Octopuses in shallow waters, such as the common octopus, typically possess larger brains.
Image Credit: Shutterstock
Research suggests that the large brains of octopuses are influenced more by environmental conditions than by social interactions.
It is widely accepted that larger mammalian brains correlate with social behavior, a theory known as the social brain hypothesis. The premise is that the more social connections a species has, the larger their brains must be to handle those interactions. This trend is evident among primates, dolphins, and camelids.
In contrast, cephalopods—like octopuses, cuttlefish, and nautiluses—exhibit significant intelligence despite mostly living solitary lives, with limited parental care and minimal social learning.
To delve deeper into the reasons behind the substantial brain size of these creatures, Michael Muthukrishna and researchers from the London School of Economics analyzed data from 79 cephalopod species with available brain information. They quantified brain size based on the total volume of an animal’s central nervous system, considering that octopuses actually possess nine brains: one central brain and semi-independent brains in each of their eight arms.
“This species is a stark contrast to humans, showcasing unique appendages and behaviors,” Muthukrishna notes.
The findings revealed no direct correlation between brain size and sociability. However, they did uncover that cephalopods generally have larger brains when inhabiting shallow waters, where they encounter a wide array of objects to manipulate and use as tools, along with rich calorie availability. Conversely, species dwelling in featureless deep-sea environments tend to have smaller brains.
“The correlation is quite strong,” Muthukrishna states, “but it’s imperative to approach these findings cautiously,” as only about 10 percent of the existing 800 cephalopod species have brain data accessible.
“The absence of a social brain effect in octopuses is intriguing yet expected,” explains Robin Dunbar from Oxford University, who proposed the social brain hypothesis around three decades ago. He argues that because octopuses do not inhabit cohesive social groups, their brains lack the necessity to manage complex social dynamics.
Professor Paul Katz from the University of Massachusetts articulates the possibility that evolution may have led to smaller brain sizes each time cephalopods adapted to deep-sea environments. “It’s reminiscent of species dimensions reducing on isolated islands; the same could apply to species in the deep ocean,” he mentions.
Muthukrishna’s previous research proposed that brain size not only predicts the extent of social and cultural behaviors but also reflects ecological factors such as prey diversity. Thus, the parallel patterns between cephalopods, having diverged from vertebrates over 500 million years ago, and humans bolster the cultural brain hypothesis. According to Muthukrishna and colleagues, this hypothesis illustrates how ecological pressures and information acquisition lead to the development of larger, more complex brains.
“It’s not solely about social instincts when it comes to large brains,” Muthukrishna asserts.
“I wholeheartedly agree that exploring why humans possess large brains must be informed by our understanding of current species. However, unraveling the evolutionary history of large brains, particularly with cephalopods, is challenging, especially given the radically different predator-prey dynamics when their brains began evolving,” Katz explains.
Dunbar emphasizes that octopuses may require substantial brainpower for their independent-use of eight arms. “Understanding an octopus’s brain is complex due to its unique structure, but a significant part of its brain’s function is to manage its intricate body mechanics necessary for survival,” he states.
Furthermore, Dunbar notes that it is logical for larger brains to evolve in environments abundant in calories. “You can’t increase brain size without addressing energy consumption. Once you have a more substantial brain, its applications become vast, which is why humans can engage in writing, reading, and complex mathematics—skills not inherently present within our evolutionary contexts.”
As quantum computing technology evolves, it becomes crucial to pinpoint challenges that can be tackled more efficiently than with classical computers. Interestingly, many significant tasks that quantum advocates are pursuing may not necessitate quantum computing at all.
The focal point of this discussion is a molecule called FeMoco, essential for life on Earth due to its role in nitrogen fixation. This process enables microorganisms to convert atmospheric nitrogen into ammonia, making it biologically available for other organisms. The mechanisms of FeMoco are intricate and not completely understood, but unraveling this could greatly diminish energy usage in fertilizer production and enhance crop yields.
Understanding FeMoco involves determining its lowest energy state, or “ground state” energy, which necessitates examining several electron behaviors. Electrons, being quantum particles, exhibit wave-like properties and occupy distinct regions known as orbits. This complexity has historically made it challenging for classical computers to calculate the various properties of FeMoco accurately.
