IRA FLATOW, HOST:
This is SCIENCE FRIDAY, I'm Ira Flatow. This next story is about the caveman and the artist. Well actually, about the caveman who was an artist or perhaps an artiste, decorating his cave walls with a palette of pigments. Researchers say they found a Spanish cave painting that's at least 40,800 years old, old enough for archaeologists to wonder if a Neanderthal painted it.
How did scientists date this cave art without destroying it? Is there any way to prove without a doubt that Neanderthals dabbled in painting just like us? Joining me now to talk more about the research published in the journal Science is Alistair Pike. He is a reader in archaeological sciences at the Bristol in England. He joins us by phone. Welcome to SCIENCE FRIDAY, Dr. Pike.
ALISTAIR PIKE: Good evening.
FLATOW: Could you describe the paintings for us?
PIKE: Yes, well, I mean, we looked at more than 50 paintings in total, but the ones we're particularly interested in are the ones that are coming out with these very early ages, and they are non-figurative. So they're not pictures of animals, bison and so on that we normally associate with cave art. But they are things like hand stencils, where you place your hand against the wall of a cave, and then you spit or you blow pigment onto it, and then when you take your hand away, it's left a negative imprint, as it were, of your hand.
There are hand stencils, there are round disks, and there are kind of enigmatic symbols.
FLATOW: And you have, I guess, re-dated them, then.
PIKE: Well, we've - they've never been dated before, and there's a real problem with trying to date cave art. And one of the biggest problems is that the normal dating method we use in archaeology, radio carbon dating, requires there to be some sort of organic material in the pigment. And there is if you use charcoal to make a drawing, for example, but in these mineral pigment paintings, or in the case for example of engravings, there's no way we can use radio carbon dating to date them.
FLATOW: So what did you do?
PIKE: So we developed a technique, or rather we borrowed a technique, which dates the formation of thin calcium carbonate crusts. These are rather like stalagmites and stalactites that grow in caves, and we find tiny versions of stalagmites growing on top of the art.
And within those stalactites, there are trace amount of uranium, which is radioactive, and it's decaying to thorium. And we measure the ratio of thorium to uranium, and that tells us how long since the stalagmite formed. Now, since this is on top of the painting, we know the painting must have been there before the stalactite could form on it. So we get a minimum age for the painting.
FLATOW: Which is 40,000?
PIKE: The oldest one is 40,800, but it could be much older than that. We don't know how long has passed between the painting being done and the stalactite growing on its surface.
FLATOW: Is there a limit number?
PIKE: We can - this dating method can go back to half-a-million years.
FLATOW: I guess I mis-asked the question. Is there a top number for the painting that it could be?
PIKE: No, unfortunately not, no, no, absolutely not. We've only got a minimum age for this painting.
PIKE: So it could be very significantly older than 40,800.
FLATOW: So it could have been done by a Neanderthal?
PIKE: It could have, and in fact, it doesn't have to be much older than the stalagmite to have to have been done by Neanderthals. So in early Spain, the earliest evidence for the arrival of modern humans is only about 41 and a half thousand years ago. So we've got a date of 40,800. So if it took more than 700 years between the painting being done and the stalagmite forming, then it must have been Neanderthal.
FLATOW: Do we know of any other sort of artistic behavior among Neanderthals?
PIKE: Well, we do, we do, and these are fairly recent discoveries, and I think in the past, Neanderthals have got rather bad press, and they're thought as kind of like knuckle-dragging cavemen. But actually if you look carefully in the archeological record, you find that Neanderthals are actually deploying artifacts to represent something symbolic.
So we find, for example, perforated shell beads that look like they were strung into necklaces and part of kind of body adornment. We find shells that have clearly been used as receptacles for ground-up colored minerals, which were probably either for painting or perhaps for body decoration. And we have bones that have geometric engravings on them.
FLATOW: So how many sites are available for you to now use this new technique where you could not use it before?
PIKE: Oh hundreds. I mean, we've looked at, well, probably less than one percent of the art in Spain, and there's at least the same number of artistic panels in Southern France, and then there's Italy and so on and so forth. So I expect our understanding of the age of this stuff is going to improve as we get to sample more and more sites.
FLATOW: 1-800-989-8255. Let's go to the phones, to John(ph) in Moab, Utah. Hi, John.
JOHN: Good afternoon.
FLATOW: Hi there.
JOHN: I have an interesting observation. I recently watched "The Cave of Forgotten Dreams," filmed by Werner Herzog, and I forget the name of the cave, but it's in France.
PIKE: Chauvet Cave.
JOHN: And I went to art school, and what I saw on the walls of the cave so astounded me, I actually got the DVD, and I've watched it several times to really look at the images and to even stop and consider. These images, you see very much, very often in art school, where someone repeats the image. You know, here's the head of the horse, and now we're going to make it a little bit longer in the next drawing and a little bit fatter in the next drawing, as if the artist is studying the effect of making this shape slightly different.
And I wonder if anyone has considered that this could be the sketchpad of the artist and perhaps even represents something maybe like an art school.
