You Can Change Your DNA. Octopus does change it s RNA.
Changing DNA Through Intention
The team returned in 2017 with an even more startling finding - at least two species of octopus and one cuttlefish do the same thing on a regular basis. To draw evolutionary comparisons, they also looked at a nautilus and a gastropod slug, and found their RNA-editing prowess to be lacking.
"This shows that high levels of RNA editing is not generally a molluscan thing; it's an invention of the coleoid cephalopods," said co-lead researcher, Joshua Rosenthal of the US Marine Biological Laboratory.
The researchers analysed hundreds of thousands of RNA recording sites in these animals, who belong to the coleoid subclass of cephalopods. They found that clever RNA editing was especially common in the coleoid nervous system.
"I wonder if it has to do with their extremely developed brains," geneticist Kazuko Nishikura from the US Wistar Institute, who wasn't involved in the study, told Ed Yong at The Atlantic.
It's true that coleoid cephalopods are exceptionally intelligent. There are countless riveting octopus escape artist stories out there, not to mention evidence of tool use, and that one eight-armed guy at a New Zealand aquarium who learned to photograph people. (Yes, really.)
So it's certainly a compelling hypothesis that octopus smarts might come from their unconventionally high reliance on RNA edits to keep the brain going.
"There is something fundamentally different going on in these cephalopods," said Rosenthal.
But it's not just that these animals are adept at fixing up their RNA as needed - the team found that this ability came with a distinct evolutionary tradeoff, which sets them apart from the rest of the animal world.
In terms of run-of-the-mill genomic evolution (the one that uses genetic mutations, as mentioned above), coleoids have been evolving really, really slowly. The researchers claimed that this has been a necessary sacrifice - if you find a mechanism that helps you survive, just keep using it.
"The conclusion here is that in order to maintain this flexibility to edit RNA, the coleoids have had to give up the ability to evolve in the surrounding regions - a lot,"