What I want to talk to you about is what we can learn from studying the genomes of living people and extinct humans. But before doing that, I just briefly want to remind you about what you already know: that our genomes, our genetic material, are stored in almost all cells in our bodies in chromosomes in the form of DNA, which is this famous double-helical molecule. And the genetic information is contained in the form of a sequence of four bases abbreviated with the letters A, T, C and G. And the information is there twice -- one on each strand -- which is important, because when new cells are formed, these strands come apart, new strands are synthesized with the old ones as templates in an almost perfect process.
Ono o čemu želim da vam govorim je ono što možemo da saznamo proučavajući genome živih ljudi i izumrlih ljudi. Ali, pre nego što to uradim, želim samo kratko da vas podsetim na nešto što već znate: da su naši genomi, naš genetički materijal, uskladišteni u skoro svim ćelijama naših tela u hromozomima u obliku DNK, što je čuveni molekul u obliku dvostruke spirale. I da se genetička informacija nalazi u obliku sekvence od četiri baze koje se skraćeno označavaju slovima A, T, C i G. I ta informacija je tu u duplikatu - po jedna na svakom lancu DNK - što je važno, jer, kada se formiraju nove ćelije, ovi lanci se razdvajaju novi lanci se sintetišu koristeći stare lance kao obrasce tokom jednog skoro savršenog procesa.
But nothing, of course, in nature is totally perfect, so sometimes an error is made and a wrong letter is built in. And we can then see the result of such mutations when we compare DNA sequences among us here in the room, for example. If we compare my genome to the genome of you, approximately every 1,200, 1,300 letters will differ between us. And these mutations accumulate approximately as a function of time. So if we add in a chimpanzee here, we will see more differences. Approximately one letter in a hundred will differ from a chimpanzee.
Ali, naravno, ništa u prirodi nije potpuno savršeno, tako da se ponekad desi greška i ugradi se pogrešno slovo. I možemo videti rezultat takvih mutacija kada uporedimo DNK sekvence na primer između svih nas u ovoj sali. Ako uporedimo moj genom sa vašim genomom, otprilike svakih 1.200, 1.300 slova će se razlikovati među nama. I ove mutacije se nagomilavaju može se reći da postoji vremenska zavisnost. A ako tu ubacimo šimpanzu, videćemo više razlika. Otprilike jedno slovo na svakih sto će se razlikovati od šimpanzinog.
And if you're then interested in the history of a piece of DNA, or the whole genome, you can reconstruct the history of the DNA with those differences you observe. And generally we depict our ideas about this history in the form of trees like this. In this case, it's very simple. The two human DNA sequences go back to a common ancestor quite recently. Farther back is there one shared with chimpanzees. And because these mutations happen approximately as a function of time, you can transform these differences to estimates of time, where the two humans, typically, will share a common ancestor about half a million years ago, and with the chimpanzees, it will be in the order of five million years ago.
I onda, ako vas interesuje istorija komadića DNK ili celog genoma, možete da rekonstruišete istoriju DNK koristeći te razlike koje ste uočili. I obično predstavljamo naše ideje o toj istoriji u obliku ovakvih razgranatih dijagrama. U ovom slučaju je vrlo jednostavno. Ove dve ljudske DNK sekvence idu unazad do zajedničkog pretka u skorijoj prošlosti. Još više unazad je predak kojeg dele sa šimpanzama. I budući da ove mutacije uglavnom imaju vremensku zavisnost, možete transformisati ove razlike u procene vremenskih perioda, pri čemu će dve ljudske vrste, tipično imati zajedničkog pretka od pre oko pola miliona godina, dok će sa šimpanzama, to biti reda veličine od pet miliona godina.
