0:00:06.440,0:00:09.360
Evolution is possibly the field of science

0:00:09.360,0:00:12.640
that tells the most stories.

0:00:12.640,0:00:14.240
It tells a lot of stories,

0:00:14.240,0:00:18.160
but unlike the myths and tales[br]we tell children

0:00:18.160,0:00:22.320
we try to reconstruct them[br]using evidence, facts and signs.

0:00:22.320,0:00:24.080
A bit like Sherlock Holmes.

0:00:24.080,0:00:29.280
But stories, we know, are slippery:[br]they have pros and cons.

0:00:29.360,0:00:32.000
They can fascinate us,[br]but they can also deceive us.

0:00:32.000,0:00:35.680
They may present us[br]with false reconstructions.

0:00:36.280,0:00:39.720
Many years ago, a colleague of mine,[br]far more illustrious than me --

0:00:39.720,0:00:41.440
his name was J.B.S. Haldane,

0:00:41.440,0:00:44.960
and he was one of the fathers[br]of population genetics --

0:00:44.960,0:00:50.000
was in a very formal salon in Oxford

0:00:50.000,0:00:53.560
in the presence of theologians,[br]ladies and princesses.

0:00:53.560,0:00:56.200
And one of the ladies asked him,

0:00:56.200,0:00:58.440
"Excuse me, Professor Haldane,

0:00:58.440,0:01:01.640
but if you were to imagine the Creator,

0:01:01.640,0:01:04.640
how would you see him?[br]How do you picture him?"

0:01:04.640,0:01:06.360
It was a somewhat loaded question

0:01:06.360,0:01:09.800
because Haldane was known to be[br]an atheist, a disbeliever, a communist.

0:01:09.800,0:01:13.200
He was a bit of an oddball,[br]especially in England in those days.

0:01:13.200,0:01:14.560
And Haldane replied,

0:01:14.560,0:01:16.244
"Look, ma'am, I don't know.

0:01:16.244,0:01:18.240
But if I were to imagine the Creator,

0:01:18.240,0:01:20.148
I think he has

0:01:20.148,0:01:23.200
an inordinate passion for beetles."

0:01:24.240,0:01:25.440
What did Haldane mean?

0:01:25.440,0:01:28.290
He meant that if we look[br]at the earth and biodiversity

0:01:28.290,0:01:30.120
from an evolutionist's point of view,

0:01:30.120,0:01:31.640
the first thing we notice

0:01:31.640,0:01:33.830
is that we are at the edge[br]of the empire,

0:01:33.830,0:01:36.000
we are not at the centre of this story.

0:01:36.000,0:01:40.480
We are one of the many wonderful species[br]created by natural history.

0:01:41.040,0:01:46.040
The story I'm about to tell you[br]is the result of very recent research.

0:01:46.560,0:01:50.200
So let me tell you what we discovered[br]but a few months ago

0:01:50.200,0:01:54.240
and decisively disrupted our way[br]of telling the story of human evolution.

0:01:54.240,0:01:57.160
Basically, it is the story[br]of a disappointment,

0:01:57.160,0:02:00.640
but a constructive disappointment,[br]a disappointment that is good for us,

0:02:00.640,0:02:01.720
that makes us think,

0:02:01.720,0:02:03.320
that once more sets in motion

0:02:03.320,0:02:06.280
the great questions[br]that science is able to raise.

0:02:06.280,0:02:08.840
Where do we come from?[br]Why? What are we doing here?

0:02:08.840,0:02:10.760
What is the place of man in nature?

0:02:10.760,0:02:14.400
The beginning of the story[br]is in this image that you see behind me.

0:02:15.000,0:02:19.700
It is a fascinating, mysterious page[br]written by Charles Darwin himself,

0:02:19.700,0:02:23.000
dating back to July 1837.

0:02:23.000,0:02:26.120
If you remember the dates,[br]it means he was very young.

0:02:26.120,0:02:28.960
He was born in 1809,[br]he was not yet thirty.

0:02:28.960,0:02:30.060
He had just returned

0:02:30.060,0:02:34.800
from a wonderful five-year voyage[br]around the world, which we've all studied.

0:02:34.800,0:02:37.600
He came back in 1836[br]and, as soon as he got back,

0:02:37.600,0:02:40.040
he began writing[br]in these private notebooks.

0:02:40.040,0:02:41.480
Very private.

