Digging for humanitys origins Louise Leakey
who are we that is the big question
and essentially we are just an upright
walking big brain super intelligent ape
this could be us we belong to the family
called the humanity we are the species
called Homo sapiens sapiens and it’s
important to remember that and in terms
of our place in the world today and our
future and planet Earth
we are one species of about five and a
half thousand mammalian species that
exist on planet Earth today and that’s
just a tiny fraction of all species that
have ever lived on the planet in past
times we’re one species out of
approximately one let’s say at least
sixteen upright-walking apes that have
existed over the past six to eight
million years but as far as we know
we’re the only upright-walking ape that
exists on planet Earth today except for
the bonobos and it’s important to
remember that because the bonobos are so
human and they share 99% of their genes
with us and we share our origins with a
handful of the living great apes it’s
important to remember that we evolved
now I know that’s a dirty word for some
people but we evolved from common
ancestors with the gorillas the
chimpanzee and also the bonobos we have
a common past and we have a common
future and it is important to remember
that all of these great apes have come
on as long and as an interesting
evolutionary journey as we ourselves
have today and it’s this journey that is
of such interest to humanity and it’s
this journey that has been the focus of
the past three generations of my family
as we’ve been in East Africa looking for
the fossil remains of our ancestors to
try and piece
together our evolutionary past and this
is how we look for them a group of
dedicated young men and women walk very
slowly off across vast areas of Africa
looking for small fragments of bone
fossil bone that may be on the surface
and that’s an example of what we may do
as we walk across the landscape in
northern Kenya looking for fossils I
thought many of you in the audience can
see the fossil that’s in this picture
but if you look very carefully there is
a jaw no a jaw of a 4.1 million year old
upright walking ape as it was found at
Lake Turkana on the west side it’s
extremely time consuming labor-intensive
and it is something that it’s going to
involve a lot more people to begin to
piece together our paths we still really
haven’t got a very complete picture of
it when we find a fossil we market today
we’ve got great technology we have GPS
we mark it with a GPS fix and we also
take a digital photograph of the
specimen so we could essentially put it
back on the surface exactly where we
found it and we can bring all this
information into big GIS packages today
when we then find something very
important like the bones of a human
ancestor we begin to excavate it
extremely carefully and slowly using
dental picks and fine paintbrushes and
all the sediment is then put through
these screens and where we go again
through it very carefully looking for
small bone fragments and it’s been
washed and these things are so exciting
they are so often the only or the very
first time that anybody has ever seen
the remains and here is a very special
moment when my mother and myself were
digging up and some remains of human
human ancestors and it isn’t one of the
most special things to ever do with your
mother
cannot many people look and say that but
now let me take you back to Africa two
million years ago I just like to point
out if you look at the map of Africa it
does actually look like a hominid skull
in its shape now we’re going to go to
the East African and the Rift Valley
essentially runs up from the Gulf of
Aden or runs down to Lake Malawi and the
Rift Valley is a depression it’s a basin
and rivers flowed down from the
highlands into the basin carrying
sediment preserving the bones of animals
that live there if you want to become a
fossil you actually need to die
somewhere where your bones will be
rapidly buried you then hope that the
earth moves in such a way as to bring
the bones back up to the surface and
then you hope that one of us lot will
walk around and find small pieces of you
okay so it is absolutely surprising that
we know as much as we do know today
about our ancestors because it’s
incredibly difficult eh for these things
to become to be preserved and secondly
for them to have been brought back up to
the surface and we really have only
spent fifty years looking for these
remains and begin to actually piece
together our evolutionary story so
that’s good too Lake Turkana which is
one such Lake basin in the very north of
our country Kenya and if you look north
here there’s a big river that flows into
the lake that’s been carrying sediment
and preserving the remains of the
animals that live there fossil sites run
up and down both lengths of that lake
basin which represents some twenty
thousand square miles that’s a huge job
that we’ve got on our hands two million
years ago at Lake Turkana Homo erectus
one of our human ancestors actually
lived in this region you can see some of
the major fossil sites that we’ve been
working in the north but essentially
two million years ago Homo erectus up in
the far right corner lived alongside
three other species of human ancestor
and here is a skull of a homo erectus
which have just pulled off the shelf
there but it is not to say that being a
single species on planet Earth is the
norm in fact if you go back in time it
is the norm that there are multiple
species of hominids of human ancestors
that coexist at any one time where did
these things come from that’s what we’re
still trying to find answers to and it
is important to realize that there is
diversity in all different species and
our ancestors are no exception there’s
some reconstructions of some of the
fossils that have been found from Lake
Turkana but I was very lucky to have
