How did squids become so smart?
New study finds cephalopods evolved differently from other animals, including humans
Cephalopods – a family of marine animals that includes octopuses, squid and cuttlefish – are extraordinarily smart for underwater creatures. You might have seen videos of them opening jars, using various objects as tools, or even correctly predicting the future, as Paul the octopus did with game results for the 2010 World Cup.
But how did these animals develop such a high level of intelligence? A new study from Eli Eisenberg from Tel Aviv University’s Raymond and Beverly Sackler School of Physics and Astronomy, done in collaboration with Joshua Rosenthal from the Marine Biological Laboratory in Woods Hole, has found that these spineless species use a different path to complexity at the molecular level, which may have contributed to their behavioral sophistication.
Don’t shoot the messenger
For most animals – including humans – genetic mutation happens through the DNA. Scientists believe that evolution occurred through these mutations, which created different traits, and eventually only the traits beneficial for survival and reproduction stuck around.
For squids, octopuses and cuttlefish, however, it seems the experimentation happened with RNA, the “messenger” that connects the DNA code and the parts of our cells that create proteins based on that code. According to Dr. Eisenberg, experimenting with RNA means a much slower pace of genomic evolution, but cephalopods have apparently preferred to make this sacrifice in return for the benefits RNA changes have allowed them. Forgoing a large fraction of genomic mutations is a big price to pay, suggesting the functional implications of RNA editing must be immense.
Therefore, Dr. Eisenberg hypothesizes that this form of “editing” might have played a role in the development of the impressive neural network and complex brain of cephalopods, leading to the sophistication we see in the behavior of these animals.
What squids can teach us
Dr. Eisenberg’s discovery has made waves around the world. With his study recognized by leading scientists in the field as well as non-scientific publications like the New York Times, his findings could have a profound effect.
Extrapolating from the way squids “edit” their genetics could give us new ways to affect the world. There are currently barriers to manipulating human DNA, but RNA is far less dangerous to deal with. This could one day help us change our own genetics or even develop cures for chronic illnesses.