0:02:41.480,0:02:43.720
So secret that they were[br]to practically become

0:02:43.720,0:02:47.440
the only Darwinian writing[br]that he decided never to publish.

0:02:47.440,0:02:48.760
He is known to have said,

0:02:48.760,0:02:50.760
"I entreat you never to circulate

0:02:50.760,0:02:53.960
what I wrote as a boy[br]just back from my voyage."

0:02:53.960,0:02:55.440
On one of these pages,

0:02:55.440,0:03:00.280
there is this beautiful diagram[br]that he called The Tree of Life.

0:03:00.280,0:03:02.960
And he wrote, see, "I think…",

0:03:02.960,0:03:05.680
because, for the first time,[br]he was writing to himself,

0:03:05.680,0:03:09.050
he was talking to himself about[br]what he'd understood about evolution.

0:03:09.050,0:03:10.786
That is, evolution is a tree

0:03:10.786,0:03:13.600
and like a tree it has a trunk,[br]so common ancestors,

0:03:13.600,0:03:15.280
and then it has ramifications,

0:03:15.280,0:03:18.010
species that diversify over time

0:03:18.010,0:03:21.320
and then become extinct,[br]that multiply and so on.

0:03:21.320,0:03:26.840
An interesting story, a plural story,[br]made up of many different species.

0:03:26.840,0:03:30.120
Why am I telling you a story[br]that is actually a disappointment?

0:03:30.120,0:03:34.880
It is because when we applied[br]this Darwinian idea --

0:03:34.880,0:03:37.640
already back in 1837,[br]then he became famous,

0:03:37.640,0:03:40.580
and 20 years later he published[br]"On the Origin of Species" --

0:03:40.580,0:03:42.840
when we dealed with human evolution,

0:03:42.840,0:03:46.440
scientists themselves[br]actually made an exception.

0:03:46.440,0:03:52.480
And I say scientists themselves,[br]not lay people or opponents of evolution.

0:03:52.480,0:03:56.040
And if you look at how Thomas Henry Huxley[br]reconstructed human evolution,

0:03:56.040,0:03:59.480
you'll see that it's very different[br]from the tree I showed you before.

0:03:59.480,0:04:02.140
The first was a story[br]of diversity, of multiplicity,

0:04:02.140,0:04:04.200
of coexistence of different species.

0:04:04.200,0:04:06.080
This is a very different story,

0:04:06.080,0:04:10.960
where there's only one species at a time,[br]we proceed in a linear fashion.

0:04:10.960,0:04:13.640
This is a great story of progress.

0:04:13.640,0:04:15.656
It's what a colleague of mine,

0:04:15.656,0:04:17.510
who was very important in my training,

0:04:17.510,0:04:18.989
his name was Stephen Jay Gould,

0:04:18.989,0:04:21.560
called "our great illusion".

0:04:21.560,0:04:23.434
The illusion that Homo Sapiens,

0:04:23.434,0:04:26.494
who is always placed at the end,[br]at the far right,

0:04:26.494,0:04:29.200
should represent[br]the culmination of evolution.

0:04:29.200,0:04:34.160
The illusion that the Story[br]should necessarily lead to us.

0:04:34.160,0:04:36.800
Surely this image[br]is very familiar to all of us.

0:04:36.800,0:04:39.960
We always come across it,[br]in newspapers, on television,

0:04:39.960,0:04:41.880
we have seen it many a time.

0:04:41.880,0:04:45.780
What we have recently discovered[br]is that this exception is not valid.

0:04:45.780,0:04:48.380
It's been proved wrong,[br]we've called it into question.

0:04:48.380,0:04:51.520
Human evolution[br]did not take place that way.

0:04:51.520,0:04:55.000
I'll show you other[br]alternatives to this image

0:04:55.000,0:04:57.940
that is used in advertising,[br]it is used everywhere.

0:04:57.940,0:05:00.420
My favourite one is that one[br]at the top right corner.

0:05:00.420,0:05:02.658
It appeared in a feminist magazine

0:05:03.240,0:05:07.160
and it compares the slow and gradual[br]but progressive evolution of the male

0:05:07.160,0:05:09.840
with that of the female,[br]very stable actually.

0:05:09.840,0:05:12.200
I've found all sorts[br]of variants of this image.

0:05:12.200,0:05:14.390
It's a sort of major icon.

0:05:14.390,0:05:15.812
An iconography.