So what has now happened in the last few years is that there are account technologies around that allow you to see many, many pieces of DNA very quickly. So we can now, in a matter of hours, determine a whole human genome. Each of us, of course, contains two human genomes -- one from our mothers and one from our fathers. And they are around three billion such letters long. And we will find that the two genomes in me, or one genome of mine we want to use, will have about three million differences in the order of that. And what you can then also begin to do is to say, "How are these genetic differences distributed across the world?" And if you do that, you find a certain amount of genetic variation in Africa. And if you look outside Africa, you actually find less genetic variation. This is surprising, of course, because in the order of six to eight times fewer people live in Africa than outside Africa. Yet the people inside Africa have more genetic variation.
Dakle, ono što se dešava u poslednjih nekoliko godina je da postoje tehnologije za procenu koje nam omogućavaju da, vrlo brzo vidimo mnogo, mnogo komadića DNK. Pa tako sada možemo da, za nekoliko sati, odredimo ceo ljudski genom. Svako od nas, naravno, sadrži dva humana genoma - jedan od majke i drugi od oca. I njihova dužina je oko tri milijarde ovakvih slova. I otkrićemo da dva genoma u meni ili jedan moj genom koji želimo da koristimo, ima oko tri miliona razlika tog reda veličina. I zatim, ono što takođe može da se radi je da se vidi kako su te genetičke razlike distribuirane širom sveta. I ako to uradite, otkrićete određen broj genetičkih varijacija u Africi. A ako pogledate van Afrike, zapravo ćete naći manje genetičkih varijacija. To je, naravno, iznenađujuće, jer, oko šest do osam puta manje ljudi živi u Africi nego van Afrike. A ipak, ljudi u Africi imaju više genetičkih varijacija.
Moreover, almost all these genetic variants we see outside Africa have closely related DNA sequences that you find inside Africa. But if you look in Africa, there is a component of the genetic variation that has no close relatives outside. So a model to explain this is that a part of the African variation, but not all of it, [has] gone out and colonized the rest of the world. And together with the methods to date these genetic differences, this has led to the insight that modern humans -- humans that are essentially indistinguishable from you and me -- evolved in Africa, quite recently, between 100 and 200,000 years ago. And later, between 100 and 50,000 years ago or so, went out of Africa to colonize the rest of the world.
Štaviše, skoro sve ove genetičke varijante koje nalazimo van Afrike imaju DNK sekvence koje su blisko povezane sa onima koje se nalaze u Africi. Ali, ako posmatrate unutar Afrike, postoji komponenta genetičke varijacije koja nema bliske srodnike van Afrike. Dakle, model koji ovo objašnjava je, da je jedan deo, ali ne i celokupna afrička varijacija, izašao i kolonizovao ostatak sveta. I zajedno sa metodama za datiranje genetičkih razlika, ovo je dovelo do zaključka da su moderni ljudi - ljudi koji se praktično ne mogu razlikovati od vas i mene - evoluirali u Africa u vrlo skoroj prošlosti pre oko 100 i 200.000 godina. I kasnije su, pre oko približno 100 i 50.000 godina izašli iz Afrike da kolonizuju ostatak sveta.
So what I often like to say is that, from a genomic perspective, we are all Africans. We either live inside Africa today, or in quite recent exile. Another consequence of this recent origin of modern humans is that genetic variants are generally distributed widely in the world, in many places, and they tend to vary as gradients, from a bird's-eye perspective at least. And since there are many genetic variants, and they have different such gradients, this means that if we determine a DNA sequence -- a genome from one individual -- we can quite accurately estimate where that person comes from, provided that its parents or grandparents haven't moved around too much.
Dakle, ono što ja često volim da kažem je da smo, iz genomske perspektive, mi svi Afrikanci. Sada, ili živimo u Africi, ili smo u egzilu koji je nedavno počeo. Još jedna posledica ovog ne tako davnog porekla modernih ljudi je da su genetičke varijante obično široko rasprostranjene širom sveta, na mnogo mesta, i imaju tendenciju da variraju u vidu gradijenata, bar kad se posmatra iz ptičje perspektive. I budući da postoji mnogo genetičkih varijanti, i da se njihovi gradijenti razlikuju, sledi zaključak da, ako odredimo DNK sekvencu - genom jednog pojedinca - možemo vrlo pouzdano da procenimo odakle je ta osoba, uz uslov da se roditelji te osobe, kao i njihovi roditelji nisu suviše često selili.
