The last living members of an extinct species - Jan Stejskal

Prevodilac: Aleksandar Bosnjak Lektor: Ivana Korom

In the savannahs of Kenya, two female northern white rhinos, Nájin and Fatu,

U kenijskim savanama, dve ženke severnih belih nosoroga, Najin i Fatu,

munch contentedly on the grass.

zadovoljno grickaju travu.

At the time of this video’s publication,

U vreme objavljivanja ovog videa,

these are the last two known northern white rhinos left on Earth.

ovo su dva poslednja poznata severna bela nosoroga na Zemlji.

Their species is functionally extinct—

Njihova vrsta je praktično izumrla -

without a male, Nájin and Fatu can’t reproduce.

bez mužjaka, Najin i Fatu ne mogu da se reprodukuju.

And yet, there’s still hope to revive the northern white rhino.

Ali ipak, i dalje ima nade da oživimo severne bele nosoroge.

How can that be?

Kako je to moguće?

The story starts about 50 years ago,

Priča počinje pre oko 50 godina,

when poachers began illegally hunting thousands of rhinos

kada su lovokradice počele ilegalno da love hiljade nosoroga

across Africa for their horns.

duž Afrike zbog njihovih rogova.

This, combined with civil wars in their territory,

Ovo, zajedno sa građanskim ratovima na njihovoj teritoriji,

decimated northern white rhino populations.

desetkovalo je populaciju severnih belih nosoroga.

Concerned conservationists began trying to breed them in captivity in the 1970s,

Zabrinuti konzervatori počeli su da ih odgajaju u zarobljeništvu 1970-ih godina,

collecting and storing semen from males.

sakupljajući i čuvajući spermatozoide mužjaka.

Only four rhinos were ultimately born through the ambitious breeding program.

Samo četiri nosoroga su na kraju rođena u ovom ambicioznom programu uzgoja.

Nájin, and her daughter Fatu were the last two.

Najin i njena ćerka Fatu su dva poslednja nosoroga.

In 2014, conservationists discovered that neither can have a calf.

U 2014. godini, konzervatori su otkrili da nijedna ne može da ima mladunčad.

Though Nájin gave birth to Fatu, she now has weak hindlegs,

Iako je Najin rodila Fatu, ona sada ima slabe zadnje noge,

which could harm her health if she became pregnant again.

što bi moglo da joj pogorša zdravlje ako zatrudni opet.

Fatu, meanwhile, has a degenerated uterine lining.

A Fatu, međutim, ima degenerisanu sluznicu materice.

Then, the last northern white rhino male of the species, Sudan, died in 2018.

Zatim, poslednji mužjak severnog belog nosoroga,

Sudan, umro je u 2018. godini.

But there was one glimmer of hope: artificial reproduction.

Ali bila je jedna svetla tačka: veštačka reprodukcija.

With no living males and no females able to carry a pregnancy,

Bez živih mužjaka i ženki koje mogu da izdrže trudnoću,

this is a complicated and risky process to say the least.

ovo je u najmanju ruku komplikovan i riskantan proces.

Though scientists had stored semen, they would have to collect the eggs—

Iako su naučnici sačuvali spermatozoide, morali bi da sakupe jajne ćelije,

a complex procedure that requires a female to be sedated for up to two hours.

što je komplikovan zahvat koji zahteva da se sedatira ženka na do dva sata.

Then, they’d create a viable embryo in the lab—

Onda, oni bi mogli da stvore uspešan embrion u laboratoriji,

something that had never been done before, and no one knew how to do.

nešto što nikada ranije nije bilo urađeno, i što niko nije znao kako.

Even that was just the beginning—

Čak i to je bio samo početak -

a surrogate mother of another rhino species

surogat majka druge vrste nosoroga

would have to carry the embryo to term.

bi nosila embrion do porođaja.

Females of a closely related species, the southern white rhino,

Ženke bliskog rođaka ove vrste, južnog belog nosoroga,

became both the key to developing a rhino embryo in a lab

postale su ključ za razvijanje embriona nosoroga u laboratoriji

and the leading candidates for surrogate mothers.

i vodeći kandidat za surogat majke.

Northern and southern white rhinos diverged about a million of years ago

Severni i južni beli nosorozi odvojili su se pre oko milion godina

into separate— though still closely-related— species.

u različite, premda usko povezane vrste.

They inhabit different regions, and have slightly different physical traits.

Nastanjuju različite oblasti, i imaju pomalo različite fizičke osobine.

