How a new species of ancestors is changing our theory of human evolution | Juliet Brophy

Translator: Leslie Gauthier Reviewer: Krystian Aparta

Prevodilac: Aleksandar Bošnjak Lektor: Ivana Krivokuća

Human origins.

Ljudsko poreklo.

Who are we?

Ko smo mi?

Where do we come from,

Odakle potičemo

and how do we know?

i kako da znamo?

In my field, paleoanthropology,

U mojoj struci, paleoantropologiji,

we explore human origins --

istražujemo ljudsko poreklo -

the "who" and "where" questions --

pitanja „ko“ i „gde“ -

by analyzing fossils that date back thousands and even millions of years.

analizirajući fosile koji su stari hiljade, čak i milione godina.

In 2015, a team of colleagues and I named a new species in the genus Homo --

Godine 2015, tim kolega i ja imenovali smo novu vrstu roda Homo -

our genus --

našeg roda -

Homo naledi.

Homo naledi.

Let's take a step back and put that into context.

Hajde da se vratimo korak unazad i da stavimo to u kontekst.

The last common ancestors between humans and chimps

Poslednji zajednički predak između ljudi i šimpanza

date somewhere between six and eight million years.

je star negde između šest i osam miliona godina.

The earliest hominins,

Najraniji hominini,

or earliest human ancestors,

ili najraniji ljudski preci,

evolved into a group known as the australopithecines.

su se razvili u grupu poznatu kao austalopitekusi.

The australopithecines evolved into the genus Homo

Australopitekusi su se razvili u rod Homo

and eventually modern humans -- us.

i na kraju u moderne ljude - nas.

With each new fossil discovery,

Sa svakim novim otkrićem fosila,

we get a little bit closer to better understanding who we are

približavamo se boljem razumevanju

toga ko smo i odakle potičemo.

and where we came from.

With these new fossil finds,

Sa tim novim otkrićima fosila,

we realize we now have to make changes to this tree.

sad shvatamo da moramo da unesemo izmene u genetsko stablo.

Until this discovery,

Sve do ovog otkrića,

we thought we had a pretty good idea about the patterns of evolutionary change.

mislili smo da imamo prilično dobru ideju o obrascima evolutivnih promena.

Current fossil evidence suggests

Trenutni fosilni ostaci ukazuju

that the earliest populations of the genus Homo evolved in Africa

da su se najranije populacije roda Homo razvile u Africi,

somewhere between two and three million years.

pre oko dve i tri miliona godina.

Fast-forward to approximately 300,000 years to where we see the origins

Premotajmo vreme do pre približno 300 000 godina,

kad vidimo početke prvih modernih ljudi.

of the first modern humans.

While the fossil record between these time frames in Africa

Iako su zapisi fosila između ovih vremenskih okvira u Africi

is relatively sparse,

relativno retki,

the fossils nonetheless demonstrated certain trends

fosili su i pored toga pokazali određene karakteristike

from our earliest ancestors to modern humans.

od naših najranijih predaka sve do modernih ljudi.

For example, our brains were becoming larger

Na primer, naši mozgovi su postajali veći

relative the rest of our body.

u odnosu na ostatak tela.

Our pelves were becoming more bowl-shaped,

Naše karlice su postajale više okruglaste,

and our hand-wrist morphology, or form,

a morfologija, ili oblik, naših ručnih zglobova,

suggested a change in our grip as we began to make and use stone tools

je ukazivala na promenu u stisku čim smo počeli da pravimo

i koristimo kameno oruđe, a manje provodimo vreme na drveću.

and spend less time in the trees.

These new fossils disrupt everything we thought we knew about these trends

Ovi novi fosili su poremetili sve što smo mislili da znamo o ovim karakteristikama

and force us to change the way that we think about human evolution.

i naterali nas da promenimo način na koji razmišljamo o evoluciji čoveka.

