Svante Pääbo: DNA clues to our inner neanderthal

Prevodilac: Ivana Gadjanski Lektor: Ivana Korom

What I want to talk to you about

Ono o čemu želim da vam govorim

is what we can learn from studying the genomes

je ono što možemo da saznamo proučavajući genome

of living people

živih ljudi

and extinct humans.

i izumrlih ljudi.

But before doing that,

Ali, pre nego što to uradim,

I just briefly want to remind you about what you already know:

želim samo kratko da vas podsetim na nešto što već znate:

that our genomes, our genetic material,

da su naši genomi, naš genetički materijal,

are stored in almost all cells in our bodies in chromosomes

uskladišteni u skoro svim ćelijama naših tela u hromozomima

in the form of DNA,

u obliku DNK,

which is this famous double-helical molecule.

što je čuveni molekul u obliku dvostruke spirale.

And the genetic information

I da se genetička informacija

is contained in the form of a sequence

nalazi u obliku sekvence

of four bases

od četiri baze

abbreviated with the letters A, T, C and G.

koje se skraćeno označavaju slovima A, T, C i G.

And the information is there twice --

I ta informacija je tu u duplikatu -

one on each strand --

po jedna na svakom lancu DNK -

which is important,

što je važno,

because when new cells are formed, these strands come apart,

jer, kada se formiraju nove ćelije, ovi lanci se razdvajaju

new strands are synthesized with the old ones as templates

novi lanci se sintetišu koristeći stare lance kao obrasce

in an almost perfect process.

tokom jednog skoro savršenog procesa.

But nothing, of course, in nature

Ali, naravno, ništa u prirodi

is totally perfect,

nije potpuno savršeno,

so sometimes an error is made

tako da se ponekad desi greška

and a wrong letter is built in.

i ugradi se pogrešno slovo.

And we can then see the result

I možemo videti rezultat

of such mutations

takvih mutacija

when we compare DNA sequences

kada uporedimo DNK sekvence

among us here in the room, for example.

na primer između svih nas u ovoj sali.

If we compare my genome to the genome of you,

Ako uporedimo moj genom sa vašim genomom,

approximately every 1,200, 1,300 letters

otprilike svakih 1.200, 1.300 slova

will differ between us.

će se razlikovati među nama.

And these mutations accumulate

I ove mutacije se nagomilavaju

approximately as a function of time.

može se reći da postoji vremenska zavisnost.

So if we add in a chimpanzee here, we will see more differences.

A ako tu ubacimo šimpanzu, videćemo više razlika.

Approximately one letter in a hundred

Otprilike jedno slovo na svakih sto

will differ from a chimpanzee.

će se razlikovati od šimpanzinog.

And if you're then interested in the history

I onda, ako vas interesuje istorija

of a piece of DNA, or the whole genome,

komadića DNK ili celog genoma,

you can reconstruct the history of the DNA

možete da rekonstruišete istoriju DNK

with those differences you observe.

koristeći te razlike koje ste uočili.

And generally we depict our ideas about this history

I obično predstavljamo naše ideje o toj istoriji

in the form of trees like this.

u obliku ovakvih razgranatih dijagrama.

In this case, it's very simple.

U ovom slučaju je vrlo jednostavno.

The two human DNA sequences

Ove dve ljudske DNK sekvence

go back to a common ancestor quite recently.

idu unazad do zajedničkog pretka u skorijoj prošlosti.

Farther back is there one shared with chimpanzees.

Još više unazad je predak kojeg dele sa šimpanzama.

And because these mutations

I budući da ove mutacije

happen approximately as a function of time,

uglavnom imaju vremensku zavisnost,

you can transform these differences

možete transformisati ove razlike

to estimates of time,

u procene vremenskih perioda,

where the two humans, typically,

pri čemu će dve ljudske vrste, tipično

will share a common ancestor about half a million years ago,

imati zajedničkog pretka od pre oko pola miliona godina,

and with the chimpanzees,

dok će sa šimpanzama,

it will be in the order of five million years ago.

to biti reda veličine od pet miliona godina.

So what has now happened in the last few years

Dakle, ono što se dešava u poslednjih nekoliko godina

is that there are account technologies around

je da postoje tehnologije za procenu koje

that allow you to see many, many pieces of DNA very quickly.

nam omogućavaju da, vrlo brzo vidimo mnogo, mnogo komadića DNK.