But does this then mean, as many people tend to think, that there are huge genetic differences between groups of people -- on different continents, for example? Well we can begin to ask those questions also. There is, for example, a project that's underway to sequence a thousand individuals -- their genomes -- from different parts of the world. They've sequenced 185 Africans from two populations in Africa. [They've] sequenced approximately equally [as] many people in Europe and in China. And we can begin to say how much variance do we find, how many letters that vary in at least one of those individual sequences. And it's a lot: 38 million variable positions.
Ali, da li ovo sada znači, kao što mnogo ljudi ima tendenciju da smatra, da postoje ogromne genetičke razlike između grupa ljudi - na primer, na različitim kontinentima? Pa, možemo početi da postavljamo i takva pitanja. Postoji, na primer, projekat koji je na putu da sekvencionira hiljadu pojedinaca - njihove genome - iz različitih delova sveta. Do sada su sekvencionirali 185 Afrikanaca iz dve populacije u Africi. Sekvencionirali su približno isto toliko ljudi u Evropi i u Kini. I možemo početi da govorimo koliko variranja je nađeno, koliko slova varira u bar jednoj od tih pojedinačnih sekvenci. I to je mnogo: 38 miliona varijabilnih pozicija.
But we can then ask: Are there any absolute differences between Africans and non-Africans? Perhaps the biggest difference most of us would imagine existed. And with absolute difference -- and I mean a difference where people inside Africa at a certain position, where all individuals -- 100 percent -- have one letter, and everybody outside Africa has another letter. And the answer to that, among those millions of differences, is that there is not a single such position. This may be surprising. Maybe a single individual is misclassified or so. So we can relax the criterion a bit and say: How many positions do we find where 95 percent of people in Africa have one variant, 95 percent another variant, and the number of that is 12.
Ali, možemo pitati: da li postoje neke apsolutne razlike između Afrikanaca i ne-Afrikanaca? Možda i najveća razlika koju većina nas može da zamisli zaista postoji. I kad kažem "apsolutna razlika" - pod tim mislim razlika pri kojoj ljudi u Africi, na određenoj poziciji, pri kojoj svi pojedinci - 100 procenata - imaju jedno slovo, a svi drugi van Afrike imaju neko drugo slovo. I odgovor na to je da, od svih tih miliona razlika, nema nijedne takve pozicije. To može biti iznenađujuće. Možda je jedan pojedinac pogrešno klasifikovan ili tako nešto. Pa možemo da malo spustimo kriterijum i da kažemo: Koliko pozicija možemo naći gde 95 procenata ljudi u Africi ima jednu varijantu, a 95 procenata drugu varijantu, i taj broj iznosi 12.
So this is very surprising. It means that when we look at people and see a person from Africa and a person from Europe or Asia, we cannot, for a single position in the genome with 100 percent accuracy, predict what the person would carry. And only for 12 positions can we hope to be 95 percent right. This may be surprising, because we can, of course, look at these people and quite easily say where they or their ancestors came from. So what this means now is that those traits we then look at and so readily see -- facial features, skin color, hair structure -- are not determined by single genes with big effects, but are determined by many different genetic variants that seem to vary in frequency between different parts of the world.
I to je veoma iznenađujuće. To znači da, kada ispitujemo ljude i uočimo osobu iz Afrike i osobu iz Evrope ili Azije, ne možemo, ni za jednu poziciju u genomu sa 100-procentnom sigurnošću, predvideti šta će ta osoba nositi. I samo za 12 pozicija se možemo nadati da budemo 95 procenata u pravu. To može biti iznenađujuće, jer možemo, naravno, pogledati te ljude i sasvim lako reći odakle potiču oni ili njihovi preci. To, dakle, znači da te osobine koje tada posmatramo i tako lako uočavamo - crte lica, boja kože, struktura kose - nisu određene pojedinačnim genima sa velikim efektima, već ih određuje mnogo različitih genetičkih varijanti koje izgleda imaju različitu zastupljenost u različitim delovima sveta.
