[music playing]
NARRATOR: Sima de las
Palomas, Spain, 2011.
Archaeologists unearth a
prehistoric grave containing
three individuals buried side
by side with their arms folded
in a ritualistic fashion.
Because of the manner
of their burial,
the archaeologists assume the
remains are human, but are
surprised to discover
that they are
actually our evolutionary
cousin, Neanderthal.
It takes a good
deal of imagination
to prepare the dead.
It suggests some kind of
notion of an afterlife.
If there is that, there
is usually a notion
of a deity of some kind.
That is fairly complicated
religious thinking,
suggesting that the
Neanderthals had
a capacity for
symbolic reasoning
and the formation of culture.
This suggests a level of
civilization, or at least,
the protoculture,
that is further
along than we used to think.
Neanderthals, unfortunately,
because of early discoveries
that made them look
like a brutish caveman,
not intelligent,
that they're very,
very different from us, they
were shorter and stockier--
but they had huge brains.
They clearly had clothing.
They cared for their
sick and elderly.
They were very intelligent.
NARRATOR: In 2014,
scientists analyzed materials
from 40 different
archaeological sites
to determine a
reliable extinction
date for Neanderthals.
The date they came up
with is 40,000 years ago,
suggesting they coexisted
with Homo sapiens
for at least 1,000 years.
But just why did they die off?
At this point, we
don't know exactly why
these other species died off.
Certainly, it does
broadly coincide
with the expansion of
anatomically modern humans
to all parts of the globe.
But contrary to our
notions from the past,
it doesn't look like it was a
lack of intelligence that led
to the demise of Neanderthals.
NARRATOR: Although Neanderthals
are long extinct, in 2013,
evolutionary
geneticists discovered
select modern human
populations carry genomes
from both Neanderthal
and Denisovans,
suggesting that, at some
point, interbreeding occurred.
Neanderthal genetic
markers are concentrated
in populations in Europe and
parts of the Middle East.
Denisovan markers can be
found in the mainland Asian
populations, as well as
Pacific Islander, New Guineans,
and Australian Aborigines.
According to some ancient
astronaut theorists,
this interbreeding may be the
key to understanding the demise
of the other intelligent
hominid species that once
shared the planet with humans.
Consider the possibility that
these different hominid strains
were meant to be
kept geologically
separated from each other
across tracts of land that were
considered to be too vast
for them to ultimately come
into contact with one another.
Is it possible that
interbreeding was frowned upon
and that once interbreeding
with Neanderthals
started to take place, it
was damaging the very essence
of the experiment,
and because of that,
the Neanderthal strain
had to be terminated
or removed from the planet
to stop this from happening?
When we look at ancient texts,
particularly religious texts
from millennia ago, what we
find is the idea of the gods
or a god wanting to
create a human that was
pure, physically and morally.
What we also find are accounts
where the wrath of God
or the wrath of
the gods hammered
down on us for,
essentially, going
off the rails, so to speak.
And we could make a case
that this was some example
of extraterrestrial intervention
to essentially try and purify,
again, the species.
And that might have
involved wiping
out significant portions of
early humans and starting over.
