DNA extracted from 5,000-year-old birch pitch chewing gum found in mud

Forget the gold crowns and marble statues. The real dirt on history is literally in the trash. Archaeologists found a 5,700-year-old wad of gum—actually birch pitch—tossed into the mud like a used cigarette butt.

This sticky, antiseptic tree resin trapped a woman’s saliva so perfectly that we now have her entire genome. We know she had dark skin, blue eyes, and had just snacked on duck and hazelnuts before spitting her gum out.

It’s the ultimate biological time capsule, proving that our discarded leftovers are way more honest than any monument.

Wait, why on earth were they chewing on tree resin anyway?

It definitely wasn't for the minty-fresh breath. Birch pitch was the prehistoric version of industrial superglue. They used this sticky gunk to fix flint blades onto wooden handles, but there was a catch: it hardens into a rock the second it gets cold.

Chewing it was the only way to keep the "glue" soft and pliable while they worked. It’s basically a tool-repair kit you carry in your mouth. Plus, those antiseptic properties made it a handy prehistoric aspirin for treating gum infections or toothaches.

How do you actually turn a tree into industrial glue?

You don’t just tap it like maple syrup. This wasn't a "nature provides" moment; it was a "prehistoric chemistry lab" moment. To get the pitch, they had to cook birch bark in a hole with almost no oxygen.

If you just burn it, you get ash. But if you bake it just right, the bark "sweats" this thick, black tar. It’s actually the first synthetic material humans ever manufactured.

Imagine our ancestors running a tiny, smoky oil refinery in the dirt. It’s messy, it smells like a campfire's worst nightmare, but it’s the only way to get that sticky gold.

So they just buried it? How does that even work without a vacuum?

Exactly. You don't need a high-tech vacuum chamber when you have a pile of dirt. They’d pack the birch bark into a pit and seal it tight with a thick "lid" of clay or moist soil.

Then, they’d build a massive bonfire right on top of that seal. The heat radiates downward, baking the bark in its own juices. Since the dirt blocks the air, the bark can't ignite. It just melts.

The black goo drips down into a collection jar at the bottom. It’s the ultimate prehistoric hack: using a dirt sandwich to turn trash bark into high-performance glue.

Did they really have 'collection jars' lying around thousands of years ago?

'Jar' is a generous term for what was basically a prehistoric puddle-catcher. Before fancy pottery, they’d just dig a smaller hole beneath the bark-pit and line it with a big leaf or a thick layer of cold clay.

The tar would drip down and pool in that little divot. Once the fire died out, they’d dig it up like a disgusting, sticky treasure chest.

It’s not a Mason jar; it’s a mud-caked pocket of goo. Sometimes they used a hollowed-out stone, but usually, the earth itself was the only Tupperware they needed.