0:05:16.320,0:05:21.480
Even today, when we publish articles[br]on human evolution in newspapers

0:05:21.480,0:05:23.524
they always illustrate it with this image.

0:05:23.524,0:05:25.160
It also happened to me recently.

0:05:25.160,0:05:29.640
The first line of my article was,[br]"There are no missing links in evolution."

0:05:29.640,0:05:33.560
And they accompanied it with this image[br]showing the missing links of evolution.

0:05:33.560,0:05:37.720
So it's something very powerful,[br]deeply rooted in our minds.

0:05:37.720,0:05:42.072
The version that I definitely choose[br]as the absolute best in the world

0:05:42.072,0:05:46.240
is this one that was proposed[br]in The Simpsons

0:05:46.240,0:05:51.120
where evolution culminates inexorably[br]and wonderfully in Homersapiens,

0:05:51.120,0:05:53.200
whom you see at the far right.

0:05:53.200,0:05:55.920
Why is this exception very strange?

0:05:55.920,0:06:02.740
Because while we kept on upholding[br]this great iconography of hope,

0:06:02.740,0:06:04.489
scientists forged ahead

0:06:04.489,0:06:08.540
and rewrote the evolutionary stories,[br]the natural stories of the species

0:06:08.540,0:06:10.000
in a very different way.

0:06:10.000,0:06:13.240
This image is less easy to understand[br]than the previous ones

0:06:13.240,0:06:15.080
but it is wonderful.

0:06:15.080,0:06:16.520
Let me tell you one thing:

0:06:16.520,0:06:20.120
I think that if an alien[br]were to fall to Earth

0:06:20.120,0:06:21.520
and we were to tell him

0:06:21.520,0:06:24.800
about one of the great achievements[br]of science and knowledge --

0:06:24.800,0:06:26.960
yes, true, we have[br]the theory of relativity

0:06:26.960,0:06:29.280
and a lot of discoveries[br]in the field of physics

0:06:29.280,0:06:30.770
but I'd show him this picture,

0:06:30.770,0:06:32.480
and say "Thanks to science,

0:06:32.480,0:06:35.000
the species Homo sapiens[br]has managed to do one thing:

0:06:35.000,0:06:38.200
it's managed to assemble[br]and reconstruct the Tree of Life,

0:06:38.200,0:06:41.680
that is, to decode kinship[br]across all living beings,

0:06:41.680,0:06:45.480
but really all of them, from bacteria[br]up to the most complex animal,

0:06:45.480,0:06:47.970
up to the jaguar, the giraffe,[br]to the humans

0:06:47.970,0:06:50.880
who have inhabited[br]and do inhabit now this planet.

0:06:50.880,0:06:54.120
This Tree of Life brings together[br]all the living beings we know."

0:06:54.120,0:06:55.640
And you see that it is a tree,

0:06:55.640,0:06:58.080
it has many branches,[br]there are many species.

0:06:58.080,0:07:00.760
If you want to find yourself,[br]it is extremely complicated

0:07:00.760,0:07:03.400
because we're here,[br]the animals in here,

0:07:03.400,0:07:06.600
and we happen to be closer related[br]to mushrooms than to plants,

0:07:06.600,0:07:08.640
another thing we don't really like.

0:07:08.640,0:07:10.117
And among animals

0:07:10.117,0:07:13.761
you have to go from twig[br]to twig to twig for nine times

0:07:13.761,0:07:15.160
before you find Homo sapiens.

0:07:15.160,0:07:18.320
In other words, we're at the edge[br]of the biodiversity empire

0:07:18.320,0:07:23.160
as Haldane said with that funny quip[br]when he wanted to shock the lady.

0:07:23.160,0:07:28.240
The same thing holds true[br]if we approach our personal history,

0:07:28.240,0:07:30.960
that of our family: we find[br]the same pattern, can you see?

0:07:30.960,0:07:33.940
I don't want to go into this[br]because it is a bit too technical,

0:07:33.940,0:07:37.960
but if you look at this image[br]we are here, we are this species,

0:07:37.960,0:07:39.920
we are in this genus, the genus Homo.

0:07:39.920,0:07:45.400
If you look back, you find a story[br]of major ramifications like these.

0:07:45.400,0:07:48.240
What you find is a bush, not a ladder.

0:07:48.240,0:07:50.760
You don't find linearity,[br]you find multiplicity.