South Africa in general,

Južna Afrika uopšteno,

but the Cradle of Humankind in particular,

ali Kolevka čovečanstva naročito,

contains numerous sites where hundreds of thousands of fossils have been found.

sadrži brojna nalazišta

na kojima je nađeno stotine hiljada fosila.

As an undergraduate student, I fell in love with one of them ...

Kao student, zaljubila sam se u jednog od njih...

Mrs. Ples.

Gospođu Ples.

The skull of a 2.1-million-year-old early human ancestor.

Lobanju ranog ljudskog pretka staru 2,1 miliona godina.

From that point on,

Od tog trenutka,

I was determined to go to South Africa and study human evolution.

bila sam odlučna da odem u Južnu Afriku i da izučavam ljudsku evoluciju.

I first traveled there in 2003,

Prvi put sam otišla tamo 2003. godine,

and I did get to see my beloved Mrs. Ples.

i dobila sam priliku da vidim moju voljenu Gospođu Ples.

(Laughter)

(Smeh)

But words can hardly convey my excitement

Reči teško mogu da prenesu moje uzbuđenje

when I was chosen as an early career scientist

kada me je kao mladog naučnika odabrao

by Lee Berger,

Li Berger,

a world-renowned paleoanthropologist,

svetski poznat paleoantropolog,

to be one of the primary analysts of recently excavated unpublished fossils.

da budem jedan od glavnih analitičara nedavno otkopanih neobjavljenih fosila.

This treasure trove of fossils was being recovered from a new site

Veliko otkriće fosila je otkriveno na novom nalazištu

called the Dinaledi Chamber in the Rising Star cave system.

zvano Odaja Dinaledi u sistemu pećina „Zvezda u usponu".

Species are often named based on a skull, a lower jaw,

Vrste često dobijaju nazive na osnovu lobanja, donje vilice,

or, very rarely,

ili, veoma retko, na osnovu

a handful of postcranial, or below-the-neck, elements.

nekoliko postkranijalnih elemenata, odnosno delova koji se nalaze ispod vrata.

The fossils from Dinaledi were another story altogether.

Fosili iz Dinaledija su priča za sebe.

An unprecedented approximately 1800 specimens --

Jedinstvenih približno 1 800 uzoraka -

so far --

do sada -

have been excavated from the Rising Star system,

je bilo iskopano iz sistema „Zvezde u usponu",

representing at least 15 individual skeletons.

a koji su predstavljali barem 15 zasebnih skeleta.

The research team that I was invited to join

Istraživački tim u koji sam pozvana

was tasked with describing, comparing and analyzing the fossils,

je dobio zadatak da opisuje, upoređuje i analizira fosile,

with the difficult goal of identifying to what species the fossils belonged.

sa teškim ciljem da identifikuje kojoj vrsti su fosili pripadali.

We were divided up into our different areas of expertise.

Bili smo podeljeni na različita stručna polja.

We were divided up in different areas of the lab, too.

Takođe, bili smo podeljeni u različite delove laboratorije.

So there was "Hand Land," for the fossil hand people,

Dakle, postojala je „Zemlja ruku”, za ljude koji istražuju ruke fosila,

"Hip Heaven" for the pelvis ...

„Raj kukova” za karlicu...

I was in the "Tooth Booth."

Ja sam bila u „Štandu zuba".

(Laughter)

(Smeh)

And after long, intense days in the lab,

Nakon dugih, intenzivnih dana u laboratoriji,

the different teams would meet up at night and discuss our findings,

različiti timovi bi se sastajali noću i diskutovali o zaključcima,

still consumed by questions from our analyses.

i dalje obuzeti pitanjima iz naših analiza.

It was incredible how different the interpretations were.

Bilo je neverovatno koliko su tumačenja bila različita.

Each body part seemed to come from a different species,

Izgledalo je kao da svaki deo tela pripada drugačijoj vrsti,

based on what we knew from the fossil record.

na osnovu onoga što znamo iz zapisa o fosilima.

The suite of characteristics we were seeing didn't match any known species.

