0:00:01.067,0:00:03.319
There's something about caves.

0:00:04.805,0:00:08.822
A shadowy opening in a limestone[br]cliff that draws you in.

0:00:10.006,0:00:13.568
As you pass through the portal[br]between light and dark,

0:00:13.568,0:00:15.982
you enter a subterranean world.

0:00:16.229,0:00:21.701
A place of perpetual gloom,[br]of earthy smells, of hushed silence.

0:00:22.793,0:00:24.491
Long ago in Europe,

0:00:24.491,0:00:27.388
ancient people also entered[br]these underground worlds.

0:00:27.901,0:00:29.374
As witness to their passage,

0:00:29.374,0:00:32.415
they left behind mysterious[br]engravings and paintings.

0:00:32.986,0:00:39.324
Like this panel of humans, triangles[br]and zig-zags from Ojo Guareña in Spain.

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You now walk the same path[br]as these early artists.

0:00:44.038,0:00:46.926
And in this surreal, other-worldly place,

0:00:46.926,0:00:49.220
it's almost possible to imagine

0:00:49.220,0:00:53.573
that you hear the muffled foot-fall[br]of skin boots on soft earth,

0:00:53.573,0:00:56.762
or that you see the flickering of a torch[br]around the next bend.

0:00:57.946,0:00:59.456
When I'm in a cave,

0:00:59.456,0:01:05.299
I often find myself wondering,[br]what drove these people to go so deep?

0:01:05.299,0:01:08.882
To brave dangerous and narrow[br]passageways to leave their mark?

0:01:09.420,0:01:10.441
In this video clip,

0:01:10.674,0:01:13.692
that was shot half a kilometer,[br]or about a third of a mile underground,

0:01:13.924,0:01:15.898
in the cave of Curon in Spain,

0:01:16.200,0:01:18.150
we found a series[br]of red paintings on a ceiling

0:01:18.429,0:01:20.913
in a previously unexplored[br]section of the cave.

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As we crawled forward, military-style,[br]with the ceiling getting ever-lower,

0:01:25.766,0:01:28.552
we finally got to a point[br]where the ceiling was so low,

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that my husband and project[br]photographer, Dylan,

0:01:31.524,0:01:35.193
could no longer achieve focus[br]on the ceiling with his DSLR camera.

0:01:35.727,0:01:37.004
So while he filmed me,

0:01:37.329,0:01:40.533
I kept following the trail of red paint[br]with a single light,

0:01:40.835,0:01:44.434
and a point-and-shoot camera[br]that we kept for that type of occasion.

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Half a kilometer underground.

0:01:48.288,0:01:49.681
Seriously.

0:01:50.192,0:01:53.095
What was somebody doing down there[br]with a torturous stone lamp?

0:01:53.373,0:01:54.395
(Laugher)

0:01:54.627,0:01:56.392
I mean --me, it makes sense, right?

0:01:56.694,0:01:57.924
But you know,

0:01:58.133,0:02:00.896
this is the kind of question that[br]I'm trying to answer with my research.

0:02:01.361,0:02:03.775
I study some of[br]the oldest art in the world.

0:02:04.751,0:02:06.933
It was created by these[br]early artists in Europe,

0:02:07.305,0:02:09.603
between 10 thousand[br]and 40 thousand years ago.

0:02:11.864,0:02:12.932
And the thing is,

0:02:12.932,0:02:15.094
is that I'm not just studying it[br]because it's beautiful,

0:02:15.327,0:02:17.230
though some of it certainly is.

0:02:17.834,0:02:21.410
But what I'm interested in[br]is the development of the modern mind,

0:02:21.735,0:02:26.332
of the evolution of creativity,[br]of imagination, of abstract thought.

0:02:26.890,0:02:29.838
About what it means to be human.

0:02:31.417,0:02:34.389
While all species communicate[br]in one way or another,

0:02:34.738,0:02:37.802
only we humans have really taken it[br]to another level.

0:02:38.197,0:02:40.589
Our desire and ability[br]to share and collaborate,

0:02:40.960,0:02:43.305
has been a huge part of out success story.

0:02:43.584,0:02:47.856
Our modern world is based on a global[br]network of information exchange.

0:02:48.251,0:02:51.896
Made possible, in large part,[br]by our ability to communicate.

0:02:52.361,0:02:56.076
In particular, using graphic[br]or written forms of communication.

0:02:56.772,0:02:58.142
The thing is though,

0:02:58.421,0:03:00.441
that we've been building[br]on the mental achievements

0:03:00.766,0:03:03.042
of those that came before us for so long,

0:03:03.645,0:03:07.848
that it's easy to forget that certain[br]abilities haven't already existed.