So we can now, in a matter of hours,

Pa tako sada možemo da, za nekoliko sati,

determine a whole human genome.

odredimo ceo ljudski genom.

Each of us, of course, contains two human genomes --

Svako od nas, naravno, sadrži dva humana genoma -

one from our mothers and one from our fathers.

jedan od majke i drugi od oca.

And they are around three billion such letters long.

I njihova dužina je oko tri milijarde ovakvih slova.

And we will find that the two genomes in me,

I otkrićemo da dva genoma u meni

or one genome of mine we want to use,

ili jedan moj genom koji želimo da koristimo,

will have about three million differences

ima oko tri miliona razlika

in the order of that.

tog reda veličina.

And what you can then also begin to do

I zatim, ono što takođe može da se radi

is to say, "How are these genetic differences

je da se vidi kako su te genetičke razlike

distributed across the world?"

distribuirane širom sveta.

And if you do that,

I ako to uradite,

you find a certain amount of genetic variation in Africa.

otkrićete određen broj genetičkih varijacija u Africi.

And if you look outside Africa,

A ako pogledate van Afrike,

you actually find less genetic variation.

zapravo ćete naći manje genetičkih varijacija.

This is surprising, of course,

To je, naravno, iznenađujuće,

because in the order of six to eight times fewer people

jer, oko šest do osam puta manje ljudi

live in Africa than outside Africa.

živi u Africi nego van Afrike.

Yet the people inside Africa

A ipak, ljudi u Africi

have more genetic variation.

imaju više genetičkih varijacija.

Moreover, almost all these genetic variants

Štaviše, skoro sve ove genetičke varijante

we see outside Africa

koje nalazimo van Afrike

have closely related DNA sequences

imaju DNK sekvence koje su blisko povezane

that you find inside Africa.

sa onima koje se nalaze u Africi.

But if you look in Africa,

Ali, ako posmatrate unutar Afrike,

there is a component of the genetic variation

postoji komponenta genetičke varijacije

that has no close relatives outside.

koja nema bliske srodnike van Afrike.

So a model to explain this

Dakle, model koji ovo objašnjava

is that a part of the African variation, but not all of it,

je, da je jedan deo, ali ne i celokupna afrička varijacija,

[has] gone out and colonized the rest of the world.

izašao i kolonizovao ostatak sveta.

And together with the methods to date these genetic differences,

I zajedno sa metodama za datiranje genetičkih razlika,

this has led to the insight

ovo je dovelo do zaključka

that modern humans --

da su moderni ljudi -

humans that are essentially indistinguishable from you and me --

ljudi koji se praktično ne mogu razlikovati od vas i mene -

evolved in Africa, quite recently,

evoluirali u Africa u vrlo skoroj prošlosti

between 100 and 200,000 years ago.

pre oko 100 i 200.000 godina.

And later, between 100 and 50,000 years ago or so,

I kasnije su, pre oko približno 100 i 50.000 godina

went out of Africa

izašli iz Afrike

to colonize the rest of the world.

da kolonizuju ostatak sveta.

So what I often like to say

Dakle, ono što ja često volim da kažem

is that, from a genomic perspective,

je da smo, iz genomske perspektive,

we are all Africans.

mi svi Afrikanci.

We either live inside Africa today,

Sada, ili živimo u Africi,

or in quite recent exile.

ili smo u egzilu koji je nedavno počeo.

Another consequence

Još jedna posledica

of this recent origin of modern humans

ovog ne tako davnog porekla modernih ljudi

is that genetic variants

je da su genetičke varijante

are generally distributed widely in the world,

obično široko rasprostranjene širom sveta,

in many places,

na mnogo mesta,

and they tend to vary as gradients,

i imaju tendenciju da variraju u vidu gradijenata,

from a bird's-eye perspective at least.

bar kad se posmatra iz ptičje perspektive.