0:07:50.760,0:07:53.080
And interestingly,[br]if you look at such schemes

0:07:53.080,0:07:56.590
and you draw any time line --

0:07:56.590,0:07:58.840
imagine you have a time machine,

0:07:58.840,0:08:02.920
choose any epoch,[br]10 million years ago, for example,

0:08:02.920,0:08:04.000
and draw the line --

0:08:04.000,0:08:06.880
you will discover that at any time[br]of evolutionary history

0:08:06.880,0:08:10.480
there were many different species[br]existing at the same time,

0:08:10.480,0:08:12.960
more or less related to one another.

0:08:12.960,0:08:15.080
Here you see that if you start from today,

0:08:15.080,0:08:18.240
Homo Sapiens shares[br]a common ancestor with chimpanzees

0:08:18.240,0:08:21.080
who lived some 6/7 million years ago,

0:08:21.080,0:08:23.600
and going further back[br]he shares one with gorillas,

0:08:23.600,0:08:26.880
with orangutans, gibbons[br]and with all the other living beings,

0:08:26.880,0:08:29.800
so this is a very synthetic,[br]very powerful image.

0:08:29.800,0:08:34.880
Why was this powerful image[br]of evolution called into question?

0:08:34.880,0:08:37.650
As is often the case in science,[br]there's a bit of inertia,

0:08:37.650,0:08:40.800
new ideas sometimes have[br]a hard time to be accepted,

0:08:40.800,0:08:42.880
then one is submerged by anomalies.

0:08:42.880,0:08:46.880
That model didn't work and in the end,[br]though reluctantly, we abandoned it.

0:08:46.880,0:08:49.720
This is a beautiful discovery[br]made in 2009,

0:08:49.720,0:08:53.200
and it is so important that Science[br]devoted no less than two covers to it.

0:08:53.200,0:08:59.520
So, the most important discovery of 2009[br]is our possible ancestor called Ardi,

0:08:59.520,0:09:01.080
from Ardipithecus.

0:09:01.080,0:09:02.680
If you look closely at it,

0:09:02.680,0:09:06.480
you can see that it has a mix[br]of modern and archaic features.

0:09:06.480,0:09:10.520
It is a bit ape-like as you can see[br]from its very long upper limbs

0:09:10.520,0:09:11.980
and its divergent big toe,

0:09:11.980,0:09:14.200
yet it is perfectly bipedal,[br]with a flat face

0:09:14.200,0:09:16.400
and therefore presents[br]a mix of characters.

0:09:16.400,0:09:18.820
Now, interestingly, we discovered

0:09:18.820,0:09:20.740
that our ancestor wasn't to be placed

0:09:20.740,0:09:22.800
at the beginning[br]of the evolutionary process

0:09:22.800,0:09:24.830
but lived at the same time as others.

0:09:24.830,0:09:26.610
Look, this is pretty incredible.

0:09:26.610,0:09:30.040
This is a valley in Ethiopia,[br]a single valley in Ethiopia.

0:09:30.040,0:09:35.560
We Sapiens also originated[br]in that area, in one of those valleys.

0:09:35.560,0:09:37.470
In just one of these valleys

0:09:37.470,0:09:40.960
there were no less[br]than three different human genera,

0:09:40.960,0:09:43.320
here shown in different colours,

0:09:43.320,0:09:47.200
and none of them happened to disappear[br]or be replaced by another one.

0:09:47.200,0:09:50.880
They simply lived together in a bushy way.

0:09:50.880,0:09:54.400
Some died out, some new species appeared

0:09:54.400,0:09:58.160
and that complicated[br]and interesting image of evolution,

0:09:58.160,0:10:00.200
which concerns us directly, was created.

0:10:00.200,0:10:04.730
So this is how my colleagues and I[br]rebuilt human evolution.

0:10:04.730,0:10:07.320
See, time flows from bottom to top.

0:10:07.320,0:10:09.160
It's a real bush.

0:10:09.160,0:10:13.040
You see that from the days[br]of our common ancestor with chimpanzees

0:10:13.040,0:10:18.960
there have been about 20, maybe even 22,[br]some even say 25 different species.

0:10:18.960,0:10:20.920
That's anything but a linear evolution.

0:10:20.920,0:10:22.270
It's a lot more complicated,

0:10:22.270,0:10:24.040
there's loads of different species.

0:10:24.040,0:10:29.600
Even here, wherever you draw a line,[br]you find a lot of species coexisting.