In a fortunate coincidence, several female southern white rhinos

Sticajem srećnih okolnosti, nekoliko ženki južnog belog nosoroga

needed treatment for their own reproductive problems,

zahtevalo je lečenje za njihove reproduktivne probleme,

and researchers could collect eggs as part of that treatment.

a istraživači su mogli da sakupe jajne ćelije kao deo tog lečenja.

In Dvůr Králové Zoo in October 2015,

U zoološkom vrtu Dvur Kralove oktobra 2015. godine,

experts of IZW Berlin began collecting eggs from southern white rhinos

eksperti iz berlinskog IZD počeli su da sakupljaju jajne ćelije

južnog belog nosoroga

and sending them to Avantea, an animal reproduction laboratory in Italy.

i da ih šalju u Avanteu, laboratoriju za životnjsku reprodukciju u Italiji.

There, scientists developed and perfected a technique to create a viable embryo.

Tamo su naučnici razvili i usavršili tehniku stvaranja uspešnog embriona.

Once they mastered the technique,

Čim su savladali tehniku,

researchers extracted Nájin and Fatu’s eggs on August 22, 2019

istraživači su izvadili jajne ćelije Nadjni i Fati 22. avgusta 2019. godine

and flew them to Italy.

i poslali ih u Italiju.

Three days later, they fertilized the eggs with sperm

Tri dana kasnije, oplodili su jajne ćelije spermatoizoidom

from a northern white rhino male.

mužjaka severnog belog nosoroga.

After another week, two of the eggs made it to the stage of development

Nakon još jedne nedelje, dva zigota dospela su do stadijuma razvoja

when the embryo can be frozen and preserved for future.

kad embrion može da se zamrzne i sačuva za budućnost.

Another collection in December 2019 produced one more embryo.

Još jednim sakupljanjem u decembru 2019. godine

dobio se još jedan embrion.

As of early 2020, the plan is to collect Nájin and Fatu’s eggs three times a year

Početkom 2020. godine plan je da se sakupljaju jajne ćelije

Najini i Fatu tri puta godišnje ako su dovoljno zdrave.

if they’re healthy enough.

In the meantime, researchers are looking for

U međuvremenu, istraživači traže

promising southern white rhino surrogate mothers—

izgledne surogat majke južnih belih nosoroga,

ideally who’ve carried a pregnancy to term before.

idealno bi bilo da s u prošlosti izdržale trudnoću.

The surrogacy plan is somewhat of a leap of faith—

Plan za surogat majke je donekle korak u nepoznato,

southern and northern white rhinos have interbred

i južni i severni beli nosorozi ukrstili su se

both during the last glacial period and more recently in 1977,

tokom poslednjeg glacijacijskog perioda i skorije 1977. godine,

so researchers are optimistic a southern white rhino

tako da su istraživači optimistični da južni beli nosorog

would be able to carry a northern white rhino to term.

može da podnese trudnoću sa severnim belim nosorogom.

Also, the two species’ pregnancies are the same length.

Takođe, trudnoće ove dve vrste iste su vremenske dužine.

Still, transferring an embryo to a rhino is tricky

Ipak, prenošenje embriona u nosoroga je riskantno

because of the shape of the cervix.

zbog oblika grlića materice.

The ultimate goal, which will take decades,

Krajnji cilj, za koji su potrebne decenije,

is to establish a breeding population of northern white rhinos

jeste da se osnuje populacija za odgoj severnih belih nosoroga

in their original range.

u njihovoj originalnoj oblasti.

Studies suggest that we have samples from enough individuals

Studije sugerišu da imamo dovoljno individualnih uzoraka

to recreate a population with the genetic diversity the species had a century ago.

da se opet stvori populacija sa genetskom raznovrsnošću

koju je ova vrsta imala pre sto godina.

Though the specifics of this effort are unique,

Iako su pojedinosti ovih napora jedinstvene,

as more species face critical endangerment or functional extinction,

što se više vrsta suočava sa kritičnom ugroženošću ili istrebljenjem,

it’s also an arena for big questions:

takođe je arena za velika pitanja:

do we have a responsibility to try to bring species back from the brink,

da li imamo odgovornost da pokušamo da izvedemo vrste van opasnosti,

especially when human actions brought them there in the first place?

naročito pošto su ih ljudske akcije dovele do toga?

Are there limits to the effort we should expend

Postoje li ograničenja napora koje bi trebalo da proširimo

on saving animals threatened with extinction?

kako bismo spasili životinje kojima preti izumiranje?