How the Octopus Changes Color in Seconds and We Remake Our Minds Every Moment… Then Evolve Every Generation
“Any man could, if he were so inclined, be the sculptor of his own brain.” ― Santiago Ramón y Cajal, 1897
Maybe you’re one of those people who are smart in some ways and but clueless in others? No worries, you’re in good company. Like savvy real estate developers, we all subdivide our brains, building on lots with the best views and and selling off what’s left. From recent discoveries in neuroscience, we now know that our developer brains share both molecular and behavioral strategies with the consistently clever octopus. We’re both resourceful and flexible, great problem-solvers, and constantly changing our colors to fit situations and surroundings most vital to us. We both focus on what to learn and remember, then gradually forget the rest. To do all that we both make slight adjustments to our RNA and DNA every millisecond. But the octopus, having one central brain, eight peripheral brains, and three hearts wins first prize for “Mind/Body Connections.”
“The Nobel Prize–winning biologist Sydney Brenner once said that octopi were the first intelligent beings on Earth. New findings could prove he was right.” – Clifton Ragsdale, neurobiologist (and his team at the University of Chicago were first to unravel the octopus genome, 2015.)
Deep below the surface of octopus brain cells, at the molecular level, this cephalopod modifies its RNA with over a hundred forms of “edits” that continually fine tune the functional units of its DNA, its genes. Small molecular “edits” or attachments to its RNA record crucial events and strategies that can be called up in the future. Beginning some 530 million years ago, the octopus first latched onto RNA-editing (epitranscriptomics) and fast-changing skin proteins and hasn’t let go since. Today, the octopus still uses RNA-editing, or “epitranscriptomics,” to remember what’s best. Man, a relative newcomer to nucleotide modifications, relies more upon DNA-editing, or “epigenetics.”
The “Orchestration” of Gene Expression
Barely four years old, and based upon research from octopus neurons, the RNA-editing science of “Epitranscriptomics” has identified over a hundred RNA-editing mechanisms that allow the octopus to imprint its best and brightest survival skills and recall them later when their life depends on it. At the same time, RNA-edits, like DNA-edits, are reversible. Octopus stay open to changing their ways with new RNA-edits while leaving the basics of their DNA genome permanently intact.
Only within the last six million years or so has man caught up in RNA/DNA-editing brain game, rapidly evolving a wide range of adaptive intelligence through elaborate epigenetic mechanisms of DNA-editing. Long before man though, 530 million years longer, in fact, the octopus had already developed a repertoire of street smarts through RNA-editing. Maybe because our family trees diverted some 700 million back and because of basic differences between RNA and DNA editing, octopus intelligence has been described as weird or alien.
Still, we both use an arsenal of nucleotide-editing techniques to imprint behavioral characteristics onto our DNAs and RNAs and improve our chances of survival. This molecular intelligence makes us lifelong learners who stockpile useful information, then pass on our sets of new, improved acquired characteristics and the “edits” that create them to the next generation. Now that’s evolution, and it works every instant and far faster than natural selection.
As acquired molecular imprints and their corresponding behaviors prove beneficial in the long run, these RNA-edits and DNA-edits stick like glue, transitioning slowly into more permanently useful genes. Just as “Neurons that fire together wire together,” (DO Hebb, 1949) the more that DNA and RNA markers maintain their benevolence over successive generations the more they increase their own chances of survival. From octopus to man, each generation chooses what works best and what doesn’t, what tags and markers to keep and what to discard, then records those choices onto RNA and DNA. In this sense, Darwin was only partially right. While environments may be selecting out the most adaptive individuals, it’s our thinking that selects the most beneficial thoughts, behaviors, and molecular imprints that come and go as attachments to our RNAs and DNAs every second and gets passed on every generation.
While Darwin’s Theory of Natural Selection relies on random mutations and millenniums of trials, errors, and competitions, RNA and DNA-editings are the direct result of the momentary choices we make. Our experiences and our choices evolve us over just a few generations. Through repeating learned behaviors and strategies over generations, we create acquired traits, acquired behaviors, which then become acquired genes!