There is another thing with those traits that we so easily observe in each other that I think is worthwhile to consider, and that is that, in a very literal sense, they're really on the surface of our bodies. They are what we just said -- facial features, hair structure, skin color. There are also a number of features that vary between continents like that that have to do with how we metabolize food that we ingest, or that have to do with how our immune systems deal with microbes that try to invade our bodies. But so those are all parts of our bodies where we very directly interact with our environment, in a direct confrontation, if you like. It's easy to imagine how particularly those parts of our bodies were quickly influenced by selection from the environment and shifted frequencies of genes that are involved in them. But if we look on other parts of our bodies where we don't directly interact with the environment -- our kidneys, our livers, our hearts -- there is no way to say, by just looking at these organs, where in the world they would come from.
Postoji još jedna stvar sa tim osobinama koje tako lako primećujemo jedni na drugima koju smatram da je korisno da razmotrimo, i to je da su, u vrlo bukvalnom smislu, te osobine, u stvari, samo na površini tela. Te osobine su ono što smo upravo rekli - crte lica, struktura kose, boja kože, Postoji takođe i određen broj osobina koje variraju između kontinenata i imaju veze sa tim kako metabolišemo hranu koju unosimo, ili sa tim kako se naš imuni sistem nosi sa mikrobima koji pokušavaju da osvoje naša tela. Ali, to su sve delovi tela preko kojih mi vrlo direktno interagujemo sa okruženjem, u direktnom sučeljavanju, može se reći. Lako je zamisliti da su posebno ti delovi naših tela bili brzo uobličavani putem selekcije iz okruženja i da je to pomerilo učestalost gena koji su povezani sa njima. Ali, ako pogledamo druge delove tela koji nisu u direktnom kontaktu sa okruženjem - naši bubrezi, jetra, naše srce - ne postoji način da se kaže, samo gledanjem na ove organe, iz kog dela sveta potiču.
So there's another interesting thing that comes from this realization that humans have a recent common origin in Africa, and that is that when those humans emerged around 100,000 years ago or so, they were not alone on the planet. There were other forms of humans around, most famously perhaps, Neanderthals -- these robust forms of humans, compared to the left here with a modern human skeleton on the right -- that existed in Western Asia and Europe since several hundreds of thousands of years. So an interesting question is, what happened when we met? What happened to the Neanderthals?
Dakle, postoji druga interesantna stvar koja sledi iz ovog shvatanja da ljudi imaju nedavno zajedničko poreklo u Africi, a to je da, kada su se ti ljudi pojavili pre oko 100.000 godina, nisu bili sami na planeti. Postojale su druge forme ljudi najčuveniji su, verovatno, Neandertalci -- te robusne forme ljudi, ovde sa leve strane, u poređenju sa modernim ljudskim skeletom sa desne strane - koja je postojala u zapadnoj Aziji i Evropi od pre nekoliko stotina hiljada godina. Dakle, zanimljivo pitanje je, šta se desilo kada smo se sreli? Šta se desilo sa Neandertalcima?
And to begin to answer such questions, my research group -- since over 25 years now -- works on methods to extract DNA from remains of Neanderthals and extinct animals that are tens of thousands of years old. So this involves a lot of technical issues in how you extract the DNA, how you convert it to a form you can sequence. You have to work very carefully to avoid contamination of experiments with DNA from yourself. And this then, in conjunction with these methods that allow very many DNA molecules to be sequenced very rapidly, allowed us last year to present the first version of the Neanderthal genome, so that any one of you can now look on the Internet, on the Neanderthal genome, or at least on the 55 percent of it that we've been able to reconstruct so far. And you can begin to compare it to the genomes of people who live today.
