Current Event: The Archaeology of Poop

Current Event 

     This is not quite what comes to mind when one thinks of archaeological discoveries.  The examination of ancient poop t is one way that DNA from thousands of years ago can be recovered. The proper archaeological term for the study of poop is called the study of paleofeces or non-hardened fossils.  Paleofeces are studied to determine how the people of the time ate, what their diet consisted of, their health, and even more about the plant and animal life that existed around them.  Yes, all this can be found in the DNA of poop.

      The process of recovering DNA from paleofeces involves a simple five step procedure involving liquid nitrogen, a diabetic drug, a polymerase chain reaction machine, and poop. The nitrogen freezes the poop so it can be ground into a fine powder, the diabetic drug is used to break down the sugar compounds in the surrounding DNA, and the chain reaction machine is used to make millions of copies of the recovered DNA to be compared to other DNA fragments from different sources found at the site.

The reason this is possible is because of the process known as the Maillard reaction, named after Louis Camille Maillard . What happens is that as the feces dries a hard crust forms on the outside . The sugars from the digested plant material begin to react with surrounding amino acids forming  larger sugar compounds.  These basically encase the DNA preserving it for future extraction.

      It is pretty neat to think that so much information can be found in paleofeces that is thousands of years old.  It was Hendrik Poinar and Svante Paabo from the Max Planck Institute in Munich who recovered the first successful DNA sample from paleofeces in 1998.  It was in 2008 that the first human DNA extraction was made by the Kristin Sobolik, archeologist from the University of Maine Orono.

Just recently archaeologists have unearthed 700 year old barrels filled with poop in Denmark.  Unfortunately, the Maillard reaction had not occurred since the waste was sealed in the barrels.  There was no sugar coating to keep the smell in.  Yet the discovery was remarkable and the waste found told a lot about the people who lived in Demark 700 years ago.  The archaeologists just had to endure the smell.  

     I wonder if our society today, with all the waste treatment plants, has inadvertently put an end to DNA sampling of our poop by future scientists?  Who knows, maybe each city will create a time capsule with a little sample of poop to let future generations know about how we existed.