Even though octopus have 33,000 protein-coding genes and man has only 20,500, our use of DNA-editing affords us a wider range of intelligences, and a faster evolution suited to the more transient habitats we face on land. By using predominantly DNA-edits rather than RNA-edits man has developed a greater “orchestration of genes” playing ever-changing music.
Creating A Frame of Mind
Even though we rate intelligence as one number, one IQ score, we know that different people and different cultures have vastly different intelligences. Tribesmen raised in Amazonia know plants, rivers, and how to aim a blowgun while New Yorkers know delis, subways, and how to catch a cab. That’s adaptation, a process that might slow some with age but keeps going for life. Using tiny molecules that attach and unattach to our DNA and RNA, even identical twins modify their genes differently, tinkering with the fine print. Like the octopus, we change our colors as needed. In addition, both man and octopus move their genes around, mixing and matching their sequence. An assortment of “jumping genes,” or transposons, jump from one place to another along vast stretches of our chromosomes. What directs genes to make these bold moves?
“Most people assume that our genes shape us—our behavior and our brain anatomy. Kandel’s work shows that when we learn our minds also affect which genes in our neurons are transcribed. Thus we can shape our genes, which in turn shape our brain’s microscopic anatomy.” –― Norman Doidge, The Brain That Changes Itself
Is intelligence a measure not only of how fast we think but how fast we adapt?
Documented case histories show that a woman born with half a brain can rewire that half to work as a whole; blind people can learn to see; learning disorders can be cured; IQs can be raised; aging brains can be rejuvenated; stroke patients can learn to speak again; children with cerebral palsy can learn to move with more grace; depression and anxiety disorders can be successfully treated; and lifelong character traits can be reversed.
RNA and DNA-editing give us this amazing ability to create the frame of mind we want. Recent discoveries by an international team of geneticists have identified 52 genes linked to intelligence. (Nature Genetics, May, 2017). These geneticists believe that thousands more genes for intelligence will soon be deciphered as well. With 700-plus new neural stem cells being born everyday in our hippocampus and this myriad of genes for intelligence we create a smarter, more evolved “frame of mind” for ourselves – all within the six weeks it takes for neural stem cells to mature, migrate into place, and create new circuits.
“There is nothing either good or bad, but thinking makes it so.” – Hamlet
By adding or subtracting small molecular tags or markers to RNAs and DNAs, and moving our genes around at will, we re continually editing our nucleotide software – redirecting, amplifying, and gradually recreating our genome. We are self-evolving. Tags and markers on our RNA and DNA provide minute, and sometimes major, recalibrations of gene expression, producing what neuroscientists call “experience-dependent plasticity.”
The “Experience-Dependent Plasticity” of RNA-editing
“This particular issue is not that different from the early days of the histone-modification field.” – Howard Chang, Stanford University
The RNA Institute at the University at Albany now maintains a database for 109 (currently known) RNA-modifications, essential to learning and memory – a library of “experience-dependent” directives along our genes! In the octopus, “experience-dependent plasticity,” or learning, translates daily into inventive camouflages, quick-change disguises, artistic contortions, stealth-mode behaviors, deft imitations, uncanny problem-solving, and a walk-in-closetful of craftiness.
That so many more RNA-modifications than DNA-modifications have been identified in the “experience-dependent” octopus leads researchers to believe that modified RNAs could be more responsible for some types of brain plasticity than epigenetic DNA-markers and histone protein tags. From bacteria to octopus to man, RNA-edited-tags are involved in processes as diverse as cell differentiation and forms of cancer.
DNA-editing, more commonly used by vertebrates like ourselves with much larger (and more central) brains, allows for fast evolution to a wider range of changing habitats, while RNA-editing allows for ever-changing proteins designed to immediately mimic more stable habitats. According to Joshua Rosenthal at the Marine Biological Laboratory, “the octopus and other Coleoid cephalopods are the only animal lineage that has really achieved behavioral sophistication other than vertebrates.”
