As any historian will tell you, things get more difficult to find, the farther back in time you go.
The news from a few decade ago – that’s easy. Familial history going back centuries. Tricky, but achievable. A way of life conducted thousands or even millions of years ago – a much more difficult proposition. But, depending on what you are looking for, maybe not impossible.
Information is stored in a variety of ways. We need to understand the format before we can decipher the story. But go too far back and depending on what you are looking for, information may no longer be there at all.
Storage Solutions
It’s all in the storage. Drawing on cave walls still exist, where similar ones on bark may have perished. Newspapers kept in boxes will survive. The news written on those used to line the cat’s litter tray will be lost.
The stronger and more constant the surroundings used to store ancient material, the more likely it is to survive.
The same is true of one of our most important pieces of information. The DNA of those that have gone before us.
Hi, Alina here. Me and my friends and cousins make the instructions for your body. We also make them for every other living thing out there. We call ourselves the Dinky Amigos, but you might know us as DNA.
Today I am inside the ear of a person who died thousands of years ago. I am still here because this person was buried in a cave. It’s lovely and cool down here – we don’t like it too hot. There’s not many of us left, so if scientists want to use us to find out about ancient humans, they better hurry up!
Hiding
We are a bit hard to find. We can’t just float about any old where. That leads to degradation – a process where we are torn apart from our friends and destroyed. This can happen in a number of ways. Heat is the worst. It makes us bounce up and down really quickly and separates us all. On our own we have no chance and are degraded very fast.
Light isn’t much better. The sun, especially, has UV rays which damage us. Too much damage and there will be nothing left. Think what happens to your skin when you lay in the sunshine for too long without suncream. Now imagine doing that for thousands of years without a break. Not for me, thank you!
We tend to hang around in bones or teeth so we can surround ourselves with a hard outer shell. There is a titchy, tiny bone in the ear known as the petrous bone. When you are alive, it helps you hear. When you are no longer alive, it helps protect us.
Finding Fragments
This bone and teeth are one of the first places scientist look when they are searching for ancient DNA. They are delighted when they find some, but it is not all plain sailing.
We all live in units called cells and are surrounded by something known as a membrane. It’s a bit like a fence – to keep us in and other stuff out. The easiest way to get rid of this membrane and liberate us from our cells is to use soap. BUT we are old and delicate and soap is too dangerous.
So instead, scientists grind us up! I know, you are probably thinking that is worse – but not to us. You see, we are far too small to be chopped up by your grinders – but our cells aren’t.
As well as being old and delicate. there aren’t very many of us. So any scientists wanting to use us for further study need to find us some friends.
New Friends
This is the best part. We get new, younger friends to dance with!
All Dinky Amigos know that I dance with Tristan, and Gina dances with Crispin. Always. All the ancient Dinky Amigos know that and so do all the new ones.
As we dance, the new ones can copy our instructions and produce an exact replica of the ancient DNA. Scientists can use this for their studies.
What has ancient DNA ever done for us?
Ancient Dinky Amigos have been able to show scientists exactly what kind of instructions we made for your ancient ancestors. Because of us, they now know that about 4% of your own instructions come from Neanderthals and that instructions for blue eyes originated about 10,000 years ago in Europe.
Grouping some of our instructions into things called markers, they can also see where your ancestors came from.
They have also begun to understand just how many different species of human have ever lived and where they made their home.
History is in the instructions of your ancient DNA. You just have to hope it was stored safely enough for you to access the story.