0:10:29.600,0:10:32.800
What we have recently found out,[br]in the last year and a half,

0:10:32.800,0:10:35.720
and what actually shocked us[br]as we hadn't been expecting it,

0:10:35.720,0:10:39.040
is that this is true[br]even in very recent times.

0:10:39.040,0:10:40.160
If you look here,

0:10:40.160,0:10:44.200
Homo sapiens is at the top right[br]and we are the last twig, this one.

0:10:44.200,0:10:45.880
This is the present.

0:10:45.880,0:10:51.520
If you just go a little back in time,[br]even only 40/50,000 years,

0:10:51.520,0:10:54.960
you discover that there were[br]other human species on Earth.

0:10:54.960,0:10:57.080
And we have recently found out

0:10:57.080,0:11:02.000
that up to 30, 35, 40,000[br]years ago at most, mind you,

0:11:02.000,0:11:05.920
five human species coexisted on Earth, [br]at the same time.

0:11:05.920,0:11:09.520
That's something we hardly figure out:[br]five different human species!

0:11:09.520,0:11:12.000
If an alien had fallen to Earth[br]40,000 years ago,

0:11:12.000,0:11:14.960
he would have seen us Sapiens

0:11:14.960,0:11:18.760
roam around with four other human forms.

0:11:18.760,0:11:25.033
This, of course, opens up[br]many important and intriguing questions.

0:11:25.600,0:11:27.840
This is one of the latest discoveries,

0:11:27.840,0:11:30.920
made in Indonesia[br]on a small island called Flores.

0:11:30.920,0:11:34.680
We found storks 1.80 m tall,

0:11:34.680,0:11:38.360
mice 1.50 m long, tail included,

0:11:38.360,0:11:42.200
and small Hominini,[br]which hardly ever exceeded 1 m in height.

0:11:42.200,0:11:44.560
This is a relative of ours,[br]a cousin of ours,

0:11:44.560,0:11:46.680
discovered a few years ago on this island

0:11:46.680,0:11:50.000
where it had been stuck[br]for hundreds of thousands of years,

0:11:50.000,0:11:51.600
and had become very short.

0:11:51.600,0:11:55.920
This is an evolutionary mechanism called[br]insular dwarfism and it often occurs.

0:11:55.920,0:11:57.360
It also occurred in Italy.

0:11:57.360,0:11:59.880
As you may know,[br]dwarf elephants lived in Sicily,

0:11:59.880,0:12:02.480
they were as big as a large dog.

0:12:02.480,0:12:04.440
Dwarf mammoths lived in Sardinia.

0:12:04.440,0:12:09.680
This is because when large[br]warm-blooded species get stuck on islands,

0:12:09.680,0:12:13.160
it is better for them to become smaller,[br]in terms of natural selection.

0:12:13.160,0:12:15.184
But incredibly, this is the first time

0:12:15.184,0:12:17.800
that we see this occurring[br]in a human species.

0:12:18.440,0:12:21.080
But even more shockingly,

0:12:21.080,0:12:26.800
so much so that it took us a few years[br]before we actually accepted the fact,

0:12:26.800,0:12:28.259
this specimen here,

0:12:28.259,0:12:31.520
immediately called[br]Hobbit Man, by scientists,

0:12:31.520,0:12:34.480
that Hobbit Man on that island, Flores,

0:12:34.480,0:12:37.720
carried on and survived[br]until 12,000 years ago,

0:12:37.720,0:12:39.080
the day before yesterday.

0:12:39.080,0:12:42.810
At school, almost all of us studied[br]the Egyptians, the Sumerians,

0:12:42.810,0:12:45.320
the civilizations who invented[br]writing, the pyramids.

0:12:45.320,0:12:48.320
Take the pyramids, go back[br]a few thousand years

0:12:48.320,0:12:52.000
and on Earth there was[br]another human species, related to us,

0:12:52.000,0:12:53.600
with whom we coexisted

0:12:53.600,0:12:57.810
and whom we also met[br]as we actually visited that island.

0:12:57.810,0:12:59.380
We know that because Homo Sapiens

0:12:59.380,0:13:03.280
went in Australia[br]long before their extinction.

0:13:03.280,0:13:06.600
And we also know that we met,[br]we saw each other.

0:13:06.600,0:13:12.320
But there have been even more shocking[br]close encounters of the prehistoric type.

0:13:12.320,0:13:16.640
This is the latest discovery;[br]the paper is from April 2010.