PIKE: That's a very careful observation and one that very recently a team, what they did was they took each of those images, and quite often they're superimposed upon each other. They noticed them, one after the other, and they actually saw what looked a bit like a movie.
And it's almost as though - you know how in kind of comic books to convey perhaps someone throwing a baseball they might have, you know, three arms and the ball, it looks as though there may have been an attempt to actually convey a sense of motion in these things, or of movement.
JOHN: I saw that, too, but what I've seen in art school is maybe you draw the legs of the horse one way, and you don't really like it. You don't redraw the whole thing. You just draw another set of legs in. You even see this in the great masters, when they begin to do X-ray studies of their paintings and such. Well, wait a minute, look, they did it differently, and they painted over it.
PIKE: Absolutely, absolutely, and...
JOHN: And I very much thought these are studies. There were very few completed paintings, as opposed to, say, in Lascaux where you see this wonderful gallery of completed images, you know, colored in and very much in relation to one another. And in this case, you saw often a hodgepodge, where someone has done this and then put something right next to it and then right on top of it and so on. And I wondered if anyone has given these images to an art school and said, what does it look like to you.
FLATOW: Thank you, John.
PIKE: This may indeed be a Paleolithic art school, and in fact the interesting thing about that particular cave is that it has some very early examples of figurative art, in fact probably the earlier figurative art we have in Europe. And it seems to come before the great kind of flourishing figurative art. So if indeed it is an art school, it was very successful because people then went on to paint lots of other caves.
And what's interesting is that the art we see is always done so well. We very rarely see bad art that, you know, looks like it's a practice except maybe in the cases you were describing. Where are these people actually learning to draw these forms so well?
FLATOW: You've got me - natural talent. I can't play hangman because I can't draw the sticks.
FLATOW: For the figure. This is fascinating. Where do you go from here? Do you have other caves set to go into?
PIKE: Even on the handprints and the disks from El Castillo Cave, which has this early date of 40,800, there are probably another 15 or 20 samples that we can date. We only took two because we were trying to find out where we should be looking. Now we know where we should be looking. We know the type of art we're looking for.
We can go back to Spain. We can go, then, into France, and we're hoping to go to Italy, as well.
FLATOW: And you mentioned the Chauvet cave paintings. They don't compare at all to these?
PIKE: They are exceptionally different. Yes, they are figurative. They're drawings of animals. They're made with charcoal, for a start. If you put them next to the art we've dated, you would not be able to compare them at all. You would say there's a huge difference here.
Now that difference, of course, might be one was painted by modern humans, and one was painted by Neanderthal.
FLATOW: No way to know that yet.
PIKE: Not yet, but all we have to do is go back and find a piece of calcite that's a few hundred or maybe a thousand years older, and we'll nail it.
FLATOW: You're betting on it, it sounds like.
PIKE: We're pretty confident, yes. I know we have a few detractors out there, but I find it very hard to just concede that we happen to have found this piece of calcite that grew almost instantaneously once the painting had been finished.
FLATOW: Do you have any others that you're working on, and you can't tell us about yet?
PIKE: We've been to another UNESCO World Heritage site, which is just completely covered in handprints. Now, we haven't gotten any results from there, but our feeling is that it's all very old in this case, and as soon as we get some results, we shall reveal it to everyone.
FLATOW: What makes any cave a good spot for finding the handprints in?
PIKE: Well, that's actually a really interesting question, and it's not just a good spot for us to find them. It means it was a good spot for someone to paint them. And in all of these caves, what we're finding - or many of these caves, let's say, is that actually there were several periods of painting.
So in Altamira, the famous Altamira Cave, we've got some of these red symbols that were painted 36,000 years ago, and then we've got the wonderful polychrome, the multi-colored bison that were painted 18,000 years ago. So people were revisiting the cave over a period of 20,000 years and deciding that this was the place they were going to leave some paintings.
So I think there's something special about the locations people are choosing, and they're doing that over long periods of time. We're usually told about paintings that have been discovered. There's only one instance when we've actually discovered something that no one else has ever seen before.
FLATOW: So in likelihood, there was a river that ran by or something that was - made this an ideal place for either them to live or to paint in?
PIKE: Excuse me - yes, certainly. I mean, there are - these things certainly are in locations in the landscape which seem to have good views, although that might be partly because in this part of Spain, the limestone rises up quite steeply, so the caves are actually, you know, up the side of hills and so on.
But invariably there are rivers in the valley, and if you were sitting there waiting to hunt something, it would be a fantastic place to spot your prey.
FLATOW: Well, Alistair Pike, this has been fascinating. Please come back and tell us more about your paintings when you find them.
PIKE: We will do absolutely.
FLATOW: You're very welcome. Alistair Pike is a reader in archaeological sciences at the University of Bristol in England. We're going to take a break. When we come back, we're going to look at two deadly viruses, HIV and Ebola, and the scientific detective work behind their discovery with the guy who should be in a movie about how - the risks he took in researching these viruses. He'll talk about them when he gets here. So stay with us. We'll be right back after this break.
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FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR. Transcript provided by NPR, Copyright NPR.