Nizovi karakteristika nisu se slagali ni sa jednom poznatom vrstom.

And if we had only recovered the skull, we might have called it one thing;

Da smo otkrili samo lobanju, možda bismo je zvali na jedan način;

if we had only recovered the pelvis, we might have called it another.

da smo otkrili samo karlicu, možda bismo je nazvali drugačije.

The anatomy of the skeletons didn't make sense

Anatomija skeleta nije imala smisla u odnosu

with the framework of what we thought we knew of human evolution.

na vremenski okvir za koji smo mislili da znamo o evoluciji čoveka.

Did it belong in the genus Homo?

Je li je pripadao rodu Homo?

Should it be an australopithecine?

Da li bi trebalo da bude australopitekus?

Those bipedal, more apelike ancestors?

Kao oni dvonožni preci nalik majmunima?

Or perhaps it should be its own species.

Ili bi možda trebalo da bude posebna vrsta.

Ultimately, after much deliberation,

Na kraju, nakon mnogo promišljanja,

we decided the Rising Star specimens did indeed warrant a new species,

odlučili smo da uzorci iz „Zvezde u usponu” garantuju novu vrstu,

which we called "Homo naledi."

koju smo nazvali Homo naledi.

From the head to the feet,

Od glave do pete,

the fossils present a mosaic of primitive, or ancestral,

fosili predstavljaju mozaik primitivnih, ili nasleđenih,

and derived or more modern-like features.

i izvedenih karakteristika koje su nalik modernim.

The skull is quite derived,

Lobanja je poprilično izvedena,

appearing most similar to early representatives of the genus Homo,

najsličnija ranom predstavniku roda Homo,

like Homo habilis and Homo erectus.

kao npr. Homo habilisu i Homo erektusu.

However, the brain is scarcely half the size of a modern human one.

Međutim, mozak je jedva jednak polovini mozga modernog čoveka.

One that is smaller than any other early Homo that has ever been found.

Manji je od mozga bilo kojeg ranog pripadnika roda Homo koji je ikada nađen.

As someone who studies teeth,

Kao neko ko proučava zube,

I might argue these are the coolest fossils found at the site.

mogla bih da tvrdim da su ovo najbolji fosili koji su nađeni.

(Laughter)

(Smeh)

The assemblage consists of 190 whole or fragmentary teeth

Montaža se sastoji od 190 celih ili okrnjenih zuba

that range in age from very old to very young.

koji variraju u starosti od veoma starog do veoma mladog.

Like the skeletons,

Kao i skeleti,

the teeth present a mix of primitive and derived traits.

zubi predstavljaju mešavinu primitivnih i izvedenih osobina.

In modern humans,

Kod modernih ljudi,

the third molar is typically the smallest, while the first molar is the biggest,

umnjak je tipično najmanji, dok je prvi kutnjak najveći,

but Homo naledi has the primitive condition

ali Homo naledi je u primitivnom stanju

where the third molar is the biggest and the first molar is the smallest.

gde je umnjak najveći, a prvi kutnjak najmanji.

The anterior teeth,

Prednji zubi,

or the incisors and canines,

sekutići i očnjaci,

are small for the genus Homo,

su mali za rod Homo,

and the lower canine has a cuspulid on it --

a donji očnjaci imaju na sebi šiljak -

an extra cuspule that gives it a distinct mitten-like shape

dodatan vrh koji im daje karakterističan oblik rukavice

that it shares with some specimens of the early human, Homo erectus.

koji deli sa nekim uzorcima ranih ljudi, Homo erektusom.

The overall shape of the teeth looked odd to me,

Uopšteno, oblici zuba su mi izgledali čudno,

so I performed crown-shape analysis

tako da sam odradila analizu krunice

on the occlusal surfaces of deciduous teeth, or baby teeth --

na okluzalnim površinama mlečnih zuba, ili bebećih zuba -

on your left --

na vašoj levoj strani -

and the permanent premolars and molars on your right.

i trajnih pretkutnjaka i kutnjaka na vašoj desnoj strani.