been brought up in Kenya essentially
accompanying my parents to Lake Turkana
in search of human remains and we were
able to dig up when we got old enough
fossils such as this a slender snouted
crocodile and we dug up giant tortoises
and elephants and things like that but
when I was 12 as I was in this picture a
very exciting expedition was in place on
the west side when they found
essentially the skeleton of this Homo
erectus I could relate to this Homo
erectus skeleton very well because I was
the same age that he was when he died
and I imagined him to be tall dark
skinned his brother certainly were able
to run long distances chasing prey
probably sweating heavily as they did so
he was very able to use stones
effectively as tools and this individual
himself this one that I’m holding up
here actually had a bad back he probably
had an injury as a child he
the scoliosis and therefore must have
been looked after quite carefully by
other female and probably much smaller
members of his family group to have got
to where he did in life age 12
unfortunately for him he fell into a
swamp and was and couldn’t get out
essentially his bones were rapidly
buried and beautifully preserved and he
remained there until 1.6 million years
later when this very famous fossil
hunter Camille Camille walked along a
small hillside and found that small
piece of his skull lying on the surface
amongst the pebbles recognized it as as
being hominid it it’s actually this
little piece up here on the top well an
excavation was begun immediately and
more and more little bits of skull
started to be extracted from the
sediment and what was so fun about it
was the skull pieces got closer and
closer to the roots of the tree and
fairly recently the tree had grown up
but it had found that the skull had
captured nice water in the hillside and
so it had decided to grow its roots in
and around this holding it in place and
preventing it from washing away down the
slope we began to find limb bones we
found finger bones the bones of the
pelvis vertebrae ribs collarbones things
that had never ever been seen before and
in Homo erectus
it was truly exciting he had a body very
similar to our own and he was on the
threshold of becoming human
well it’s shortly afterwards members of
his species started to move northwards
out of Africa and you start to see
fossils of Homo erectus in Georgia and
China and also in parts of Indonesia so
Homo erectus was the first human
ancestor to leave Africa and begin its
spread across the globe
some exciting finds again as I mentioned
from Dmanisi in the Republic of Georgia
but also surprising finds from recently
announced from the island of Flores in
Indonesia where a group of these human
ancestors have been isolated and have
become dwarfed and they’re only about a
metre in height but they lived only
18,000 years ago and that is truly
extraordinary to think about just to put
this in terms of generations because
people do find it hard to think of time
Homo erectus left Africa 90,000
generations ago we evolved essentially
from an African stock again at about
200,000 years as a fully fledged us and
we only left Africa about 70,000 years
ago and until 30,000 years ago at least
three upright-walking its shared the
planet earth the question now is for who
who are we were certainly a polluting
wasteful aggressive species with a few
nice things thrown in perhaps for the
most part but you’re not particularly
pleasant at all we have a much larger
brain than our ape ancestors is this a
good evolutionary adaptation or is it
going to lead us to being the shortest
lived hominid species on planet earth
and what is it that really makes us us I
think it’s our collective intelligence
it’s our ability to write things down
our language and our consciousness from
very primitive beginnings with a very
crude toolkit of stones we now have a
very advanced toolkit and our tool use
has really reached unprecedented levels
we’ve got buggies to Mars we’ve mapped
the human genome and recently even
created synthetic life thanks to craig
Venter and we’ve also managed to
communicate with people all over the
world from extraordinary places even
from within an excavation in northern
Kenya we can talk to people
about what we’re doing as albor so
clearly has reminded us we have reached
extraordinary numbers of people on this
planet human ancestors really only
survive on planet Earth if you look at
the the fossil record for about on
average a million years at a time we’ve
only been around for the past 200
thousand years as a species yet we’ve
reached a population of more than six
and a half billion people and last year
our population grew by 80 million I mean
these are extraordinary numbers you can
see here again taken from Al Gore’s book
but what’s happened is our technology
has removed the checks and balances on
our population growth we have to control
our numbers and I think this is as
important as anything else that’s being
done in the world today but we have to
control our numbers because we can’t
really hold it together as a species my
father so appropriately put it that we
are certainly the only animal that makes
conscious choices that are bad for our
survival as a species can we hold it
together it’s important to remember that
we all evolved in Africa we all have an
African origin we have a common past and
we share a common future evolutionary
speaking we’re just a blip we’re sitting
on the edge of a precipice we have the
tools and the technology at our hands to
communicate what needs to be done to
hold it together today we could tell
every single human being out there if we
really wanted to but will we do that or
will we just let nature take its course
well to end on a very positive note I
think evolutionary speaking this is
probably a fairly good thing in the end
I’ll leave it at that thank you very
much
you