While approximation methods have shown some success, their energy estimates have been constrained in accuracy. Conversely, rigorous mathematical analyses have demonstrated that quantum computers, utilizing a fundamentally different encoding of complexity, can resolve problems without relying on approximations, exemplifying what is known as ‘quantum advantage.’
Now, researchers such as Garnet Kin Rick Chan from the California Institute of Technology have unveiled a conventional calculation method capable of achieving comparable accuracy to quantum calculations. A pivotal metric in this discussion is “chemical precision,” which signifies the minimum accuracy required to yield reliable predictions in chemical processes. Based on their findings, Chan and colleagues assert that standard supercomputers can compute FeMoco’s ground state energy with the necessary precision.
FeMoco embodies various quantum states, each with distinct energy levels, forming a structure similar to a ladder with the ground state at the base. To streamline the process for classical algorithms to reach this lowest level, researchers concentrated on the states located on adjacent rungs and inferred their implications for what may exist one or two steps below. Insights into the symmetries of the electrons’ quantum states offered valuable context.
This simplification allowed researchers to use classical algorithms to establish an upper limit on FeMoco’s ground state energy and subsequently extrapolate it to a value with an uncertainty consistent with chemical accuracy. Essentially, the computed lowest energy state must be precise enough for future research applications.
Furthermore, researchers estimate that supercomputing methods could outperform quantum techniques, allowing classical calculations that would typically take eight hours to be completed in under a minute. This assumption relies on ideal supercomputer performance.
However, does this discovery mean you’ll instantly understand FeMoco and enhance agricultural practices? Not entirely. Numerous questions remain unanswered, such as which molecular components interact most effectively with nitrogen and what intermediate molecules are produced in the nitrogen fixation process.
“While this study does not extensively detail the FeMoco system’s capabilities, it further elevates the benchmark for quantum methodologies as a model to illustrate quantum benefits,” explains David Reichman from Columbia University in New York.
Dominic Berry, a professor at Macquarie University in Sydney, Australia, highlights that although their team’s research demonstrates that classical computers can approach the FeMoco dilemma, it only does so through approximations, while quantum methods promise complete problem resolution.
“This raises questions about the rationale for utilizing quantum computers for such challenges; however, for more intricate systems, we anticipate that the computational time for classical approaches will escalate much faster than quantum algorithms,” he states.
Another hurdle is that quantum computing technology is still evolving. Existing quantum devices are currently too limited and error-prone for tackling problems like determining FeMoco’s ground state energy. Yet, a new generation of fault-tolerant quantum computers, capable of self-correction, is on the horizon. From a practical standpoint, Berry suggests that quantum computing may still represent the optimal approach to deciphering FeMoco and related molecules. “Quantum computing will eventually facilitate more general solutions to these systems and enable routine computations once fault-tolerant quantum devices become widely available.”
Jelly-like midsections, thunderous thighs, and muffin tops — derogatory terms abound for the parts of ourselves we feel insecure about. Many cultures view fat as, at best, mere insulation or an obstacle to be eliminated. However, it’s time to shift this perspective.
While excessive body fat is linked to various health issues such as cancer, heart disease, and type 2 diabetes, it’s noteworthy that not all individuals with obesity experience these adverse effects. This indicates a more complex scenario at play. Our comprehensive cover story reveals that fat is far from being a passive entity. Instead, it functions as a vital, dynamic organ that collaborates with the brain and bones to support overall health.
This essential reevaluation of fat allows us to perceive obesity as a form of organ dysfunction rather than a moral failing. Such a change in perspective can shift the dialogue from stigmatization and fat-shaming to developing effective treatments for obesity. Current research is exploring innovative methods to “reprogram” dysfunctional fat cells to enhance health and even transform “unhealthy” obesity into less harmful variations.
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Fat is a crucial and vibrant part of the body, functioning as an organ that helps maintain our well-being. “
Encouragingly, this transformative approach does not necessitate drastic weight loss. Many advantages of contemporary weight loss medications seem to arise from enhancing the function and distribution of fat rather than merely promoting weight reduction.
Realizing this transformation could revolutionize not only health outcomes but also perceptions of what constitutes a healthy body shape. Yet, the phenomenal success of GLP-1 medications poses a risk of undermining the fat-positive movement and re-igniting outdated moral assessments regarding body size and self-discipline.
