome to an average depth of 2.3× was found. Interesting thing is that the individual who chewed the pitch was female and that she was genetically more closely related to  mainland Europe than from central Scandinavia. 

They also found that she likely had dark skin, dark brown hair and blue eyes. 

These birch pitches are widely used as adhesives and gums which has the potential to resist bacteria and viruses and protect the DNA data.

The research highlights the potential of chewed birch pitch as a transmitter of DNA of ancient people.