You know what people say
you never have a second chance to make a first
impression
And this is the problem the Neanderthals have
had
for more than 150 years.
Ever since the discovery of Neanderthal fossils
in the nineteenth century, Neanderthals have
had rather bad press
in fact the original name for Neanderthals
was proposed
as ‘Homo Stupidus’ – the stupid human.
And people have variously portrayed them
rather gorilla-like and incapable of belief
systems and symbolic thought.
What we find here is evidence of Neanderthal
painting.
Not only just smearing pigments on the wall
but actually painting something that is symbolic
that represents something.
This panel comprises of various components
so you can see red lines that form squares.
Inside these rectangles that form by these
lines
you can actually see animal paintings.
So here’s the back half of an animal,
we don’t know what type of animal it is.
And here very fading is a front part
here’s a head of an animal, the legs, ears.
On top of these squares you see lots of red
dots.
Nobody really knows what this means
but it’s certainly done by humans who came
in
to these caves and painted the walls.
And the very question is how old,
and when did this happen?
Normally archaeologists would use a technique
called radiocarbon dating which dates
the time that charcoal has been used to make
paintings.
But we can’t do this with these kind of
paintings
because they’re made out of mineral pigments.
So instead we’re focusing on these tiny
white crusts
that have formed on top of the paintings,
and they’re made of calcium carbonate
and they’re formed by the water
percolating through the rocks.
And they precipitate out calcite.
If this calcite was precipitated on top of
the painting
the painting must have been there for it to
precipitate
on top, which means the painting must be older
than the age of the calcite.
Uranium series dating of carbonates is actually
a technique that’s been used in geochronology
for decades now
it’s well established.
Over the last 25 years the developments in
mass spectrometry
means that we can actually date much smaller
samples.
This is really important for archaeology because
it means we can date these small carbonate
crusts found
and associated with cave art.
The samples are first dissolved in a weak
acid to
flush out the uranium and then flush out the
thorium
so that we separate them out into two different
solutions.
The samples are taken to a mass spectrometer
and analysed
in order to determine exactly how much of
the different
isotopes of uranium and thorium are present
in them.
The samples are introduced and then
enter an argon plasma which
ionizes the different atoms of uranium and
thorium
so it gives them a charge
they’re then accelerated
past a magnet which deflects them
according to their master-charge ratio.
And then the signals of each mass are collected.
This tells us exactly how much of each isotope
is present,
and combined with the known decay constants,
allows us to calculate an age for the
mineralisation of the carbonate that we’re
dating.
The exciting thing is that this panel here
has a minimum age of 64 thousand years.
64 thousand years ago in Spain
there was only one
human species living
and that was the Neanderthals.
The modern humans, like us,
they arrived in Spain about 40 thousand years
ago.
So our results mean that this red line,
which is underlying this calcite,
had to be made by Neanderthals.
And the fact that we have this from three
caves
in the north, centre, and south of Spain
older than 65 thousand, shows us that
this was a deliberate part of their symbolical
cultural repertoire.
They are making deliberate decisions
as to where to place these.
And of course it’s in the depths of caves
where they have to be
for one assumes a ritual purpose.
So this is outside of their normal living
zone.
To my mind
this closes the debate
on Neanderthals.
They are part of our family.
They are ancestors.
They were not cognitively distinct or
less endowed in terms of smarts.
They’re just a variant of humankind that
as such, exists no more.
And what we need to do
is look at their archaeology,
look at their skeleton, look at their genes,
in terms of what they tell us about
the human story as a whole.
