Clues to prehistoric times, found in blind cavefish | Prosanta Chakrabarty

Translator: Nika Kotnik Reviewer: Matej Divjak

Ichthyology,

Ihtiologija,

the study of fishes.

veda o ribah.

It looks like a big, boring word,

Izgleda kot velika, dolgočasna beseda,

but it's actually quite exciting,

a je pravzaprav precej vznemirljiva,

because ichthyology is the only "ology"

ker je ihtiologija edina "ologija",

with "YOLO" in it.

ki ima v sebi YOLO.

(Laughter)

(Smeh)

Now, to the cool kids in the audience,

Tisti v občinstvu, ki ste kul, že veste,

you already know, YOLO stands for "you only live once,"

da YOLO pomeni "samo enkrat se živi" ("you only live once")

and because I only have one life,

in ker imam samo eno življenje,

I'm going to spend it doing what I always dreamt of doing:

bom počel nekaj, o čemer sem vedno sanjal:

seeing the hidden wonders of the world and discovering new species.

da bi videl skrita čudesa sveta in odkrival nove vrste.

In to tudi počnem.

And that's what I get to do.

Now, in recent years, I really focused on caves for finding new species.

V zadnjih letih sem se osredotočil na jame, da bi našel nove vrste.

And it turns out, there's lots of new cavefish species out there.

In izkaže se, da je tam veliko novih vrst jamskih rib.

You just have to know where to look,

Samo vedeti moraš, kje iskati

and to maybe be a little thin.

in biti morda malo suh.

(Laughter)

(Smeh)

Now, cavefishes can tell me a lot about biology and geology.

Jamske ribe mi lahko veliko povedo o biologiji in geologiji.

They can tell me how the landmasses around them have changed and moved

Lahko mi povedo, kako so se zemeljske mase okrog njih spreminjale in premikale,

by being stuck in these little holes,

ker so obtičale v teh malih luknjah,

and they can tell me about the evolution of sight, by being blind.

in lahko mi nekaj povedo o evoluciji vida, ker so slepe.

Now, fish have eyes that are essentially the same as ours.

Ribe imajo oči, ki so pravzaprav enake našim.

All vertebrates do, and each time a fish species starts to adapt

Vsi vretenčarji jih imajo in vsakič, ko se vrsta ribe začne prilagajati

to this dark, cold, cave environment,

na temno, mrzlo jamsko okolje,

over many, many generations, they lose their eyes and their eyesight

čez mnogo, mnogo generacij, izgubijo oči in vid,

until the end up like an eyeless cavefish like this one here.

dokler ne končajo kot tale brezoka riba tule.

Now, each cavefish species has evolved in a slightly different way,

Vsaka vrsta jamske ribe se je razvila na rahlo drugačen način

and each one has a unique geological and biological story to tell us,

in vsaka nam lahko pove drugačno ekološko in geološko zgodbo

and that's why it's so exciting when we find a new species.

in zato je tako vznemirljivo, ko najdemo nove vrste.

So this is a new species we described, from southern Indiana.

Nova vrsta, ki smo jo opisali, je iz južne Indiane.

We named it Amblyopsis hoosieri, the Hoosier cavefish.

Poimenovali smo jo Amblyopsis hoosieri, Hoosier jamska riba.

(Laughter)

(smeh)

Its closest relatives are cavefishes in Kentucky,

Njeni najbližji sorodniki so jamske ribe iz Kentuckyja,

in the Mammoth Cave system.

v Mamutovi jami.

And they start to diverge when the Ohio River split them

In začeli sta se razlikovati, ko ju je reka Ohio razdelila

a few million years ago.

pred nekaj milijoni let.

And in that time they developed these subtle differences

V tem času so se razvile te subtilne razlike

in the genetic architecture behind their blindness.

in genetska arhitektura za njuno slepoto.

There's this gene called rhodopsin that's super-critical for sight.

Gen, imenovan rodopsin, je zelo pomemben za vid.

We have it, and these species have it too,

Mi ga imamo in vse te vrste tudi,

except one species has lost all function in that gene,

razen ene, ki je izgubila vso funkcijo tega gena,

and the other one maintains it.

in druge, ki jo je ohranila.

So this sets up this beautiful natural experiment

Tako to nastavi čudovit naravni eksperiment,

where we can look at the genes behind our vision,

kjer lahko pogledamo gene, odgovorne za naš vid,

and at the very roots of how we can see.

in korenine izvora našega vida.