However, if fat can indeed be reprogrammed, more individuals may lead longer, healthier lives without the burden of self-consciousness about their size. Understanding the biology of fat and its interactions with the body is the first step towards this goal.
You may have heard from biohacking podcasters, flashy social media ads, nutrition experts, or radiant influencers that effectively managing your blood sugar is crucial for maintaining good health.
Blood sugar management is no longer solely a diabetic concern; it’s now heralded as essential for achieving an ideal diet, endless energy, and decreased inflammation.
It’s no wonder that online searches for “blood sugar” have surged by over 30% in the last five years, leading to a booming global market for continuous blood glucose monitors, which are expected to grow tenfold within the next decade.
Yet, amidst all this excitement, there’s a crucial message that many doctors want to convey: Most people don’t need to worry about their blood sugar levels at all. Health proponents often misinterpret this aspect.
As Dr. Nicola Guess, a clinical and academic nutritionist at the University of Oxford, puts it: “These individuals are misinformed.”
Don’t Fear the Roller Coasters
You’ve likely learned to be wary of the “peaks and troughs” in blood sugar levels—but what does that actually entail?
Picture consuming a slice of soft, airy white bread. When you digest carbohydrates, they break down into glucose, a simple sugar that enters your bloodstream.
In a healthy metabolism, your body responds by releasing insulin—a hormone that facilitates glucose transport from the blood into cells for energy. When insulin functions properly, blood sugar levels begin to decline.
As white bread is a refined carbohydrate, it converts to glucose rapidly, causing a swift spike in blood sugar levels followed by an equally quick insulin response to bring it back down.
The outcome? A notable blood sugar peak accompanied by a swift drop.
A slice of white bread can spike your blood sugar more quickly than sugar – Image credit: Getty Images
At first glance, this may sound concerning. Health influencers often warn that such blood sugar fluctuations can lead to inflammation, fatigue, cravings, and, in the long run, decreased metabolic health.
This leads to recommendations against foods that trigger rapid blood sugar changes, including white bread, pasta, white rice, potatoes, cookies, cakes, and pastries.
Instead, they advocate for low-glycemic foods like vegetables, legumes, meats, fish, and healthy fats, believed to maintain stable blood sugar levels.
While this advice holds some truth—eating protein, fiber, and fat alongside carbohydrates can moderate your blood sugar response—it’s important to reconsider the bread scenario.
Applying a generous layer of butter can slow glucose absorption, thereby controlling the blood sugar rise.
Switching to whole wheat bread increases dietary fiber, making it denser. Adding some oily peanut butter can further balance the fat and protein intake.
However, for good health, it’s not necessary to meticulously monitor the balance of fat, protein, carbohydrates, and fiber in every meal. Despite common fears, most fluctuations in blood sugar levels are normal and not something to stress over.
“Blood sugar levels should rise after consuming a carb-heavy meal. This is a standard physiological reaction,” explains Sarah Berry, Professor of Nutritional Science at King’s College London and Chief Scientist at the nutrition company ZOE.
“Blood sugar levels fluctuate, but our bodies are adept at managing this.”
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Peaks and Valleys Are Normal
One of the most enduring but misleading beliefs about blood sugar is that daily fluctuations lead to harmful inflammation.
You may have encountered a TikTok video showcasing a blood sugar monitor graph or read a caption under a photo of avocado toast promising an “anti-inflammatory” blood sugar hack.
However, inflammation isn’t inherently negative.
“Postprandial glucose fluctuations stimulate inflammation, as it’s a natural response to eating,” asserts Dr. Guess.
She clarifies that our immune systems get a small boost with every meal to defend against potential threats like bacteria and pathogens.
This mild, short-lived inflammation is not only typical but often beneficial.
“The issue arises when blood sugar levels soar and then plummet,” Berry states. “If this pattern occurs repeatedly over time, it can heighten the risk of chronic diseases.”
Individuals without diabetes are tracking their blood sugar levels – Image courtesy of Getty Images
In essence, a consistently high intake of refined carbohydrates and sugary foods can result in frequent blood sugar spikes, increasing your risk of developing type 2 diabetes and other metabolic disorders over time.