“There is something fundamentally different going on in these cephalopods,” notes Rosenthal. “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.” Squid, cuttlefish, and octopus routinely edit more than 60% of their RNA.
Edited-RNAs probably serve as metabolic signposts for the manufacture of specific “spines” along neural dendrites, the micro-neuroanatomy responsible for learning and memory. Trillions of these minute protrusions, called dendritic spines, come and go within days, forging or forgetting our experiences. Like searching tentacles and suckers, branches of dendrites grow hundreds to thousands of spines, each spine making of thousands of connections. New spines and new connections are continuously driven by subconscious commands, especially while we sleep.
Born Ready! No Parenting Required!
Thanks to neuroscientists at Tel Aviv University, led by Joshua Rosenthal and Eli Eisenberg, and their work with octopus neurons, we now know that RNA-editing provides an extensive library of instinctual learning at birth. Octopus are born ready! Even the youngest of octopus adapts quickly – with no parenting involved!
Although they can be easily found showcased as tasty tapas or gourmet entrees in eateries across the Iberian peninsula, the 300 or so species of octopus know how to escape detection in their ocean habitats, and they do so beautifully. From sunny turquoise waters to frigid arctic depths, they change colors in milliseconds, skillfully blending their bulbous mainframe (three hearts, no spine, and eight powerful tentacles) in with their seafloor surroundings. Talented and curious, they also play, use tools, grow back lost tentacles, come equipped with distinct personalities, and devote an entire area of their brain to learning and remembering. “They learn information and use what they learn,” says Jennifer Mather, comparative psychologist at the University of Lethbridge, who has studied the shape-shifting and polychromatic cephalopod for 35 years.
At the molecular level, inside each neuron, the octopus nurtures a kaleidoscope of RNA-editing techniques that produce instant and colorful adjustments to its immediate needs.
“Biology gives you a brain. Life turns it into a mind.” ― Jeffrey Eugenides
A Brain for Every Arm
By vertebrate standards, the central “brain” of the octopus is considered small, 20x smaller in fact, than man’s. As compared to the roughly 86 billion neurons in the human brain, only a third of the octopus’ ~500 million neurons reside in their centralized brain. Still, it’s a large brain in relation to its body size. The other two-thirds of octopus neurons form a confederacy, an alliance of ganglia, or mini-brains, with one at the base of each arm. These eight peripheral brains can work independently or in unison, to sense danger or food, explore, mentally map their environments, strategize, makes independent decisions, and take action with what one science writer calls “an eerily alien intelligence.”
But octopus are not aliens, they just have eight more brains than us… and two more hearts. With extensive RNA-editing they amplify their genes in unique ways. At neuroanatomical and electrophysiological levels, however, neuroscientists have discovered that octopus and man learn and remember in much the same way. From an octopus point of view, it’s taken that johnny-come-lately man over 600 million years to catch up.
“Cephalopods have paralleled the vertebrates, micro-miniaturizing neurons to pack more cells into a given space. They’ve also built layered structures into their brains, and thrown the tissue up into folds that increase surface area, much as the vertebrate cortex has,” says biologist PZ Meyers at the University of Minnesota.
Much like the mammalian hippocampus, the vertical lobe (VL) and the median superior frontal lobe (MSF) of the octopus central brain combine to perform associative learning tasks. Octopus and man share similar versions of short-term and long-term memory, patterns of sleep, and have specific neurons that recognize specific individuals, maybe Jennifer Aniston. Except for a slot pupil, their two eyes are like ours.
In a broad sense, just as our immune system produces a variety of customized cells to defend against the microbial invaders that attack us, octopus skin has developed specialized skin proteins that produce immediate camouflage protection against predators. Having left behind their bulky mollusc shells many millions of years back in evolution, octopus defend themselves with cunning obfuscation. Sensing danger, they instantly adjust skin patterns, textures, and shapes to blend in beautifully with just about anything – from multi-colored coral to elegant sea fans to dark-green seaweed. To confront a transgressor they inflate/enlarge their profiles and turn angry colors. If that doesn’t work they dart off with water-jet propulsion, leaving a black and toxic cloud of ink in their wake.