But the genes in these cavefishes

A geni v teh jamskih ribah

can also tell us about deep geological time,

nam lahko povedo tudi nekaj o geoloških dobah

maybe no more so than in this species here.

in nobena tako kot tale vrsta tu.

This is a new species we described from Madagascar

To je nova vrsta, ki smo jo opisali v Madagaskarju

that we named Typhleotris mararybe.

in jo poimenovali Typhleotris mararybe.

That means "big sickness" in Malagasy,

V malgaškem jeziku to pomeni "velika bolezen",

for how sick we got trying to collect this species.

ker smo skoraj zboleli med iskanjem te vrste.

Now, believe it or not,

Verjemite ali ne,

swimming around sinkholes full of dead things

plavanje v luknjah polnih mrtvih stvari

and cave full of bat poop

in jami polni iztrebkov netopirjev

isn't the smartest thing you could be doing with your life,

ni najpametnejša stvar, ki jo narediš s svojim življenjem,

but YOLO.

ampak YOLO.

(Laughter)

(Smeh)

Now, I love this species despite the fact that it tried to kill us,

Rad imam to vrsto kljub temu, da nas je poskušala ubiti,

and that's because this species in Madagascar,

zato ker so najbližji sorodniki te vrste iz Madagaskarja

its closest relatives are 6,000 kilometers away,

6.000 kilometrov oddaljene

cavefishes in Australia.

jamske ribe iz Avstralije.

Now, there's no way a three-inch-long freshwater cavefish

Ni možno, da bi 7,5 centimetrska sladkovodna jamska ribica

can swim across the Indian Ocean,

preplavala Indijski ocean,

so what we found when we compared the DNA of these species

in ko smo primerjali DNK teh dveh vrst, smo ugotovili,

is that they've been separated for more than 100 million years,

da sta bili ločeni več kot 100 milijonov let,

or about the time that the southern continents were last together.

oziroma od takrat, ko so se južni kontinenti nazadnje stikali.

So in fact, these species didn't move at all.

Torej se ti dve vrsti sploh nista premaknili.

It's the continents that moved them.

Kontinenti so ju premaknili.

And so they give us, through their DNA,

Tako nam skozi svojo DNK dajo

this precise model and measure

natančni model in mere,

of how to date and time these ancient geological events.

kako določiti čas geoloških dogodkov.

Now, this species here is so new

Ta vrsta tu je tako nova,

I'm not even allowed to tell you its name yet,

da vam ne smem še povedati njenega imena,

but I can tell you it's a new species from Mexico,

lahko pa vam povem, da je to nova vrsta iz Mehike

and it's probably already extinct.

in je najbrž že izumrla.

It's probably extinct because the only known cave system it's from

Najbrž je izumrla, ker se je edini jamski sistem, kjer živi,

was destroyed when a dam was built nearby.

uničil, ko so v bližini zgradili jez.

Unfortunately for cavefishes,

Na njihovo smolo,

their groundwater habitat

je podvodno okolje jamskih rib

is also our main source of drinking water.

prav tako glavni vir naše pitne vode.

Now, we actually don't know this species' closest relative, yet.

Sedaj še ne poznamo najbližjega sorodnika te vrste.

It doesn't appear to be anything else in Mexico,

Zdi se, da ni ničesar v Mehiki,

so maybe it's something in Cuba,

tako da je najbrž nekje na Kubi

or Florida, or India.

ali na Floridi ali v Indiji.

But whatever it is, it might tell us something new about the geology

A karkoli je, nam bo morda povedalo nekaj novega o geologiji Karibov,

of the Caribbean, or the biology of how to better diagnose

ali o biologiji tega, kako bolje diagnosticirati

certain types of blindness.

določene vrste slepote.

But I hope we discover this species before it goes extinct too.

A upam, da odkrijemo to vrsto, preden še ta izumre.

And I'm going to spend my one life

In svoje življenje bom preživel

as an ichthyologist trying to discover and save

kot ihtiolog, poskušal bom odkriti in rešiti

these humble little blind cavefishes

te skromne male jamske ribe,

that can tell us so much about the geology of the planet

ki nam lahko toliko povejo o geologiji planeta

and the biology of how we see.

in biologiji našega vida.

Thank you.

Hvala.

(Applause)

(Aplavz)