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