I da bismo počeli da odgovaramo na takva pitanja, moja istraživačka grupa - već više od 25 godina - radi na metodama ekstrakcije DNK iz ostataka Neandertalaca i izumrlih životinja starih desetine hiljada godina. To uključuje veliki broj tehničkih detalja o tome kako se izoluje DNK, kako se konvertuje u oblik koji može da se sekvencionira. Morate raditi vrlo pažljivo da biste izbegli kontaminaciju eksperimenta svojom sopstvenom DNK. I zahvaljujući ovome, zajedno sa onim metodama koje omogućavaju da veoma mnogo DNK molekula može vrlo brzo da se sekvencionira, smo prošle godine uspeli da pokažemo prvu verziju neandertalskog genoma, pa tako bilo ko od vas može da pogleda na Internetu i nađe neandertalski genom, ili bar 55 procenata tog genoma što smo do sada uspeli da rekonstruišemo. I može početi da ga upoređuje sa genomima
And one question that you may then want to ask is, what happened when we met? Did we mix or not? And the way to ask that question is to look at the Neanderthal that comes from Southern Europe and compare it to genomes of people who live today. So we then look to do this with pairs of individuals, starting with two Africans, looking at the two African genomes, finding places where they differ from each other, and in each case ask: What is a Neanderthal like? Does it match one African or the other African? We would expect there to be no difference, because Neanderthals were never in Africa. They should be equal, have no reason to be closer to one African than another African. And that's indeed the case. Statistically speaking, there is no difference in how often the Neanderthal matches one African or the other. But this is different if we now look at the European individual and an African. Then, significantly more often, does a Neanderthal match the European rather than the African. The same is true if we look at a Chinese individual versus an African, the Neanderthal will match the Chinese individual more often. This may also be surprising because the Neanderthals were never in China.
ljudi koji žive danas. I jedno pitanje koje ćete možda želeti da postavite je, šta se desilo kada smo se sreli? Jesmo li se mešali ili nismo? I način na koji to pitanje može da se postavi je da se posmatra Neandertalac koji potiče iz Južne Evrope i da se uporedi sa genomima ljudi koji su danas živi. Pa zatim gledamo da to uradimo sa parovima pojedinaca, počevši od dva Afrikanca, posmatrajući dva afrička genoma, pronalazeći mesta na kojima se međusobno razlikuju i za svaki taj primer postavljamo pitanje: kako izgleda Neandertalac? Da li se poklapa sa jednim Afrikancem ili sa drugim Afrikancem? Očekivali bismo da tu ne bude razlike, jer Neandertalci nikada nisu bili u Africi. Trebalo bi da su podjednaki, nema razloga da budu bliži jednom Afrikancu nego drugom. I to je zaista i slučaj. Posmatrajući statistički, nema razlike u tome koliko se često Neandertalac poklapa sa jednim ili drugim Afrikancem. Ali, uočava se razlika ako sada pogledamo pojedinca iz Evrope i jednog Afrikanca. Tada, statistički značajno češće se Neandertalac poklapa sa Evropljaninom nego sa Afrikancem. Isto to važi i ako posmatramo pojedinca iz Kine naspram Afrikanca, Neandertalac će se češće poklapati sa kineskom individuom. To takođe može biti iznenađujuće,
So the model we've proposed to explain this is that when modern humans came out of Africa sometime after 100,000 years ago, they met Neanderthals. Presumably, they did so first in the Middle East, where there were Neanderthals living. If they then mixed with each other there, then those modern humans that became the ancestors of everyone outside Africa carried with them this Neanderthal component in their genome to the rest of the world. So that today, the people living outside Africa have about two and a half percent of their DNA from Neanderthals.
