We already knew octopuses and other cephalopods were pretty awesome. But they just got a whole lot more awesome.
Published in the journal Cell, scientists have found that cephalopods are able to edit their RNA, at the expense of evolution in their genomic DNA. In other words, they are able to rapidly change on the cellular level to suit their environment, rather than relying on the slow evolution of DNA to make changes.
The study was led by Joshua Rosenthal of the Marine Biological Laboratory (MBL), Massachusetts and Eli Eisenberg and Noa Liscovitch-Brauer of Tel Aviv University, Israel. Together they had previously discovered that squids have an unusually high rate of editing their RNA. In this new research, they found similarly high levels in three other cephalopod species – two octopuses and one cuttlefish.
In most species, RNA editing is minimal, such as in humans or fruit flies where only a fraction of 1 percent of RNA is recoded. We evolve by editing our DNA over time, using RNA – essentially a copy of DNA – to make proteins that pretty much run everything in our bodies.
But cephalopods seem to be different. They are continuously editing their RNA, making changes to their biology on the fly, rather than relying on DNA evolution. This was particularly apparent in coleoids, the soft-bodied cephalopods.
DNA is the blueprint of our bodies. ktsdesign/Shutterstock
"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," Rosenthal said in a statement. "Mutation is usually thought of as the currency of natural selection, and these animals are suppressing that to maintain recoding flexibility at the RNA level."
As Scientific American notes, this extensive RNA editing may have helped minimize changes in the DNA of cephalopods over many years – and it could mean they have been around much longer than thought.
No one is quite sure why cephalopods are editing their RNA so rapidly. It may, though, explain how these creatures become relatively smart in such a short amount of time, living only for a few years. They can solve puzzles, open jars, camouflage themselves in unique ways, and might even be using other sea creatures as weapons to catch prey.
“Perhaps RNA editing, adopted as a means of creating a more sophisticated brain, allowed these species to use tools, camouflage themselves, and communicate,” notes Wired.
One thing’s for sure, these creatures are getting more and more impressive. The fact they can essentially evolve on the fly to suit their environment is, well, pretty amazing.