And since there are many genetic variants,

I budući da postoji mnogo genetičkih varijanti,

and they have different such gradients,

i da se njihovi gradijenti razlikuju,

this means that if we determine a DNA sequence --

sledi zaključak da, ako odredimo DNK sekvencu -

a genome from one individual --

genom jednog pojedinca -

we can quite accurately estimate

možemo vrlo pouzdano da procenimo

where that person comes from,

odakle je ta osoba,

provided that its parents or grandparents

uz uslov da se roditelji te osobe, kao i njihovi roditelji

haven't moved around too much.

nisu suviše često selili.

But does this then mean,

Ali, da li ovo sada znači,

as many people tend to think,

kao što mnogo ljudi ima tendenciju da smatra,

that there are huge genetic differences between groups of people --

da postoje ogromne genetičke razlike između grupa ljudi -

on different continents, for example?

na primer, na različitim kontinentima?

Well we can begin to ask those questions also.

Pa, možemo početi da postavljamo i takva pitanja.

There is, for example, a project that's underway

Postoji, na primer, projekat koji je na putu

to sequence a thousand individuals --

da sekvencionira hiljadu pojedinaca -

their genomes -- from different parts of the world.

njihove genome - iz različitih delova sveta.

They've sequenced 185 Africans

Do sada su sekvencionirali 185 Afrikanaca

from two populations in Africa.

iz dve populacije u Africi.

[They've] sequenced approximately equally [as] many people

Sekvencionirali su približno isto toliko ljudi

in Europe and in China.

u Evropi i u Kini.

And we can begin to say how much variance do we find,

I možemo početi da govorimo koliko variranja je nađeno,

how many letters that vary

koliko slova varira

in at least one of those individual sequences.

u bar jednoj od tih pojedinačnih sekvenci.

And it's a lot: 38 million variable positions.

I to je mnogo: 38 miliona varijabilnih pozicija.

But we can then ask: Are there any absolute differences

Ali, možemo pitati: da li postoje neke apsolutne razlike

between Africans and non-Africans?

između Afrikanaca i ne-Afrikanaca?

Perhaps the biggest difference

Možda i najveća razlika

most of us would imagine existed.

koju većina nas može da zamisli zaista postoji.

And with absolute difference --

I kad kažem "apsolutna razlika" -

and I mean a difference

pod tim mislim razlika

where people inside Africa at a certain position,

pri kojoj ljudi u Africi, na određenoj poziciji,

where all individuals -- 100 percent -- have one letter,

pri kojoj svi pojedinci - 100 procenata - imaju jedno slovo,

and everybody outside Africa has another letter.

a svi drugi van Afrike imaju neko drugo slovo.

And the answer to that, among those millions of differences,

I odgovor na to je da, od svih tih miliona razlika,

is that there is not a single such position.

nema nijedne takve pozicije.

This may be surprising.

To može biti iznenađujuće.

Maybe a single individual is misclassified or so.

Možda je jedan pojedinac pogrešno klasifikovan ili tako nešto.

So we can relax the criterion a bit

Pa možemo da malo spustimo kriterijum

and say: How many positions do we find

i da kažemo: Koliko pozicija možemo naći

where 95 percent of people in Africa have

gde 95 procenata ljudi u Africi

one variant,

ima jednu varijantu,

95 percent another variant,

a 95 procenata drugu varijantu,

and the number of that is 12.

i taj broj iznosi 12.

So this is very surprising.

I to je veoma iznenađujuće.

It means that when we look at people

To znači da, kada ispitujemo ljude

and see a person from Africa

i uočimo osobu iz Afrike

and a person from Europe or Asia,

i osobu iz Evrope ili Azije,

we cannot, for a single position in the genome with 100 percent accuracy,

ne možemo, ni za jednu poziciju u genomu sa 100-procentnom sigurnošću,

predict what the person would carry.

predvideti šta će ta osoba nositi.

And only for 12 positions

I samo za 12 pozicija

can we hope to be 95 percent right.

se možemo nadati da budemo 95 procenata u pravu.

This may be surprising,

To može biti iznenađujuće,

because we can, of course, look at these people

jer možemo, naravno, pogledati te ljude

and quite easily say where they or their ancestors came from.

i sasvim lako reći odakle potiču oni ili njihovi preci.