0:13:16.640,0:13:22.680
In short, in a cave in the Altai mountains[br]in southern Siberia, on Asia,

0:13:22.680,0:13:26.400
we identified another human species[br]whose existence we had had no inkling of.

0:13:26.400,0:13:31.320
We knew that this cave, the Denisova cave,[br]had already been inhabited by two species:

0:13:31.320,0:13:35.080
we the Sapiens,[br]already 40/50,000 years ago,

0:13:35.080,0:13:38.240
and the famous Neanderthals,[br]we've all studied about at school.

0:13:38.240,0:13:42.010
You know that Neanderthal[br]was not an ancestor of ours,

0:13:42.010,0:13:43.179
he was a cousin of ours.

0:13:43.179,0:13:44.680
We coexisted with him:

0:13:44.680,0:13:47.200
even here in Italy,[br]in these valleys, in these areas

0:13:47.200,0:13:50.540
there were villages inhabited by Sapiens[br]and others by Neanderthals.

0:13:50.540,0:13:54.880
We probably communicated,[br]maybe we even swapped technologies.

0:13:54.880,0:13:57.120
There are sites where[br]sometimes an innovation,

0:13:57.120,0:13:59.560
which had already appeared[br]in a Sapiens settlement,

0:13:59.560,0:14:01.980
was then found in[br]a Neanderthal one and vice versa.

0:14:01.980,0:14:04.120
This shows that there was an interaction.

0:14:04.120,0:14:06.760
Our evolutionary history[br]is checkered with alter egos.

0:14:06.760,0:14:08.120
We have never been alone.

0:14:08.120,0:14:11.160
We've been alone on this planet[br]for a very short time indeed.

0:14:11.160,0:14:14.880
And in that cave,[br]scientists expected to find remains

0:14:14.880,0:14:17.720
of either Sapiens or Neanderthals[br]or possibly both of them.

0:14:17.720,0:14:22.440
They took a little finger,[br]a phalanx, from a skeleton,

0:14:23.280,0:14:26.160
brought it back to Germany[br]and extracted its DNA.

0:14:26.160,0:14:29.800
That can be done today: we don't live[br]in Jurassic Park, but it can be done!

0:14:29.800,0:14:32.440
You extract the DNA[br]and see which species it belongs to.

0:14:32.440,0:14:35.440
It turned out it belonged[br]to neither Sapiens nor Neanderthal

0:14:35.440,0:14:36.840
but to yet another species.

0:14:36.840,0:14:39.760
So a very complex history of coexistence.

0:14:39.760,0:14:43.040
You must be wondering about[br]something that we are all curious about,

0:14:43.040,0:14:48.000
because evolution, Gould said it himself,[br]is a story of death and sex

0:14:48.000,0:14:50.640
and we're always very interested in both.

0:14:50.640,0:14:57.120
Well, we don't know what caused[br]these species to disappear, to die out.

0:14:57.120,0:14:59.160
They all became extinct very recently,

0:14:59.160,0:15:03.960
and I know that you suspect we might[br]have had something to do with this.

0:15:03.960,0:15:06.280
We probably did play a role[br]in their extinction,

0:15:06.280,0:15:09.920
but we don't know exactly how,[br]as nothing dramatic happened.

0:15:09.920,0:15:12.320
We can state for sure,[br]it was not a genocide.

0:15:12.320,0:15:14.030
We did not kill them off directly.

0:15:14.040,0:15:18.560
Something else must have happened[br]that led to their progressive regression.

0:15:18.560,0:15:19.960
The fact is that, recently,

0:15:19.960,0:15:22.650
we became the only human species[br]left on the planet.

0:15:22.650,0:15:26.600
Then there is the sex side[br]and this is also surprising.

0:15:26.600,0:15:28.040
Up to a few months ago

0:15:28.040,0:15:31.680
I would have told you that[br]different species could not interbreed.

0:15:31.680,0:15:33.960
We thought there was a genetic barrier.

0:15:33.960,0:15:37.120
But the last discovery we made[br]proved that this was not the case.

0:15:37.120,0:15:40.640
Actually, all non-African Sapiens,

0:15:40.640,0:15:43.760
that is those who came out of Africa[br]and remained out of Africa,

0:15:43.760,0:15:49.440
probably have a 4 to 6% proportion[br]of Neanderthal traces in their blood.

0:15:49.440,0:15:53.800
So we carry some traces[br]of Neanderthal DNA in our blood.