Nonetheless, for most individuals, occasional peaks and dips in blood sugar after meals are completely normal and harmless.
“Moderate spikes and dips in blood sugar are not detrimental,” Berry asserts.
The Afternoon Slump Mystery
You’ve likely heard that blood sugar fluctuations contribute to energy variations, and that peaks and troughs are responsible for your mid-afternoon slump. While there’s some truth to this, scientists still understand only part of the puzzle.
Though the science in this domain remains relatively nascent, recent research, including studies led by Berry, suggests that some individuals may feel fatigued and anxious when their blood sugar levels dip. However, blood sugar might be just one element contributing to this fatigue.
Factors like sleep quality, stress levels, and individual biological differences might equally or more significantly influence energy levels.
“There’s much we don’t know,” admits Guess. “Understanding how people feel is challenging to measure objectively.”
Afternoon slumps aren’t solely due to blood sugar levels; lack of sleep, stress, and your body’s circadian rhythms all contribute – Image credit: Getty Images
While the precise cause of fatigue and sudden energy changes remains unclear, a slight drop in blood sugar levels is typically not hazardous, particularly for those without diabetes.
An afternoon slump doesn’t pose a life-threatening risk nor will it likely affect your long-term health.
This is because the body doesn’t rely exclusively on glucose for energy; it operates on multiple fuel types. If humans were vehicles, we would be hybrids capable of utilizing different energy sources to function efficiently.
“Glucose serves as gasoline; it’s just one type of energy source for the body,” explains Guess. “Our bodies can alternate between using stored fat for energy and energy derived from food intake.”
A temporary drop in blood sugar might make you feel slightly unwell, but it doesn’t imply you’re running on empty; your body simply adapts and taps into other energy reserves.
It’s not on the brink of failure; it’s merely switching fuel sources.
No Blood Sugar Hacks Needed
You might have come across tips, tricks, and hacks designed to prevent those annoying peaks and troughs in blood sugar levels (which are usually benign).
For instance, there are suggestions to sprinkle cheese on grapes, dip apple slices in peanut butter, and start meals with vegetables to moderate your blood sugar response.
These hacks can be beneficial for individuals who are prediabetic, diabetic, or insulin resistant. As we’ve explored, including fat, protein, and fiber with your carbohydrates can help stabilize blood sugar responses.
However, for the majority of us, Guess asserts that these tips are largely unnecessary.
Blood sugar hacks may be trending, but for most people, they’re unnecessary – Image courtesy of Alamy
Even for individuals facing metabolic issues, adding extra fats can lead to unnecessary caloric intake, according to her.
“Weight gain is the primary contributor to insulin resistance, prediabetes, and type 2 diabetes; the solution for all these conditions is weight loss,” she clarifies. “Adding fat to carbohydrates only obstructs weight loss.”
Berry underscored that the route to better blood sugar levels isn’t through simple tricks but a balanced diet incorporating protein, fat, and fiber.
Blood Sugar Monitor Concerns
Some individuals amplify their blood sugar apprehensions. In recent times, it has become more common for non-diabetics to utilize continuous glucose monitors (CGMs). Originally deemed medical devices for type 1 diabetes patients, these sensors attach to the arm and track blood sugar levels in real time.
Dr. David Unwin, a general practitioner with a focus on nutrition, mentions that CGMs can be advantageous for patients with diabetes, prediabetes, or excessive junk food consumption, as they provide “like having a police officer on your arm,” offering instant feedback about hidden sugars in food.
Many CGM providers suggest wearing the device briefly, such as for two weeks, to observe how blood sugar levels react to various meals.
However, Berry argues that constant CGM use is “neither necessary nor beneficial for healthy individuals.” Guess cautions that it could lead to “profound anxiety and negative impacts on mental health” surrounding food choices.
In extreme cases, this anxiety can spiral into dangerously obsessive eating behaviors, like orthorexia. Orthorexia is an eating disorder characterized by an obsession with perfect health.
While evidence suggesting CGM use can escalate to orthorexia is scarce, Unwin notes that those who monitored their blood sugar levels did not exhibit signs of developing eating disorders.
Still, any eating behavior can evolve into an obsession, and relying on blood sugar levels as a measure of food quality is a “false flag,” according to Guess.