0:03:08.870,0:03:10.866
It's one of the things[br]I find most fascinating

0:03:11.308,0:03:13.931
about studying our deep history.

0:03:14.210,0:03:18.064
Those people didn't have the shoulders[br]of any giants to stand on,

0:03:18.320,0:03:20.177
they were the original shoulders.

0:03:20.781,0:03:23.289
And while a surprising number[br]of important inventions

0:03:23.590,0:03:25.309
come out of that distant time,

0:03:25.727,0:03:30.254
what I want to talk to you about today[br]is the invention of graphic communication.

0:03:31.020,0:03:33.180
There are three[br]main types of communication,

0:03:33.458,0:03:36.314
spoken, gestural -- [br]so things like sign language,

0:03:36.639,0:03:38.892
and graphic communication.

0:03:39.217,0:03:42.235
Spoken and gestural are,[br]by their very nature, ephemeral.

0:03:42.607,0:03:45.997
It requires close contact for a message[br]to be sent and received.

0:03:46.484,0:03:50.292
And after the moment of transmission,[br]it's gone forever.

0:03:50.571,0:03:53.729
Graphic communication, on the other hand,[br]decouples that relationship,

0:03:54.402,0:03:57.838
and with its invention, it became possible[br]for the first time,

0:03:58.396,0:04:01.043
for a message to be[br]transmitted and preserved,

0:04:01.461,0:04:04.200
beyond a single moment in place and time.

0:04:05.059,0:04:06.685
Europe is one of the first places

0:04:06.917,0:04:09.564
that we start to see graphic marks[br]regularly appearing

0:04:09.866,0:04:13.697
in caves, rock shelters, and even[br]a few surviving open air sites.

0:04:14.533,0:04:16.948
But this is not the Europe we know today.

0:04:17.296,0:04:19.920
This was a world dominated[br]by towering ice sheets

0:04:20.175,0:04:22.195
by towering ice sheets, three to four[br]kilometers high,

0:04:22.497,0:04:25.214
with sweeping grass plains[br]and frozen tundra.

0:04:25.492,0:04:27.535
This was the Ice Age.

0:04:28.325,0:04:29.509
Over the last century,

0:04:29.765,0:04:33.990
more than 350 Ice Age rock art sites[br]have been found across the continent.

0:04:34.942,0:04:39.261
Decorated with animals, abstract shapes,[br]and even the occasional human.

0:04:39.516,0:04:42.605
Like these engraved figures[br]from Grotta dell'Addaura in Sicily.

0:04:43.092,0:04:46.064
They provide us with a rare glimpse

0:04:46.320,0:04:50.081
into the creative world and imagination[br]of these early artists.

0:04:50.332,0:04:51.539
Since their discovery,

0:04:51.818,0:04:54.999
it's been the animals that have received[br]the majority of the study.

0:04:55.556,0:04:58.458
Like this black horse[br]from ( TBD ), Spain.

0:04:58.876,0:05:02.824
Or this unusual purple bison[br]from La Pasiega.

0:05:03.265,0:05:07.560
But for me, it was the abstract shapes --[br]what we call geometric signs,

0:05:08.512,0:05:10.137
that drew me to study the art.

0:05:11.693,0:05:13.736
The funny this is, that at most sights,

0:05:14.015,0:05:17.777
the geometric signs far outnumber[br]the animal and human images.

0:05:18.334,0:05:21.050
But when I started on this back in 2007,

0:05:21.561,0:05:25.021
there wasn't even a definitive list[br]of how many shapes there were,

0:05:25.439,0:05:26.902
nor was there a strong sense

0:05:27.203,0:05:29.665
of whether the same ones appeared[br]across space or time.

0:05:32.428,0:05:34.796
Before I could even[br]get started on my questions,

0:05:35.191,0:05:37.536
my first step was to compile a database

0:05:37.838,0:05:41.088
of all known geographic signs[br]from all of the rock art sites.

0:05:41.576,0:05:45.175
The problem was that while they were[br]well documented at some sites,

0:05:45.430,0:05:47.056
usually the ones[br]with the very nice animals,

0:05:47.636,0:05:51.096
there was also a large number of them[br]where it was very vague --

0:05:51.374,0:05:53.023
there wasn't a lot[br]of description or detail.

0:05:53.433,0:05:56.057
Some of them hadn't been visited[br]in half a century, or more.

0:05:56.777,0:05:59.749
These were the ones[br]that I targeted for my field work.