0:15:53.800,0:15:55.840
How is that possible?

0:15:55.840,0:16:00.200
The only explanation, or at any rate,[br]the most plausible explanation

0:16:00.200,0:16:04.070
is that at least at some time in the past,[br]possibly in the Middle East for some,

0:16:04.070,0:16:06.640
for 10/15 thousand years[br]we may have mated.

0:16:06.640,0:16:11.960
We had fertile matings,[br]so the two species interbred for a while,

0:16:11.960,0:16:17.800
then they separated, one of them died out[br]and we Sapiens had the upper hand.

0:16:17.800,0:16:23.000
But this is a dogma that is refuted[br]because our genome is not only ours,

0:16:23.000,0:16:24.840
so we must not be too jealous.

0:16:24.840,0:16:26.449
It is a cloak of Harlequin

0:16:26.449,0:16:29.280
in which there are traces[br]of other species.

0:16:29.280,0:16:32.480
We are not alone, not even in our genome.

0:16:32.480,0:16:35.340
I'm now showing you this image[br]because we came out of here.

0:16:35.340,0:16:38.240
This is another very recent fact:[br]the strait of Djibouti.

0:16:38.240,0:16:41.680
Populations of the Sapiens[br]crossed this small passage,

0:16:41.680,0:16:45.840
and then met the other species[br]that had left earlier:

0:16:45.840,0:16:49.280
the Neanderthals, the Denisovans[br]I have just shown you,

0:16:49.280,0:16:52.120
and then the Indonesian species.

0:16:52.120,0:16:55.040
This is a summary[br]of everything I have told you:

0:16:55.040,0:16:56.350
we ventured out of Africa,

0:16:56.350,0:16:59.960
we did so repeatedly[br]from 100/120,000 years ago

0:16:59.960,0:17:03.920
and when we came out,[br]we met other existing living forms,

0:17:03.920,0:17:05.560
human species related to us.

0:17:05.560,0:17:10.920
We coexisted, we sometimes mated[br]and then we colonized the whole world.

0:17:10.920,0:17:12.510
We're the only one, for example,

0:17:12.510,0:17:15.340
who arrived in Australia[br]and then colonized the Americas,

0:17:15.340,0:17:18.040
because in the ice ages[br]the world was different

0:17:18.040,0:17:19.850
from what it appears to be like here.

0:17:19.850,0:17:22.990
There were entire continents[br]that are now submerged, like Beringia,

0:17:22.990,0:17:26.240
or this whole area which was passable.

0:17:26.240,0:17:30.320
So you could get there[br]without crossing the sea

0:17:30.320,0:17:33.680
from South Africa to South America.

0:17:33.680,0:17:37.160
One of the consequences, of course,[br]of this whole story

0:17:37.160,0:17:38.310
is, first, that perhaps

0:17:38.310,0:17:41.280
we need to look at evolution[br]with a little more humility,

0:17:41.280,0:17:44.520
without thinking of ourselves[br]as the ultimate end,

0:17:44.520,0:17:46.979
especially since we interbred.

0:17:46.979,0:17:48.190
And interestingly,

0:17:48.190,0:17:51.910
but I'm saying it only now, in closing,[br]because I didn't want to shock anyone,

0:17:51.910,0:17:54.780
we also know that the interbreeding[br]was asymmetrical.

0:17:54.780,0:17:57.960
It was always a Neanderthal male[br]with a Sapiens female.

0:17:57.960,0:18:00.640
That for us Sapiens boys[br]is really disheartening

0:18:00.640,0:18:01.800
(Laughter)

0:18:01.800,0:18:04.980
because we had our females[br]stolen from us 40,000 years ago already,

0:18:04.980,0:18:07.760
so evolution punched us in the stomach.

0:18:07.760,0:18:09.979
But the second consequence[br]is more serious:

0:18:09.979,0:18:12.360
if this is our history,

0:18:12.360,0:18:15.760
then what we have always called[br]"human races" do not actually exist.

0:18:15.760,0:18:17.480
We are a young species,

0:18:17.480,0:18:19.410
we all come from a very small group

0:18:19.410,0:18:22.200
and there was no time[br]to separate human races.

0:18:22.200,0:18:26.800
So let's delete the concept of human race[br]from the language of science.

0:18:26.800,0:18:27.960
Thank you!

0:18:27.960,0:18:28.960
(Applause)