In the recent sci-fi film Arrival, “Heptapods” are the alien species that visit us.
Depicted as giant seven-legged octopus-like creatures, they seem like a pretty believable choice for an extraterrestrial life form.
The reason for this is we have long thought of octopuses as “alien-like” due to their high level of intelligence, interesting behaviour, and freaky appearance.
In the past, scientists have discovered that octopuses are capable of solving puzzles, using tools, escaping from aquariums, opening jars and mimicking their environments.
However, a new discovery has proved that these magnificent eight-legged creatures can do something else: edit their own genes.
In a study published in the journal Cell, scientists found that octopuses – and other cephalopods including squid and cuttlefish – do not obey the normal rules of genetic information.
In order to understand this, we need to first know the difference between RNA and DNA. If DNA is the blueprint of genetic instructions established at your conception, RNA is the thing that translates that design into the building of your body.
So when your DNA tells your body to produce certain proteins, the RNA is the thing that makes it happen.
However, sometimes RNA may rebel, edited by enzymes to produce a different protein than the one dictated by the DNA.
Although RNA editing in mammals was discovered about 25 years ago, scientists have observed that organisms use it sparingly.
As noted by Wired, we can surmise that evolutionarily speaking, “Mother Nature gave RNA editing a try, found it wanting and largely abandoned it”.
But not so for cephalopods.
According to the study, cephalopods used their tweaked RNA to generate new proteins. Yeah, but why?
One reason may simply be survival. In a previous study, it was discovered that octopuses use RNA editing to keep their bodies warm in the freezing cold waters of the Antarctic.
A grander idea is that they do it to make themselves smarter. Eli Eisenberg, a co-author of the study, told The Washington Post that the RNA recoding offered “tantalising hints toward the hypothesis that extensive recoding might have contributed to the exceptional intelligence” of these creatures.
Despite the apparent advantages, RNA editing does have its downsides. Although RNA editing gives cephalopods more flexibility, they are trading off the classic hardwired evolutionary method of change by mutation. In other words, RNA editing may be better short term, but DNA mutations seem to favour life in the long run.
But RNA makes sense for cephalopods that typically live fast and die young. They lead mostly solitary lives and have to figure things out for themselves. In that case, RNA editing to gain quick smarts and environmental adaptability is understandable.
At this point, scientists still need to learn more about how octopuses have evolved via RNA editing. But one thing that is for sure: these creatures are amazing and like nothing else on this planet. Think about that next time your order the squid.