0:06:00.236,0:06:02.024
Over the course of two years,[br]

0:06:02.628,0:06:06.854
my faithful husband Dylan and I[br]each spent over 300 hours underground,

0:06:07.318,0:06:10.917
hiking, crawling and wriggling[br]around 52 sites

0:06:11.312,0:06:14.191
in France, Spain, Portugal and Sicily.

0:06:14.493,0:06:15.770
And it was totally worth it.

0:06:16.304,0:06:21.923
We found new, undocumented geometric signs[br]at 75 percent of the sites we visited.

0:06:22.782,0:06:25.638
This is the level of accuracy[br]I knew I was going to need

0:06:25.917,0:06:28.517
if I wanted to start answering[br]those larger questions.

0:06:28.982,0:06:31.280
So let's get to those answers.

0:06:31.721,0:06:36.087
Barring a handful of outliers,[br]there are only 32 geometric signs.

0:06:36.388,0:06:40.777
Only 32 signs

0:06:41.125,0:06:43.308
across a 30,000 year time span,[br]and the entire continent of Europe.

0:06:43.950,0:06:46.457
That is a very small number.

0:06:46.759,0:06:49.058
Now if these were random[br]doodles or decorations,

0:06:49.290,0:06:51.380
we would expect to see[br]a lot more variation,

0:06:51.682,0:06:53.887
but instead what we find[br]are the same signs,

0:06:54.143,0:06:56.627
repeating across both space and time.

0:06:57.138,0:07:00.969
Some signs start out strong,[br]before losing popularity and vanishing,

0:07:01.248,0:07:03.616
while other signs are later inventions.

0:07:03.964,0:07:08.446
But 65 percent of those signs stayed[br]in use during that entire time period.

0:07:08.980,0:07:12.718
Thigns like lines, rectangles[br]triangles, ovals and circles.

0:07:13.433,0:07:15.569
Like we see here,[br]from the end of the Ice Age,

0:07:15.778,0:07:19.028
at a 10 thousand-year-old site,[br]high in Pyrenees Mountains.

0:07:19.586,0:07:22.395
And while certain signs span[br]thousands of kilometers,

0:07:22.813,0:07:25.367
other signs had much more[br]restricted distribution patterns,

0:07:25.474,0:07:28.051
with some being limited[br]to a single territory,

0:07:28.376,0:07:30.280
like we see here with these[br]divided rectangles

0:07:30.559,0:07:32.626
that are only found in northern Spain,

0:07:32.927,0:07:35.319
and what some researchers have speculated

0:07:35.667,0:07:37.989
could be some sort[br]of family or clan signs.

0:07:38.291,0:07:39.614
On a side note,

0:07:39.893,0:07:42.981
there is surprising degree similarity[br]in the earliest rock art

0:07:43.260,0:07:46.975
found all the way from France and Spain[br]to Indonesia and Australia.

0:07:47.718,0:07:51.154
With many of the same signs[br]appearing in such far-flung places,

0:07:51.828,0:07:54.451
especially in the 30 thousand[br]to 40 thousand-year range,

0:07:54.791,0:07:57.577
it's starting to seem increasingly likely

0:07:57.925,0:08:02.081
that this invention actually traces back[br]to a common point of origin in Africa,

0:08:02.639,0:08:04.984
but that I'm afraid,[br]is a subject for a future talk.

9:59:59.000,9:59:59.000
So back to the matter at hand.

9:59:59.000,9:59:59.000
There could be no doubt that these signs[br]were meaningful to their creators,

9:59:59.000,9:59:59.000
like these 25 thousand-year-old[br]___________ sculptures

9:59:59.000,9:59:59.000
from La Roque de Venasque in France.

9:59:59.000,9:59:59.000
We might not know what they meant[br]but the people of the time certainly did.

9:59:59.000,9:59:59.000
The repetition of the same signs,[br]for so long, and at so many sites,

9:59:59.000,9:59:59.000
tells us that the artists[br]were making intentional choices,

9:59:59.000,9:59:59.000
If we're talking about geometric shapes,

9:59:59.000,9:59:59.000
with specific, culturally recognized,[br]agreed upon meanings,

9:59:59.000,9:59:59.000
than we could very well be looking

9:59:59.000,9:59:59.000
at one of the oldest systems of graphic[br]communication in the world.

9:59:59.000,9:59:59.000
I'm not talking about writing yet.

9:59:59.000,9:59:59.000
There's just not enough[br]characters at this point,

9:59:59.000,9:59:59.000
to have represented all of the words[br]in the spoken language,

9:59:59.000,9:59:59.000
something which is a requirement[br]for a full writing system.

9:59:59.000,9:59:59.000
Nor do we see the signs[br]repeating regularly enough

9:59:59.000,9:59:59.000
to suggest that they were[br]some sort of alphabet.