So what this means now

To, dakle, znači da

is that those traits we then look at

te osobine koje tada posmatramo

and so readily see --

i tako lako uočavamo -

facial features, skin color, hair structure --

crte lica, boja kože, struktura kose -

are not determined by single genes with big effects,

nisu određene pojedinačnim genima sa velikim efektima,

but are determined by many different genetic variants

već ih određuje mnogo različitih genetičkih varijanti

that seem to vary in frequency

koje izgleda imaju različitu zastupljenost

between different parts of the world.

u različitim delovima sveta.

There is another thing with those traits

Postoji još jedna stvar sa tim osobinama

that we so easily observe in each other

koje tako lako primećujemo jedni na drugima

that I think is worthwhile to consider,

koju smatram da je korisno da razmotrimo,

and that is that, in a very literal sense,

i to je da su, u vrlo bukvalnom smislu,

they're really on the surface of our bodies.

te osobine, u stvari, samo na površini tela.

They are what we just said --

Te osobine su ono što smo upravo rekli -

facial features, hair structure, skin color.

crte lica, struktura kose, boja kože,

There are also a number of features

Postoji takođe i određen broj osobina

that vary between continents like that

koje variraju između kontinenata i imaju veze

that have to do with how we metabolize food that we ingest,

sa tim kako metabolišemo hranu koju unosimo,

or that have to do

ili sa tim

with how our immune systems deal with microbes

kako se naš imuni sistem nosi sa mikrobima

that try to invade our bodies.

koji pokušavaju da osvoje naša tela.

But so those are all parts of our bodies

Ali, to su sve delovi tela

where we very directly interact with our environment,

preko kojih mi vrlo direktno interagujemo sa okruženjem,

in a direct confrontation, if you like.

u direktnom sučeljavanju, može se reći.

It's easy to imagine

Lako je zamisliti

how particularly those parts of our bodies

da su posebno ti delovi naših tela

were quickly influenced by selection from the environment

bili brzo uobličavani putem selekcije iz okruženja

and shifted frequencies of genes

i da je to pomerilo učestalost gena

that are involved in them.

koji su povezani sa njima.

But if we look on other parts of our bodies

Ali, ako pogledamo druge delove tela

where we don't directly interact with the environment --

koji nisu u direktnom kontaktu sa okruženjem -

our kidneys, our livers, our hearts --

naši bubrezi, jetra, naše srce -

there is no way to say,

ne postoji način da se kaže,

by just looking at these organs,

samo gledanjem na ove organe,

where in the world they would come from.

iz kog dela sveta potiču.

So there's another interesting thing

Dakle, postoji druga interesantna stvar

that comes from this realization

koja sledi iz ovog shvatanja

that humans have a recent common origin in Africa,

da ljudi imaju nedavno zajedničko poreklo u Africi,

and that is that when those humans emerged

a to je da, kada su se ti ljudi pojavili

around 100,000 years ago or so,

pre oko 100.000 godina,

they were not alone on the planet.

nisu bili sami na planeti.

There were other forms of humans around,

Postojale su druge forme ljudi

most famously perhaps, Neanderthals --

najčuveniji su, verovatno, Neandertalci --

these robust forms of humans,

te robusne forme ljudi,

compared to the left here

ovde sa leve strane, u poređenju

with a modern human skeleton on the right --

sa modernim ljudskim skeletom sa desne strane -

that existed in Western Asia and Europe

koja je postojala u zapadnoj Aziji i Evropi

since several hundreds of thousands of years.

od pre nekoliko stotina hiljada godina.

So an interesting question is,

Dakle, zanimljivo pitanje je,

what happened when we met?

šta se desilo kada smo se sreli?

What happened to the Neanderthals?

Šta se desilo sa Neandertalcima?

And to begin to answer such questions,

I da bismo počeli da odgovaramo na takva pitanja,

my research group -- since over 25 years now --

moja istraživačka grupa - već više od 25 godina -

works on methods to extract DNA

radi na metodama ekstrakcije DNK

from remains of Neanderthals

iz ostataka Neandertalaca

and extinct animals

i izumrlih životinja

that are tens of thousands of years old.

starih desetine hiljada godina.

So this involves a lot of technical issues

To uključuje veliki broj tehničkih detalja

in how you extract the DNA,

o tome kako se izoluje DNK,

how you convert it to a form you can sequence.

kako se konvertuje u oblik koji može da se sekvencionira.

