Mhariri wa Kujihariri

Asubuhi ya sita, Chiara alitengeneza kahawa kwa ajili yao wote wawili na kuketi karibu na tanki. Pasta alikuwa amening'inia kichwa chini kutoka kwenye kona ya kioo. Mwili wake ulipiga polepole. Mikono yake ilizunguka kama ua linaloelea taratibu.

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

"Kuna jambo moja zaidi nataka kukuambia," Chiara alisema, "na nataka kulisema polepole, kwa sababu ni jambo la kushangaza zaidi kuhusu pweza ninalojua."

"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 alikaa kwenye ukingo.

Polly perched on the rim.

"Pweza wanaweza kuhariri RNA yao wenyewe papo hapo," Chiara alisema. "Hakuna mnyama mwingine anayefanya hivi kwa kiwango wanachofanya."

"Octopuses can edit their own RNA in real time," Chiara said. "No other animal does this at the rate they do."

DNA ni mpango wa muda mrefu wa mnyama. Haibadiliki sana katika maisha. RNA ni nakala inayofanya kazi. Seli hufanya RNA kutoka kwa DNA inapohitaji kujenga protini. Kwa wanyama wengi, RNA inalingana kabisa na DNA.

DNA is the long-term blueprint of an animal. It does not change much in a lifetime. 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 exactly.

Kwa pweza, RNA haifanani. Wakati RNA inatengenezwa, seli huandika upya sehemu zake. Mabadiliko haya mengi hutokea katika sehemu zinazojenga mfumo wa neva.

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 that build the nervous system.

"Kwa nini?" Chiara alisema. "Uhariri wa RNA ni wa kubadilika. Mabadiliko ya DNA siyo. Pweza anaweza kurekebisha mfumo wake wa neva kulingana na joto la maji au kemia ya chakula chake. Inapanga ubongo wake mwenyewe. Gharama ni kwamba spishi yenyewe haijaweza kubadilika sana. Wamelipia kubadilika kwa muda mfupi kwa utulivu wa muda mrefu."

"Why?" Chiara said. "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 its food. It tunes its own brain. The cost is that the species itself has not been able to evolve much. They paid for short-term flexibility with long-term stability."

Pasta alielea. Ngozi yake karibu na macho ilibadilika kupitia rangi nyororo za pinki na kahawia hafifu.

Pasta drifted. Her skin near the eyes flickered through soft pinks and pale browns.

"Kila pweza mmoja mmoja," Chiara alisema, "ni mnyama tofauti kidogo na kila mwingine, kwa njia ambayo mimi na wewe na kasuku wengine siyo. DNA ile ile, lakini mashine ya kufanya kazi inajengwa upya, kila maisha, kwa maji hayo na chakula hicho."

"Each individual octopus," Chiara said, "is a slightly different animal from every 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."

Polly alifikiria kuhusu ubongo wake mwenyewe. Ulikuwa umejengwa mara moja, jinsi ubongo mwingi unavyojengwa, na sasa ulikuwa wake tu. Hakumwonea Pasta wivu kwa kubadilika kwake. Lakini alipenda sana kujua kwamba wanyama kama Pasta walikuwepo.

Polly thought about her own brain. 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.