9:59:59.000,9:59:59.000
But what we do have[br]are some intriguing one-offs

9:59:59.000,9:59:59.000
like this panel from La Pasiega in Spain[br]known as "The Inscription",

9:59:59.000,9:59:59.000
with its symmetrical markings on the left,

9:59:59.000,9:59:59.000
possible stylized representations[br]of hands in the middle,

9:59:59.000,9:59:59.000
and what looks a bit like[br]a bracket on the right.

9:59:59.000,9:59:59.000
The oldest systems of graphic[br]communication in the world --

9:59:59.000,9:59:59.000
Sumerian cuneiform, Egyptian hieroglyphs,[br]the earliest Chinese script,

9:59:59.000,9:59:59.000
all emerged between four thousand[br]and five thousand years ago,

9:59:59.000,9:59:59.000
with each coming into existence[br]from an earlier protosystem

9:59:59.000,9:59:59.000
made of counting marks[br]and pictographic representations,

9:59:59.000,9:59:59.000
where the meaning[br]and the image were the same.

9:59:59.000,9:59:59.000
So a picture of a bird would really have[br]represented that animal.

9:59:59.000,9:59:59.000
It's only later that we start to see[br]these pictographs become more stylized,

9:59:59.000,9:59:59.000
until they almost become unrecognizable.

9:59:59.000,9:59:59.000
And that we also start to see

9:59:59.000,9:59:59.000
more symbols being invented to represent[br]all those missing words in the language --

9:59:59.000,9:59:59.000
things like pronouns, adverbs, adjectives.

9:59:59.000,9:59:59.000
So knowing all this,

9:59:59.000,9:59:59.000
it seems highly unlikely the geometrics[br]signs from Ice Age Europe

9:59:59.000,9:59:59.000
were truly abstract written characters.

9:59:59.000,9:59:59.000
Instead what's much more likely

9:59:59.000,9:59:59.000
is that these early artists[br]were also making counting marks,

9:59:59.000,9:59:59.000
maybe like this row lines[br]from Reparo de Za Minica in Sicily,

9:59:59.000,9:59:59.000
as well as creating stylized[br]representations

9:59:59.000,9:59:59.000
of things from the world around them.

9:59:59.000,9:59:59.000
Could some of the signs[br]be weaponry or housing?

9:59:59.000,9:59:59.000
Or what about celestial objects[br]like star constellations?

9:59:59.000,9:59:59.000
Or maybe even rivers, mountains,[br]trees-- landscape features.

9:59:59.000,9:59:59.000
Possibly like this black peniform[br]surrounded by strange bell-shaped signs

9:59:59.000,9:59:59.000
from the site of El Castillo, in Spain.

9:59:59.000,9:59:59.000
The term peniform means[br]"feather-shaped" in Latin,

9:59:59.000,9:59:59.000
but could this actually be[br]a depiction of a plant or a tree?

9:59:59.000,9:59:59.000
Some researchers have begun

9:59:59.000,9:59:59.000
to ask these questions[br]about certain signs at specific sites,

9:59:59.000,9:59:59.000
but I believe the time has come[br]to revisit this category as a whole.

9:59:59.000,9:59:59.000
The irony in all of this, of course,

9:59:59.000,9:59:59.000
is that having just carefully classified[br]all the signs into a single category,

9:59:59.000,9:59:59.000
I have a feeling that my next step[br]will involve breaking it back apart

9:59:59.000,9:59:59.000
as different types of imagery[br]are identified and separated off.

9:59:59.000,9:59:59.000
Now don't get me wrong,

9:59:59.000,9:59:59.000
the later creation[br]of fully-developed writing

9:59:59.000,9:59:59.000
was an impressive feat in its own right,

9:59:59.000,9:59:59.000
but it's important to remember

9:59:59.000,9:59:59.000
that those early writing systems[br]didn't come out of a vacuum.

9:59:59.000,9:59:59.000
And that even five thousand years ago,

9:59:59.000,9:59:59.000
people were already building[br]on something much older,

9:59:59.000,9:59:59.000
with its origins stretching back[br]tens of thousands of years --

9:59:59.000,9:59:59.000
to the geometric signs[br]of Ice Age Europe and far beyond,

9:59:59.000,9:59:59.000
to that point, deep in our[br]collective history,

9:59:59.000,9:59:59.000
when someone first came up with the idea[br]of making a graphic mark,

9:59:59.000,9:59:59.000
and forever changed the nature[br]of how we communicate.

9:59:59.000,9:59:59.000
Thank you.

9:59:59.000,9:59:59.000
(Applause)