You have to work very carefully

Morate raditi vrlo pažljivo

to avoid contamination of experiments

da biste izbegli kontaminaciju eksperimenta

with DNA from yourself.

svojom sopstvenom DNK.

And this then, in conjunction with these methods

I zahvaljujući ovome, zajedno sa onim metodama

that allow very many DNA molecules to be sequenced very rapidly,

koje omogućavaju da veoma mnogo DNK molekula

može vrlo brzo da se sekvencionira,

allowed us last year

smo prošle godine

to present the first version of the Neanderthal genome,

uspeli da pokažemo prvu verziju neandertalskog genoma,

so that any one of you

pa tako bilo ko od vas

can now look on the Internet, on the Neanderthal genome,

može da pogleda na Internetu i nađe neandertalski genom,

or at least on the 55 percent of it

ili bar 55 procenata tog genoma

that we've been able to reconstruct so far.

što smo do sada uspeli da rekonstruišemo.

And you can begin to compare it to the genomes

I može početi da ga upoređuje sa genomima

of people who live today.

ljudi koji žive danas.

And one question

I jedno pitanje

that you may then want to ask

koje ćete možda želeti da postavite

is, what happened when we met?

je, šta se desilo kada smo se sreli?

Did we mix or not?

Jesmo li se mešali ili nismo?

And the way to ask that question

I način na koji to pitanje može da se postavi

is to look at the Neanderthal that comes from Southern Europe

je da se posmatra Neandertalac koji potiče iz Južne Evrope

and compare it to genomes

i da se uporedi sa genomima

of people who live today.

ljudi koji su danas živi.

So we then look

Pa zatim gledamo

to do this with pairs of individuals,

da to uradimo sa parovima pojedinaca,

starting with two Africans,

počevši od dva Afrikanca,

looking at the two African genomes,

posmatrajući dva afrička genoma,

finding places where they differ from each other,

pronalazeći mesta na kojima se međusobno razlikuju

and in each case ask: What is a Neanderthal like?

i za svaki taj primer postavljamo pitanje: kako izgleda Neandertalac?

Does it match one African or the other African?

Da li se poklapa sa jednim Afrikancem ili sa drugim Afrikancem?

We would expect there to be no difference,

Očekivali bismo da tu ne bude razlike,

because Neanderthals were never in Africa.

jer Neandertalci nikada nisu bili u Africi.

They should be equal, have no reason to be closer

Trebalo bi da su podjednaki, nema razloga da budu bliži

to one African than another African.

jednom Afrikancu nego drugom.

And that's indeed the case.

I to je zaista i slučaj.

Statistically speaking, there is no difference

Posmatrajući statistički, nema razlike

in how often the Neanderthal matches one African or the other.

u tome koliko se često Neandertalac poklapa sa jednim ili drugim Afrikancem.

But this is different

Ali, uočava se razlika

if we now look at the European individual and an African.

ako sada pogledamo pojedinca iz Evrope i jednog Afrikanca.

Then, significantly more often,

Tada, statistički značajno češće

does a Neanderthal match the European

se Neandertalac poklapa sa Evropljaninom

rather than the African.

nego sa Afrikancem.

The same is true if we look at a Chinese individual

Isto to važi i ako posmatramo pojedinca iz Kine

versus an African,

naspram Afrikanca,

the Neanderthal will match the Chinese individual more often.

Neandertalac će se češće poklapati sa kineskom individuom.

This may also be surprising

To takođe može biti iznenađujuće,

because the Neanderthals were never in China.

jer Neandertalci nikada nisu bili u Kini.

So the model we've proposed to explain this

Dakle, model koji predlažemo da bismo to objasnili

is that when modern humans came out of Africa

je da, kada su moderni ljudi izašli iz Afrike

sometime after 100,000 years ago,

negde pre 100.000 godina,

they met Neanderthals.

sreli su se sa Neandertalcima.

Presumably, they did so first in the Middle East,

Verovatno se to prvi put desilo na Bliskom istoku

where there were Neanderthals living.

gde su Neandertalci živeli.

If they then mixed with each other there,

Ako su se tamo međusobno mešali,

then those modern humans

onda bi ti moderni ljudi

that became the ancestors

koji su postali preci

of everyone outside Africa

svima van Afrike

carried with them this Neanderthal component in their genome

preneli tu neandertalsku komponentu u svom genomu

to the rest of the world.

u ostale delove sveta.