The deciduous teeth are especially narrow,

Mlečni zubi su naročito uski,

and the premolars are unique in their outline shape

a pretkutnjaci su jedinstveni po svojoj konturi

compared to other hominids.

u poređenju sa drugim hominidima.

In fact, when I compare the outlines,

Zapravo, kad upoređujem konture,

when I lay them on top of each other,

kad stavim jedan na drugi,

they look very similar.

izgledaju veoma slično.

We say they have "low intraspecific variations,"

Kažemo da imaju „niske intraspecifične varijacije”,

so the variation within the species is low.

varijacija u samoj vrsti je mala.

When I compare this to groups like the australopithecines,

Kad uporedim ovo sa grupom poput australopitekusa,

the intraspecific variation is much larger.

intraspecifična varijacija je mnogo veća.

Postcranially, the team concluded

Postkranijalno, tim je zaključio

that the position of the shoulders suggesting naledi was a climber;

da položaj ramena ukazuje da je naledi bio penjač;

the flared pelvis and curved fingers are all primitive for the genus Homo.

raširena karlica i zakrivljeni prsti su primitivne karakteristike za rod Homo.

On the other hand,

Sa druge strane,

the humanlike wrist, long slender legs and modern feet

zglob poput čovekovog, duge vitke noge i moderna stopala

are all consistent with other members of the genus.

su dosledni drugim članovima roda.

In 2017, we announced more specimens of Homo naledi

Godine 2017, najavili smo više uzoraka Homo naledija

from the nearby Lesedi Chamber,

iz obližnje Odaje Lasedi,

also in the Rising Star cave system.

takođe u sistemu pećina „Zvezda u usponu”.

In addition, our geology team managed to produce an age estimate.

Dodatno, naš tim geologa je uspeo da proceni godine.

The date's a big deal because, up until now,

Datum je velika stvar jer, sve do sada,

we had based our analysis solely on the morphology of the specimens,

zasnivali smo naše analize jedino na morfologiji uzoraka,

without previous knowledge of how old something is --

bez pređašnjeg znanja koliko je nešto staro -

something which could unconsciously bias our interpretations.

što bi moglo nesvesno loše da utiče na naša tumačenja.

With its small brain and flared pelvis,

Sa njihovim malim mozgovima i raširenim karlicama,

we would not have been surprised

ne bismo bili iznenađeni

if the fossils turned out to be two million years old.

ako ispadne da su fosili stari dva miliona godina.

Instead, the fossils dated

Umesto toga, fosili su bili stari

to 235 to 336 thousand years,

235 do 336 hiljada godina,

an incredibly young date for such a small-brained individual.

što je neverovatno rano za osobu sa malim mozgom.

So think back to what I said earlier:

Mislite o onom što sam rekla ranije:

we thought that our brains were becoming larger relative to the rest of our body.

mislili smo da su mozgovi postajali veći u odnosu na ostatak tela.

Now we have a small-brained, young individual complicating this idea.

Sada imamo mladog pojedinca sa malim mozgom koji komplikuje ovu ideju.

What does all this mean?

Šta sve ovo znači?

Homo naledi has taught us

Homo naledi nas je naučio

that we need to reassess what it means to be in the genus Homo.

da moramo preispitati šta znači biti u rodu Homo.

We need to rethink what it means to be human.

Moramo ponovo da razmišljamo o tome šta znači biti čovek.

In fact, most of the characteristics that we use to define the genus Homo,

U stvari, većinu karakteristika koje koristimo da definišemo rod Homo,

such as brain size and hip morphology,

poput veličine mozga i morfologije kuka,

are no longer valid.

nisu više validni.

No other species exists with this mix of primitive and derived traits.

Ne postoji nijedna druga vrsta

sa ovakvom mešavinom primitivnih i izvedenih osobina.

Why is there so much morphological variation in the genus Homo?

