Editor sám seba

Na šiesty deň ráno Chiara pripravila kávu pre obe a posadila sa na stoličku vedľa akvária. Pasta visela dolu hlavou z rohu skla, jej telo sa jemne pulzovalo. Ramená sa okolo nej vznášali ako pomalý kvet.

On the sixth morning, Chiara made coffee for both of them and sat down in the chair beside the tank. Pasta was hanging upside down from a corner of the glass, the bell of her body pulsing gently. Her arms drifted around her like a slow flower.

"Je tu ešte jedna vec, ktorú ti chcem povedať," povedala Chiara, "a chcem ju povedať pomaly, pretože je to tá najzvláštnejšia vec o chobotniciach, ktorú poznám."

"There is one more thing I want to tell you," Chiara said, "and I want to tell it slowly, because it is the strangest thing about octopuses I know."

Polly sa usadila na okraji.

Polly perched on the rim.

"Chobotnice dokážu upravovať svoju vlastnú RNA v reálnom čase," povedala Chiara. "Robia to neustále. Žiadne iné zviera to nerobí v takom rozsahu ako chobotnice a niekoľko príbuzných hlavonožcov."

"Octopuses can edit their own RNA in real time," Chiara said. "It is something they do constantly. No other animal does this at the rate that an octopus and a few related cephalopods do."

Zastavila sa. Vedela, že ďalšia časť si vyžaduje opatrnosť.

She paused. She knew the next part required care.

DNA je dlhodobý plán zvieraťa. Veľa sa nemení. RNA je pracovná kópia. Bunka vytvára RNA z DNA, keď potrebuje postaviť proteín. U väčšiny zvierat sa RNA takmer presne zhoduje s DNA.

DNA is the long-term blueprint of an animal. It does not change much. RNA is the working copy. The cell makes RNA from DNA when it needs to build a protein. In most animals, the RNA matches the DNA almost exactly.

U chobotníc sa RNA nezhoduje. Keď sa RNA vytvára, bunka prepisuje jej časti. Väčšina týchto úprav sa deje v častiach genómu, ktoré budujú nervový systém. Nervový systém chobotnice je obzvlášť neustále budovaný a prestavovaný týmito úpravami.

In octopuses, the RNA does not match. As the RNA is being made, the cell rewrites parts of it. Most of these edits happen in the parts of the genome that build the nervous system. The nervous system of an octopus, in particular, is built and rebuilt constantly with these edits.

"Prečo?" povedala Chiara, skôr než Polly mohla položiť otázku. "Máme teóriu. Úprava RNA je reverzibilná. Mutácia DNA nie je. Chobotnica môže prispôsobiť svoj nervový systém v reakcii na teplotu vody alebo chémiu potravy, ktorú konzumuje. Môže si naladiť svoj vlastný mozog za pochodu. Cena je, že samotný genóm, dlhodobý plán, sa nemohol veľmi vyvíjať. Druh uviazol s rovnakou DNA, viac-menej, po desiatky miliónov rokov. Zaplatili za krátkodobú flexibilitu dlhodobou stagnáciou."

"Why?" Chiara said, before Polly could ask. "We have a theory. RNA editing is reversible. DNA mutation is not. An octopus can adjust its nervous system in response to the temperature of the water or the chemistry of the food it eats. It can tune its own brain on the fly. The cost is that the genome itself, the long-term blueprint, has not been able to evolve much. The species is stuck with the same DNA, more or less, for tens of millions of years. They paid for short-term flexibility with long-term stagnation."

Polly sledovala, ako sa Pasta vznáša. Telo chobotnice pomaly pulzovalo. Koža blízko očí prechádzala jemnými pulzmi ružových a bledohnedých odtieňov.

Polly watched Pasta drift. The octopus's body pulsed slowly. The skin near the eyes flickered through a soft pulse of pinks and pale browns.

"Každá jednotlivá chobotnica," povedala Chiara, "je trochu iné zviera ako každá iná, spôsobom, akým ty a ja a iné papagáje nie sme. Rovnaká DNA. Ale pracovný mechanizmus je postavený nanovo, každý život, pre tú vodu a tú potravu. Sú to individuálne mozgy spôsobom, akým možno žiadne iné zviera na Zemi nie je."

"Each individual octopus," Chiara said, "is a slightly different animal from each other one, in a way that you and I and other parrots are not. The same DNA. But the working machinery is built fresh, every life, for that water and that food. They are individual brains in a way that perhaps no other animal on Earth is."

Vypila svoju kávu.

She drank her coffee.

"Je to tiež dôvod," povedala, "prečo dve chobotnice, ktoré dostanú rovnaký labyrint, ho môžu vyriešiť úplne odlišnými spôsobmi. Pasta vyriešila labyrint s dvoma spolupracujúcimi ramenami. Mali sme minulý rok inú chobotnicu, ktorá použila tri. Mali sme ďalšiu, ktorá čakala hodinu a potom šla priamo s telom. Nerobia to isté riešenie s rovnakým mozgom. Každá ho rieši s mozgom, ktorý si sama vytvorila."

"It is also why," she said, "two octopuses given the same maze can solve it in completely different ways. Pasta solved the maze with two arms cooperating. We had another octopus last year who used three. We had another who waited an hour and then went straight in with the body. They are not solving the same problem with the same brain. They are each solving it with the brain they have made for themselves."

Pastino oko sa otvorilo a zatvorilo. Ramená sa vznášali.

Pasta's eye opened and closed. The arms drifted.

Polly premýšľala o svojom vlastnom mozgu. Nebol upravovaný v reálnom čase. Bol postavený raz, tak ako väčšina mozgov, a teraz bol jednoducho jej. Nezávidela Paste tú flexibilitu. Ale veľmi sa jej páčilo vedieť, že existujú zvieratá ako Pasta.

Polly thought about her own brain. It had not been edited in real time. It had been built once, the way most brains are built, and was now simply hers. She did not envy Pasta the flexibility. But she liked very much knowing that animals like Pasta existed.

Chiara vstala. "Musím ísť napísať grant," povedala. "Zostaň s ňou ráno, ak chceš."

Chiara stood up. "I have to go write a grant," she said. "You stay with her for the morning, if you want."

Polly zostala.

Polly stayed.