Over 2 million people in the United States use continuous blood glucose monitors – Image courtesy of Getty Images
Berry added: “Some may opt for cookies over bananas after learning that bananas spike blood sugar levels more than cookies. Clearly, that’s absurd.”
Similarly, orange juice can cause a notable increase in blood sugar levels, whereas sodas with artificial sweeteners may not. However, while orange juice is a source of vitamin C and other nutrients, soda often contains artificial additives that provide minimal to no nutritional value.
Likewise, lard impacts blood sugar levels minimally, yet as a saturated fat, it can adversely affect heart health.
Ultimately, Berry asserts that blood sugar levels represent only “one piece of the puzzle,” and dietary guidance should consider aspects like cholesterol, blood pressure, weight, and gut health—not solely blood sugar.
When addressing significant health threats, particularly heart disease, high blood pressure and cholesterol are “far more critical than glucose,” Guess emphasizes.
In contrast, “the influence of food on blood sugar levels is likely to have a minimal effect on overall health,” she adds.
In essence, refrain from fixating too much on blood sugar levels; even an awareness of them might not lead to substantial improvements. And if that focus dictates your meal choices, you may be overlooking the broader picture.
“As a nutritional scientist, I don’t want to overshadow the essence of food: It is meant to be enjoyed!” Berry concludes.
The Perseverance rover from NASA has uncovered unusual leopard spot-like formations on rocks, suggesting potential evidence of ancient microbial life. Scientists consider this discovery to be the strongest and most definitive indication that life may have existed on Mars.
Erratic Weather Patterns
Sudden shifts in weather can lead to severe repercussions. Weather trends are swinging between extremes more rapidly and with greater frequency than ever before.
Experiencing Lucid Dreams
Imagine being able to slip into a lucid dream every night, where everything feels vivid and you have complete control—even the ability to fly. While there are techniques to master this skill yourself, researchers are also innovating technology that could unleash tremendous new experiences.
Breathing Techniques for Better Health
Breathing is often an automatic function, but consciously practicing deep breathing can offer numerous health benefits. Here’s what you need to know to enhance your well-being from the comfort of your couch (or bed!).
Additionally
A Key Tool in Combating Depression: Depression is a common affliction, and researchers are continually exploring quicker and more cost-effective treatment methods. Could the nutritional supplements favored by bodybuilders and athletes hold the key?
Artificial Intelligence: How much further can AI evolve, or has it already reached its peak?
Q&A: I have addressed your queries. This month features a thrilling topic: Are psychopaths born or made? What’s the most chilling experiment we’ve conducted? Which organs can we live without? Can animals detect death? What is the foulest smell in existence? Can you get a phone signal on the moon? Should I store my car keys in a Faraday box? Am I alexithymic? Should I start using rosemary scents? Plus more…
Issue 425 Releases on Tuesday, October 14, 2025
Don’t forget that BBC Science Focus is also accessible on all major digital platforms. You can find a version available for Android, on Kindle Fire and Kindle e-readers, as well as the iOS app for iPads and iPhones.
Two weeks before the pandemic lockdown in March 2020, I flew to Tucson, Arizona, and knocked on the door of a suburban ranch-style home. I was there to visit Stuart Hameroff. He is an anesthesiologist and co-inventor with Nobel Prize-winning physicist Roger Penrose of a radical proposal for how conscious experience arises: that the origins of conscious experience lie in quantum phenomena in the brain.
Such ideas, in one form or another, have existed on the fringes of mainstream consciousness research for decades. There is no solid experimental evidence that quantum effects occur in the brain, as critics claim, and aside from a clear idea of how quantum effects produce consciousness, they come in from the cold. Not that it was. “It was very popular to bash us,” Hameroff told me.
But after a week of questioning him about the concept, I realized that at least his version of quantum consciousness is widely misunderstood. Partly, I think it’s Hameroff’s fault. He gives the impression of a single package. In fact, his ideas are a series of independent proposals, each forcing us to confront important questions about the relationship between fundamental physics, biology, and the indescribable thing called consciousness.
Furthermore, during my visit I saw several experiments that Hameroff had proposed come to fruition, and it became clear that his ideas could be applied to experimental research. Researchers have now provided preliminary evidence suggesting that fragile quantum states can persist in the brain and that anesthetics can influence those states.
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