Zašto u rodu Homo postoji toliko morfoloških varijacija?

And what force is driving that variation?

I koja sila pobuđuje tu varijaciju?

Another implication for these fossils is that for the first time,

Druga naznaka ovih fosila je da po prvi put

we have concrete evidence of a species coexisting in Africa,

imamo konkretne dokaze o koegzistenciji vrsta u Africi,

at 300,000 years,

pre 300 000 godina,

with modern humans.

sa modernim čovekom.

Until this discovery,

Sve do ovog otkrića,

we only had large-brained modern humans that existed in Africa.

znali smo samo za moderne ljude sa velikim mozgovima u Africi.

Did they interbreed with each other?

Da li su se mešali međusobno?

Did they compete with each other?

Da li su se takmičili međusobno?

Another implication that these fossils have

Druga naznaka koju ovi fosili imaju

is for the archaeologists studying stone tools in South Africa.

je za arheologe koji proučavaju kameno oruđe u Južnoj Africi.

Keep in mind that neither the Dinaledi nor the Lesedi Chambers

Imajte na umu da ni Dinaledi niti Odaja Lesedi

have any artifacts in them.

nemaju nikakve predmete u njima.

However, they do overlap in time with several stone-tool industries,

Međutim, oni se preklapaju sa vremenom nekoliko industrija kamenog oruđa,

the makers of which are considered to be either modern humans

čiji su tvorci smatrani modernim čovekom

or direct human ancestors.

ili direktnim čovekovim pretkom.

This begs the question:

To podstiče pitanje:

Who made the stone tools of South Africa?

ko je napravio kameno oruđe u Južnoj Africi?

Brain size has historically played a key role

Veličina mozga je istorijski imala ključnu ulogu

in identifying a species as a tool user.

u identifikaciji vrste kao korisnika alata.

The idea is that you need to have a large brain

Ideja je da treba da imate veliki mozak

to have even the capacity to make stone tools.

da imate sposobnost da napravite kameno oruđe.

But that notion has been questioned.

Ali ta ideja je dovedena u pitanje.

Furthermore, Homo naledi, even with its small brain size,

Osim toga, Homo naledi, čak i sa svojom malom veličinom mozga,

has a hand-wrist morphology similar to other species

ima morfologiju ručnog zgloba sličnu drugim vrstama

that did make and use stone tools,

koje su pravile i koristile kameno oruđe,

suggesting it had the capability.

što ukazuje da su imali sposobnost.

With two species coexisting in Africa at 300,000 years,

Sa dve vrste koje su koegzistirale u Africi pre 300 000 godina,

we can no longer assume we know the maker of tools

ne možemo više da pretpostavljamo da znamo tvorce oruđa

at sites with no associated species.

na nalazištima koje nemaju veze ni sa jednom vrstom.

So where does Homo naledi fit in our human evolutionary lineage?

Gde se Homo naledi uklapa u lozu evolucije čoveka?

Who is it most closely related to?

Kome je najviše blizak?

Who did it evolve from?

Od koga je evoluirao?

We're still trying to figure all that out.

I dalje pokušavamo to da otkrijemo.

It's ironic, because paleoanthropologists are renowned

Ovo je ironično, jer paleoantropolozi su poznati

for having small sample sizes.

po tome što imaju mali uzorak.

We now have a large sample size,

Sada imamo veliki uzorak,

and more questions than answers.

a više pitanja nego odgovora.

Homo naledi has taught us,

Homo naledi nas je naučio,

has brought us a little bit closer

približio nas

to better understanding our evolutionary past.

boljem razumevanju naše evolutivne prošlosti.

So while Mrs. Ples will always hold a special place in my heart,

Mada će Gospođa Ples uvek imati posebno mesto u mom srcu,

she now shares that space with several thousand others.

ona sada deli taj prostor sa nekoliko hiljada drugih.

(Laughter)

(Smeh)

Thank you.

Hvala vam.

(Applause)

(Aplauz)