jer Neandertalci nikada nisu bili u Kini. Dakle, model koji predlažemo da bismo to objasnili je da, kada su moderni ljudi izašli iz Afrike negde pre 100.000 godina, sreli su se sa Neandertalcima. Verovatno se to prvi put desilo na Bliskom istoku gde su Neandertalci živeli. Ako su se tamo međusobno mešali, onda bi ti moderni ljudi koji su postali preci svima van Afrike preneli tu neandertalsku komponentu u svom genomu u ostale delove sveta. Tako da, danas, ljudi koji žive van Afrike imaju oko dva i po procenta svoje DNK
So having now a Neanderthal genome on hand as a reference point and having the technologies to look at ancient remains and extract the DNA, we can begin to apply them elsewhere in the world. And the first place we've done that is in Southern Siberia in the Altai Mountains at a place called Denisova, a cave site in this mountain here, where archeologists in 2008 found a tiny little piece of bone -- this is a copy of it -- that they realized came from the last phalanx of a little finger of a pinky of a human. And it was well enough preserved so we could determine the DNA from this individual, even to a greater extent than for the Neanderthals actually, and start relating it to the Neanderthal genome and to people today. And we found that this individual shared a common origin for his DNA sequences with Neanderthals around 640,000 years ago. And further back, 800,000 years ago is there a common origin with present day humans.
od Neandertalaca. Dakle, sada kad imamo neandertalski genom pri ruci, kao referentnu tačku i kad imamo tehnologije da ispitujemo drevne ostatke i da ekstrahujemo DNK, možemo početi da ih primenjujemo i drugde u svetu. I prvo mesto na kom smo to uradili je u Južnom Sibiru u Altajskim planinama u mestu pod imenom Denisova, u pećinskom nalazištu na toj planini, gde su arheolozi 2008. godine našli malecko parče kosti -- ovo je kopija toga -- za koje su shvatili da potiče od zadnje falange malog prsta čoveka. I to parče je bilo dovoljno dobro sačuvano pa smo mogli da odredimo DNK iz ove jedinke, i to čak u većem stepenu, nego za Neandertalce i mogli smo da počnemo da to upoređujemo sa neandertalskim genomom i sa današnjim ljudima. I pronašli smo da ova jedinka deli zajedničke predačke osnove DNK sekvenci sa Neandertalcima, od pre oko 640.000 godina. A još dalje u prošlost, pre oko 800.000 godina, se nalaze zajedničke predačke tačke
So this individual comes from a population that shares an origin with Neanderthals, but far back and then have a long independent history. We call this group of humans, that we then described for the first time from this tiny, tiny little piece of bone, the Denisovans, after this place where they were first described. So we can then ask for Denisovans the same things as for the Neanderthals: Did they mix with ancestors of present day people? If we ask that question, and compare the Denisovan genome to people around the world, we surprisingly find no evidence of Denisovan DNA in any people living even close to Siberia today. But we do find it in Papua New Guinea and in other islands in Melanesia and the Pacific. So this presumably means that these Denisovans had been more widespread in the past, since we don't think that the ancestors of Melanesians were ever in Siberia.
sa današnjim ljudima. Dakle, ta jedinka potiče iz populacije koja deli poreklo sa Neandertalcima, ali daleko u prošlosti, a zatim ide kroz dugu nezavisnu istoriju. Mi imamo naziv za ovu grupu ljudi, koju smo tada opisali po prvi put iz ovog majušnog parčeta kosti, zovemo ih ljudima iz Denisove, po mestu na kojem su prvi put opisani. Pa tako možemo pitati za ljude iz Denisove iste stvari kao za Neandertalce: Da li su se mešali sa precima današnjih ljudi? Ako postavimo to pitanje, i ako uporedimo genom ljudi iz Denisove sa ljudima širom sveta iznenađujuće otkriće je da nema dokaza o denisovskoj DNK ni kod jednog savremenog naroda, čak ni kod onih blizu Sibira. Ali, pronašli smo ih u Papui Novoj Gvineji i drugim ostrvima u Melaneziji i Pacifiku. To, po svoj prilici, znači da su ljudi iz Denisove bili u prošlosti šire rasprostranjeni, jer ne smatramo da su preci ljudi iz Melanezije
So from studying these genomes of extinct humans, we're beginning to arrive at a picture of what the world looked like when modern humans started coming out of Africa. In the West, there were Neanderthals; in the East, there were Denisovans -- maybe other forms of humans too that we've not yet described. We don't know quite where the borders between these people were, but we know that in Southern Siberia, there were both Neanderthals and Denisovans at least at some time in the past. Then modern humans emerged somewhere in Africa, came out of Africa, presumably in the Middle East. They meet Neanderthals, mix with them, continue to spread over the world, and somewhere in Southeast Asia, they meet Denisovans and mix with them and continue on out into the Pacific. And then these earlier forms of humans disappear, but they live on a little bit today in some of us -- in that people outside of Africa have two and a half percent of their DNA from Neanderthals, and people in Melanesia actually have an additional five percent approximately from the Denisovans.