So that today, the people living outside Africa

Tako da, danas, ljudi koji žive van Afrike

have about two and a half percent of their DNA

imaju oko dva i po procenta svoje DNK

from Neanderthals.

od Neandertalaca.

So having now a Neanderthal genome

Dakle, sada kad imamo neandertalski genom

on hand as a reference point

pri ruci, kao referentnu tačku

and having the technologies

i kad imamo tehnologije

to look at ancient remains

da ispitujemo drevne ostatke

and extract the DNA,

i da ekstrahujemo DNK,

we can begin to apply them elsewhere in the world.

možemo početi da ih primenjujemo i drugde u svetu.

And the first place we've done that is in Southern Siberia

I prvo mesto na kom smo to uradili je u Južnom Sibiru

in the Altai Mountains

u Altajskim planinama

at a place called Denisova,

u mestu pod imenom Denisova,

a cave site in this mountain here,

u pećinskom nalazištu na toj planini,

where archeologists in 2008

gde su arheolozi 2008. godine

found a tiny little piece of bone --

našli malecko parče kosti --

this is a copy of it --

ovo je kopija toga --

that they realized came from the last phalanx

za koje su shvatili da potiče od zadnje falange

of a little finger of a pinky of a human.

malog prsta čoveka.

And it was well enough preserved

I to parče je bilo dovoljno dobro sačuvano

so we could determine the DNA from this individual,

pa smo mogli da odredimo DNK iz ove jedinke,

even to a greater extent

i to čak u većem stepenu,

than for the Neanderthals actually,

nego za Neandertalce i mogli

and start relating it to the Neanderthal genome

smo da počnemo da to upoređujemo sa neandertalskim

and to people today.

genomom i sa današnjim ljudima.

And we found that this individual

I pronašli smo da ova jedinka

shared a common origin for his DNA sequences

deli zajedničke predačke osnove DNK sekvenci

with Neanderthals around 640,000 years ago.

sa Neandertalcima, od pre oko 640.000 godina.

And further back, 800,000 years ago

A još dalje u prošlost, pre oko 800.000 godina,

is there a common origin

se nalaze zajedničke predačke tačke

with present day humans.

sa današnjim ljudima.

So this individual comes from a population

Dakle, ta jedinka potiče iz populacije

that shares an origin with Neanderthals,

koja deli poreklo sa Neandertalcima,

but far back and then have a long independent history.

ali daleko u prošlosti, a zatim ide kroz dugu nezavisnu istoriju.

We call this group of humans,

Mi imamo naziv za ovu grupu ljudi,

that we then described for the first time

koju smo tada opisali po prvi put

from this tiny, tiny little piece of bone,

iz ovog majušnog parčeta kosti,

the Denisovans,

zovemo ih ljudima iz Denisove,

after this place where they were first described.

po mestu na kojem su prvi put opisani.

So we can then ask for Denisovans

Pa tako možemo pitati za ljude iz Denisove

the same things as for the Neanderthals:

iste stvari kao za Neandertalce:

Did they mix with ancestors of present day people?

Da li su se mešali sa precima današnjih ljudi?

If we ask that question,

Ako postavimo to pitanje,

and compare the Denisovan genome

i ako uporedimo genom ljudi iz Denisove

to people around the world,

sa ljudima širom sveta

we surprisingly find

iznenađujuće otkriće je

no evidence of Denisovan DNA

da nema dokaza o denisovskoj DNK

in any people living even close to Siberia today.

ni kod jednog savremenog naroda, čak ni kod onih blizu Sibira.

But we do find it in Papua New Guinea

Ali, pronašli smo ih u Papui Novoj Gvineji

and in other islands in Melanesia and the Pacific.

i drugim ostrvima u Melaneziji i Pacifiku.

So this presumably means

To, po svoj prilici, znači

that these Denisovans had been more widespread in the past,

da su ljudi iz Denisove bili u prošlosti šire rasprostranjeni,

since we don't think that the ancestors of Melanesians

jer ne smatramo da su preci ljudi iz Melanezije

were ever in Siberia.

ikada bili u Sibiru.