Using their exceptional eyesight (but color-blind vision) octopus mimic their surroundings, squeezing varying muscles to mix just a palate of pigments (black, brown, orange, red, or yellow) from chromatophores, textures, and opacity and reflectiveness from iridiophores. How does the color-blind octopus do all this? “New evidence suggests cephalopods might be able to see with their skin.” – Sy Montgomery, The Soul of an Octopus
Among their many talents, octopus can also jet out a suffocating cloud of black ink to cover escape, or inject tetrodotoxin venom through the shells of clammed-up mollusk meals. Bites from octopus are poisonous to a degree, but getting “beaked” by the petite Australian Blue-Ringed Octopus can be deadly.
Artful Dodgers, Gifted Contortionists, and Great Escape-Artists
“The measure of intelligence is the ability to change” – Albert Einstein
In addition to magically color-shifting, shape-shifting, and contorting themselves to look like something they’re not, some octopus swim the extra mile. Apart from changing their bodies to look like more dangerous neighbors, venomous sea snakes or poisonous lionfish for example, some octopus complete the illusion by mimicking the movements and behaviors of neighbors, as well.
Probably the greatest contortionist-illusionist known to man, the Indonesian Mimic Octopus, or Thaumoctopus mimicus, can morph into a lionfish, a jellyfish, a shrimp, a crab, flounder, stingray – a total of 15 different organisms and counting! The envelope please! This year’s award for Most Illustrious Intelligence goes to … Thaumoctopus mimicus!
Not content with mere imitation, multi-tasking, hiding out, or just fitting in, octopus are also perseverant problem-solvers. If a crab meal waits in a bottle with a child-proof cap, this cephalopod accepts the challenge then takes its time, up to an hour, learning to open its lunchbox, but only five minutes to repeat the process the next day.
Difficult to confine to quarters, octopus are reported to keep both eyes peeled before breaking the rules. First, they learn their keeper’s schedule. Once their warden has left for the night, eight tentacles begin to slide. Then, these master escape-artists know to squelch the incriminating evidence. By squirting water long distances at lightbulbs they short-circuit nearby breakers. The lights go out and security cameras, too. Then, they devise ingenious methods to slip away for a midnight rendez-vous in fish tank next door. By the time the keeper returns and discovers the missing mackerel the octopus sits back in its lair, looking up with a “Who me?” poker-face.
Over-thinking their intelligence? Ask Jean Boal, a behavioral researcher at Millersville University, who works with octopus. Just once, she delivered stale squid to octopus in tanks along her feeding-time route. After making her rounds, Boal returned to one tank with an octopus staring at her while holding up the stale squid as if asking, ”Seriously?” With both eyes locked in on her, the octopus then stalked over to an outflow duct and carefully stuffed the stale squid down the drain with eight-armed disdain. It had waited for Boal to return to the front of its tank to deliver its visual message: “This stuff stinks. We food-strike like Mahatma Gandhi until we get some fresh squid.”
Communicative but also crafty, octopus fashion shelters, tools, and levers from whatever’s handy. Their powerful beak, eight arms, and ~2,000 suckers (each sucker has its own ~10,000 neurons) can act independently or in unison, to unhinge the toughest clam or grapple the mysteries of a Rubic’s Cube. With their central brain and oversized optic lobes keeping track of whatever the other two-thirds of their neurons have in mind at the moment, octopus benefit from both centralized and localized nervous systems. Sure, octopus boast eight-arms, ten thousand-suckers, deceptive camouflage, and a trenchcoat of slippery tricks up their eight sleeves but according to research by Jennifer Mather octopus also have “at least three distinct personality types.”
“Behavioral Sophisticates”? Black Tie and Top Hat?
“Simplicity is the ultimate sophistication” – Leonardo da Vinci
Neuroscientists in search of octopus braininess are sometimes baffled. Our nervous systems are arranged so differently that we often have trouble relating. How did the octopus (and their Coleoid cephalopod kin) develop such a treasure-chest of sophisticated behaviors, personalities even?