ikada bili u Sibiru. Dakle, putem proučavanja ovih genoma izumrlih ljudi, počinjemo da dobijamo sliku o tome kako je izgledao svet kada su moderni ljudi počeli da izlaze iz Afrike. Na zapadu su bili Neandertalci; na istoku su bili ljudi iz Denisove - možda i neke druge forme ljudi koje još nismo opisali. Još uvek ne znamo sasvim gde su bile granice između ovih ljudi, ali znamo da su u Južnom Sibiru, živeli i Neandertalci i ljudi iz Denisove bar neko vreme u prošlosti. Zatim su se moderni ljudi pojavili negde u Africi, izašli su iz Afrike, po svoj prilici na Bliski Istok. Sreli su Neandertalce, mešali se sa njima, nastavili su da napreduju širom sveta, i negde u Jugoistočnoj Aziji, sreli su ljude iz Denisove i mešali se sa njima i nastavili su dalje ka Pacifiku. A onda su ove ranije forme ljudi nestale, ali su i danas u maloj meri prisutne u nekima od nas -- po tome što ljudi van Afrike imaju dva i po procenta svoje DNK od Neandertalaca, a ljudi u Melaneziji u stvari imaju dodatnih pet procenata otprilike
Does this then mean that there is after all some absolute difference between people outside Africa and inside Africa in that people outside Africa have this old component in their genome from these extinct forms of humans, whereas Africans do not? Well I don't think that is the case. Presumably, modern humans emerged somewhere in Africa. They spread across Africa also, of course, and there were older, earlier forms of humans there. And since we mixed elsewhere, I'm pretty sure that one day, when we will perhaps have a genome of also these earlier forms in Africa, we will find that they have also mixed with early modern humans in Africa.
od ljudi iz Denisove. Da li ovo znači da ipak postoji neka apsolutna razlika između ljudi van Afrike i unutar Afrike po tome da ljudi van Afrike imaju ovu staru komponentu u svom genomu od ovih izumrlih ljudski formi, dok Afrikanci to nemaju? Pa, ja mislim da to nije slučaj. Po svoj prilici, moderni ljudi su se pojavili negde u Africi. Proširili su se kroz Afriku, naravno, a tamo su postojale starije, ranije forme ljudi. I budući da smo se mešali na drugim mestima, prilično sam siguran da ćemo, jednog dana, možda kad budemo imali genom i ovih ranijih formi u Africi, pronaći da su se i oni mešali sa ranim modernim ljudima u Africi.
So to sum up, what have we learned from studying genomes of present day humans and extinct humans? We learn perhaps many things, but one thing that I find sort of important to mention is that I think the lesson is that we have always mixed. We mixed with these earlier forms of humans, wherever we met them, and we mixed with each other ever since.
Dakle da sumiramo, šta smo naučili putem proučavanja genoma današnjih ljudi i izumrlih ljudi? Moguće je da smo saznali mnogo stvari, ali jedna stvar za koju smatram da je važno pomenuti po mom mišljenju je ta lekcija da smo se oduvek mešali. Mešali smo se sa ovim ranijim formama ljudi, gde god smo ih sreli, i mešamo se međusobno od tada do danas.
Thank you for your attention.
Hvala vam na pažnji.
(Applause)
(Aplauz)