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Practice English Speaking&Listening with: Newly discovered Aboriginal genome study rewrites history | Research breakthroughs at Murdoch Uni

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Well, I come here because we have that

press release tomorrow, of the first

Aboriginal Australian genome, and so we

have we have a paper and press in

science saying something about what

this genome cells about early modern

human dispersal. It actually changes our

view on on the early dispersal of modern

man, in the sense that that previously

the general notion was that there was

one expansion, you know eastwards, so to

speak, that conquered the world. And from

that expansion, you know, different groups

popped out. First Europeans, later Asians,

and from within the Asian cluster, then

Aboriginal Australians kind of moved

down to Australia. And now we can show

that it's probably not what happened.

There was in fact at least two early

expansions eastwards. So the first one is,

this you know, the ancestors of

Aboriginal Australians already expanding

into the world some 70,000 years ago. At

that time our ancestors, I mean

European and Asian ancestors

were sitting somewhere in Africa and the

Middle East, not really daring entering

the world. But these guys was just

crossing all the way to Australia and

then some 30,000 years later our

ancestors start moving. Some move into

Europe, some move into Asia, and the

Asians then meet, you can say, the

remnants of the first expansion. In

probably some places in Asia and they

intermixed with those guys and that's

the reason why genetically speaking,

Aboriginal Australians and Asians are more

similar today than Aborigine Australians

and Europeans for example. So, we have

used a hair sample that was collected by

an British anthropologist in the early

1920s and we used this

sample, it's from South Western Australia,

and the whole idea of using the sample

was to try to increase the chances of

getting an unadmixed, I mean

recently, you can say, a genome without recent European admixture.

And also, you can say, to explore the possibility

whether you can actually obtain genome

sequences from such museum collections. I

mean from you can say historical ancient

material, because that would open an

avenue for exploring the genetics

and the history of populations that have

either been heavily admixed recently or

have gone extinct, where you have

hair from. And this is also what we find,

there's no evidence of recent European

admixture in in the genome, and we use

hair, because here is not porous or

anything like that, so all contamination

from all the people who have handled

this here over the years is all sitting

on the surface, so by bleaching it you

can actually remove all the

contamination, so you have the only the

endogenous DNA.

Bone and teeth are porous and it means the

contamination both in the form of

microbes, but also people who

have handled the specimens, actually

penetrating very deep into bones and

teeth. While with hair, it's actually a kind of

like a plastic surface, I mean it's all

lying on the outside, so it's very easy

to remove. So, even though hair, you can

say per gram of material, contains much

less DNA than bone and teeth normally,

you can get a much

cleaner result. Essentially what we're

doing is trying to isolate all the DNA

away from all the other components and

from biological material. Now, all

biological material contains DNA to some

extent and as archeogeneticists DNA

specialists we isolate the DNA away

from all the cellular components, things

like fats and proteins that are that are

inside the hair shaft. We isolate that

DNA away, we smash it up into lots of

little pieces and then we shotgun

sequence it, which means we randomly

sequence every single piece of these

small fragments. And then the billion

piece jigsaw comes into play, where we

try and piece it all together to make a

comprehensive picture. So, that's what the

new technology that we're putting

forward here is about essentially, as

using new sequencing technology

to look at old samples. As people sort of

move or have moved across the globe and

even live in on and signal places and

populations intermingle

and their DNA changes over time, and they

leave behind sort of genetic breadcrumbs,

if you like, and what we do when we get

the genetic code is were able to

actually look at these pieces of DNA, how

they've changed, similarities and

differences and look at intermingling. So,

we can go from the genetic code through

to some inference about what populations

were doing over time and how they moved.

We've had a long time known that

Aboriginal people been in Australia for

40,000 - now we know - 50,000 years.

So, archaeological evidence has told us

that. What this tells us is that it's been

even longer and we've had great

difficulty in extending back that

time frame. Some inkling that maybe there

was some, there's two sites possibly

dated to 60,000, but they remain

controversial and we haven't been able

to duplicate them. So, this is now giving

us indication that people have been here,

or at least separated from other groups for

70,000 years perhaps. And so now we have

a time frame that's much older.

Australia has always been isolated, as we

all know, and we've got unique fauna and

it's also got this incredibly difficult

sea crossing between it and Asia. So,

people must have had incredible amount

of foresight, planning, communications and

ability to conceptualize things. That is

there were modern people though, just

like us. So we know from archaeological

evidence, that whoever got here, it's one

of the earliest achievements of modern

humans, if you like, to get to Australia.

But now we've pushed that achievement

back from 50,000 to 70,000. In the

South West of WA we've been working

on, my dad Charlie Dortch started this

work in the 1970s at Devil's Lair, which

has got one of the longest sequences of

cave occupation or occupation of any

site in Australia, so that that began at

about 47 to 49 thousand years ago. I was

part of a team in the 1990s where we

re-dated the sediments using

luminescence techniques, a new method

of dating. That site is pretty well dated

and it'd be a fantastic resource for

looking at, it continues to be a

fantastic resource, for looking at human

occupation. Well I think if we can

recover human DNA from there and working

with the traditional owners in the area

as we have is this current project we

will hopefully be able to recover enough

human DNA

to look at how people have arrived

and you know where they came from and so

on in that area. And that aside there is also

of course plant and animal DNA in those

sediments which would be incredibly

interesting. We began that research because,

you know, the Aboriginal people of the

region that this sample came from

obviously have cultural concerns. The

hair sample has cultural values, well

aside from a scientific value, and so

they were concerned firstly, about how

the sample was collected and then you

know they had current contemporary

concerns about the research that was

being done on the hair sample. So, I did

some research into how the sample is

collected first of all and found that it

was taken by the Cambridge

anthropologist Alfred Hadden, who caught

the Trans-Australia Line across the

country in 1923 and stopped at a small

centre called Golden Ridge, just outside

of Kalgoorlie, where he really would have

only had the opportunity to collect the

sample in a voluntary exchange.

Aboriginal people were at that time

trading artifacts and so on for food and

money along the Trans Line and

obviously this was a little bit more

unusual transaction, but someone

gave up a hair sample and received

whatever in return from Hadden, and

that's how the sample found its way to

Cambridge University. When the the

Goldfields Land and Sea Council, which

represents the Aboriginal people of the

region, when they learned about this

research they had some concerns about it,

so you know, I did that research

into the origins of the sample and then

Professor Willerslev came to Western

Australia in June 2011 to discuss his

research with the board, which, you know

was greatly appreciated, the respect that

was shown and so on, and the board, which

as I say, represents the people of the

region gave their unqualified

endorsement. There's a lot of

interest in the results, although not

everyone accepts that the scientific

discourse is the only explanation for

people's origins in the desert and elsewhere.

But there was no

qualifications on having the

research done.

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