This is a portrait of a woman who lived 5,700 years ago, all based on information trapped within chewing gum! (Tom Björklund)
Do you chew gum? Would you believe us if we said that it might be the key to immortality? Better not spit it out!
Hold on, what?
Anyway, a group of scientists from the University of Copenhagen in Denmark have pulled off an incredible feat. They used a 5,700-year-old piece of chewing gum to reconstruct the entire genome of an ancient woman. The picture at the top of this post is what they believe she looked like!
So many questions. What's in a genome? How did they do that? And did humans really have Juicy Fruit 5,000 years ago?! Let's dig into it...
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The discarded piece of birch tar, a.k.a. ancient chewing gum. (Theis Jensen)
To be clear, this case doesn't feature the fruity or minty chewing gum that we're all used to. But for thousands of years, humans have indeed chewed the gums, tars, or saps of trees. Sometimes, this stuff was chewed as medicine. Or humans chewed it to soften it up so it could be used as a glue. Or they chewed it simply because chewing is fun!
Whatever the reason for the chewing, when scientists have discovered discarded pieces of this gum, they have sometimes found traces of human saliva within it. Even after centuries or millennia! Most likely because the act of chewing has pressed and sealed the saliva inside the gum itself.
Which then leads to...
The guide to you and me
The genome. What is it?
A visualization, or picture, of a human genome sequence. There are literally millions of different variables that change how we turn out as human beings. (© Tartilastock - Dreamstime.com)
We all have a unique genome, and it's full of a bunch of cool stuff. As in the 23 chromosome pairs encoded as DNA molecules that are a unique guide to who each of us are. Think of it as your own particular recipe or blueprint. Evidence of our genome is left behind in every piece of us. Our hair, skin, flesh, blood, organs... and our saliva.
In the case of this woman who lived 5,700 years ago, the saliva left behind on the piece of birch tar was enough to reconstruct her entire genome. Of course, this information wasn't enough to actually bring her back to life. Scientists can't do that... yet.
But it was enough to know how she likely would've looked, from the shape of her face to her eye and hair colour to her height. Remarkable stuff! And it gives the idea of recycling chewing gum a whole other meaning!
Cool. Weird, but cool.