To uncover the origins of their “behavioral sophistication,” neuroscientists Rosenthal and Eisenberg at Tel Aviv University delved deep into the kaleidoscope of RNAs underlying the octopus’ street smarts and quick-change wardrobes.
RNA-editing in the octopus, they discovered, occurs both in the “coding RNAs” responsible for reading the genetic message directly from DNA, and the 97% of RNAs designated as “non-coding RNAs” (mostly transfer RNAs – tRNAs) that transfer messages from messenger RNAs (that copy messages directly off genes) to produce functional proteins, body parts, and complete metabolic pathways.
Ninety-three of the 109 different RNA modifications that have been identified occur in the 50 different transfer-RNAs (tRNA) that escort specific amino acids to ribosomes, where chains of amino acids are strung together to form proteins.
At least one-quarter of RNAs carry these RNA-edits, slight modifications called tags. Just as the epigenetic methyl-attachments to DNA serve to carry behavioral patterns like alcoholism, schizophrenia, or over-eating for several generations, and can be re-edited at any time – so too with RNA-edits. They’re reversible.
Like DNA-edits, RNA modifications are triggered by stress and, most likely, any critical learning situation. RNA-edits can change protein products manufactured in ribosomes for a time, for a lifetime, or for generations. Like epigenetic tags, these epitranscriptomic tags come and go in direct response to our perceptions, what we think, what we believe. Both mechanisms serve to make brain cells, pathways, and systems highly malleable.
A ribosome bound to messenger RNA (mRNA) becomes a complex that is formed during protein synthesis.
Getting a Grip on “Epitranscriptomics” – The “Neuronal Hypermutation” or “Long-term Potentiation” of RNA and DNA modifications?
“Now and in the future, no one will think of RNA without thinking ‘How is it modified?’” – Chris Mason, Weill Cornell Medical College
From what we know so far, about RNA-editing, DNA-editing, epigenetic modifications, and random mutations, each of the 100 billion neurons in the brain is acquiring new molecular characteristics every millisecond. Neuronal connections are constantly changing with our situations, our needs, and the strength of our beliefs. If we gain “experience-dependent plasticities” before becoming parents, we will pass on these acquired traits to our offspring. In this way, evolution is self-determined toward what we each think works best.
In the human immune system, long-lasting adaptations to specific pathogens that result in immunity is called “somatic hypermutation.” Similarly, trillions and trillions of what we might call “neuronal hypermutations” occur in the brain. In the VL/MSF system of the octopus, like its mammalian counterpart the hippocampus, use of repetition along neural pathways achieves long-term potentiation (LTP) that locks in memories of behaviors along those pathways and shifts memories from short to long-term. The more any trait get used over a lifetime, the more it becomes amplified generation to generation. Molecularly, the more that any one modifications of DNA or RNA is used, the more this edit becomes “long-term potentiated.”
Over generations, the most advantageous modifications attached to DNA and RNA develop as activators, promoters, repressors, and silencers along genes. Meanwhile, in addition to swarms of epigenetic tags and markers attached to huge histone proteins and DNA itself, battalions of RNA-edits are also busy in ribosomes, modifying the genetic message even further. As particular stretches of DNA develop cohesion and tenure and their functions become known to us, we call them “genes.”
Like epigenetic modifications, RNA-editing provides us a molecular turnpike for getting smarter while we live, then passing it on. Nothing new under the sun, the theory goes back to antiquity, to Aristotle and Hippocrates among many others. Jean Baptiste-Lamarck published his Theory of Acquired Characteristics of evolutionary adaptation in 1809, the year Charles Darwin was born. But it took the new science of “epitranscriptomics,” and the colorfully clever octopus to show us exactly how an assortment of beneficial characteristics could be latched onto, locked into place, but still remain flexible and open to change. RNA and DNA-editing allows the octopus, and mankind too, to amplify our genetic powers, get smarter with age and experience, acquire those sets of characteristics we choose, and gift what we’ve learned to the next generation. That’s not natural selection; RNA-editing results from our own selections, how we each choose to think, believe, and act accordingly.