So from studying

Dakle, putem proučavanja

these genomes of extinct humans,

ovih genoma izumrlih ljudi,

we're beginning to arrive at a picture of what the world looked like

počinjemo da dobijamo sliku o tome kako je izgledao svet

when modern humans started coming out of Africa.

kada su moderni ljudi počeli da izlaze iz Afrike.

In the West, there were Neanderthals;

Na zapadu su bili Neandertalci;

in the East, there were Denisovans --

na istoku su bili ljudi iz Denisove -

maybe other forms of humans too

možda i neke druge forme ljudi

that we've not yet described.

koje još nismo opisali.

We don't know quite where the borders between these people were,

Još uvek ne znamo sasvim gde su bile granice između ovih ljudi,

but we know that in Southern Siberia,

ali znamo da su u Južnom Sibiru,

there were both Neanderthals and Denisovans

živeli i Neandertalci i ljudi iz Denisove

at least at some time in the past.

bar neko vreme u prošlosti.

Then modern humans emerged somewhere in Africa,

Zatim su se moderni ljudi pojavili negde u Africi,

came out of Africa, presumably in the Middle East.

izašli su iz Afrike, po svoj prilici na Bliski Istok.

They meet Neanderthals, mix with them,

Sreli su Neandertalce, mešali se sa njima,

continue to spread over the world,

nastavili su da napreduju širom sveta,

and somewhere in Southeast Asia,

i negde u Jugoistočnoj Aziji,

they meet Denisovans and mix with them

sreli su ljude iz Denisove i mešali se sa njima

and continue on out into the Pacific.

i nastavili su dalje ka Pacifiku.

And then these earlier forms of humans disappear,

A onda su ove ranije forme ljudi nestale,

but they live on a little bit today

ali su i danas u maloj meri prisutne

in some of us --

u nekima od nas --

in that people outside of Africa have two and a half percent of their DNA

po tome što ljudi van Afrike imaju dva i po procenta svoje DNK

from Neanderthals,

od Neandertalaca,

and people in Melanesia

a ljudi u Melaneziji

actually have an additional five percent approximately

u stvari imaju dodatnih pet procenata otprilike

from the Denisovans.

od ljudi iz Denisove.

Does this then mean that there is after all

Da li ovo znači da ipak postoji

some absolute difference

neka apsolutna razlika

between people outside Africa and inside Africa

između ljudi van Afrike i unutar Afrike

in that people outside Africa

po tome da ljudi van Afrike

have this old component in their genome

imaju ovu staru komponentu u svom genomu

from these extinct forms of humans,

od ovih izumrlih ljudski formi,

whereas Africans do not?

dok Afrikanci to nemaju?

Well I don't think that is the case.

Pa, ja mislim da to nije slučaj.

Presumably, modern humans

Po svoj prilici, moderni ljudi

emerged somewhere in Africa.

su se pojavili negde u Africi.

They spread across Africa also, of course,

Proširili su se kroz Afriku, naravno,

and there were older, earlier forms of humans there.

a tamo su postojale starije, ranije forme ljudi.

And since we mixed elsewhere,

I budući da smo se mešali na drugim mestima,

I'm pretty sure that one day,

prilično sam siguran da ćemo, jednog dana,

when we will perhaps have a genome

možda kad budemo imali genom

of also these earlier forms in Africa,

i ovih ranijih formi u Africi,

we will find that they have also mixed

pronaći da su se i oni mešali

with early modern humans in Africa.

sa ranim modernim ljudima u Africi.

So to sum up,

Dakle da sumiramo,

what have we learned from studying genomes

šta smo naučili putem proučavanja genoma

of present day humans

današnjih ljudi

and extinct humans?

i izumrlih ljudi?

We learn perhaps many things,

Moguće je da smo saznali mnogo stvari,

but one thing that I find sort of important to mention

ali jedna stvar za koju smatram da je važno pomenuti

is that I think the lesson is that we have always mixed.

po mom mišljenju je ta lekcija da smo se oduvek mešali.

We mixed with these earlier forms of humans,

Mešali smo se sa ovim ranijim formama ljudi,

wherever we met them,

gde god smo ih sreli,

and we mixed with each other ever since.

i mešamo se međusobno od tada do danas.

Thank you for your attention.

Hvala vam na pažnji.

(Applause)

(Aplauz)