Transcription
Concealed among the vibrant diversity of life on our planet, there are creatures that operate as part of a larger unified whole. They surrender their minds, their desires, and their individuality to the collective to the point where seemingly indisputable boundaries of life are blurred. From a million minds woven into a single will, what emerges is a higher order of being, one that serves a greater purpose than any of its parts could hope to achieve alone. What emerges is a super organism?
But how is that possible? We've always been told that evolution relies on survival of the fittest. So, how can evolution maintain groups that are so selfless, that have given up their ability to reproduce and pass on their genes? What kinds of systems start to emerge when you reach a state of ultimate collaboration? I'm James Stewart and you're watching Astramm Earth. Join me in this video as we delve into the world of super organisms and why some animal groups seem to fit this description. This is an idea we've been talking about for over a hundred years. One that appears to defy the laws of evolution and push the boundaries of the life we thought we knew. But what actually is a super organism? What are its features? And how on earth did this evolve?
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Although it sounds very new in space age, the term superorganism has been around for a while. It was first coined by William Morton Wheeler in 1911, who used it to describe how ant colonies seem to act not as individuals, but as a single unit. If you were to organize the components of life on a staircase, then you'd probably put simple building blocks like amino acids at the bottom, followed by complex molecules like DNA one step up, followed by organels, cells, organs, organ systems, and finally complex organisms like us. At that point, you'd be at the top of the staircase, right? Well, no. If we accept the idea of the superorganism, then there'd be a whole step above us at a higher level of biological organization. See, a superorganism is where multiple organisms come together to act like a single larger organism. So, you can think of each individual as a cell and the group as a body. An organism made of organisms. It's quite meta.
It's hard to see how this could have evolved, but scientists have theorized that superorganisms are an extreme form of cooperative group. We see lots of examples of cooperative groups in nature. Animals like whales and elephants like to stick together in a pod or a herd where they look after each other's young and defend each other against outside threats. Even bacteria can cooperate. For example, some species secrete helpful chemical compounds like ramnolippids which act as a kind of bacterial lubricant to help other individuals spread further across a surface. But unlike these groups, scientists believe the kinds of cooperative group that went on to form super organisms underwent a major evolutionary transition. Using our analogy from earlier, they took a step up on the staircase of biological organization.
So, how did this step up change things? A trait that many superorganisms have is something we call eusociality. This is a complex social system with four characteristics. The first is that adults live in groups. And as we mentioned earlier, this is true for a lot of other animals. The second involves juveniles caring for offspring that are not their own. And again, several non-eusocial animals do this, too. The third is that generations must overlap so that newborns can be raised whilst their mother is still alive. The fourth one is where things get more specific and many scientists believe this is the key feature of a eusocial society. There must be a reproductive division of labor where a chosen few individuals are allowed to reproduce and populate the colony whilst the rest are either sterile and can't reproduce at all or they get punished if they do.
The term fitness describes your ability to survive and reproduce and this is what every living thing on Earth is trying to maximize. So scientists were especially shocked by the idea of selective reproduction at first, considering that the famous motto survival of the fittest had always been used to describe the fittest individuals, not the fittest groups. How do we explain the species willingness to throw away their hopes of having their own kids and help their parents to reproduce instead? Well, the key point is that fitness can come in a direct or an indirect form. It turns out for many of these eusocial groups, the indirect fitness they get from helping their siblings is greater than any direct fitness they would get from having their own kids. William Hamilton was the biologist to champion this idea, expanding on Darwin's natural selection into the theory of kin selection.
There are many ways that this theory is interpreted across the animal kingdom. For example, many of the eusocial insects are what we call haplo-diploid where males are born from unfertilized eggs. That's the haplo part and have half the genetic material of females who are born from fertilized eggs diploid. Applying some maths, we see that this system results in female workers being related to each other by 75% instead of the usual 50%. That's a higher relatedness than they would share with any offspring they may produce. So, you can see why it makes more sense to help your mother queen produce more of your super sisters than betray the colony and have your own kids. Not all eusocial animals are haplo-diploid though. For some, it might just be that the environment is really tough to survive in. So, you're better off sticking together as a group and helping to raise your siblings rather than trying to have offspring of your own.
This arrangement of dividing labor often takes the form of the caste system, which spans beyond just reproduction and sorts individuals into different specialized jobs within the colony. The job you go into is determined by a mix of nature and nurture. As I mentioned, if you're born a sterile worker, then there's no chance that you'll become queen. But other roles are more flexible and depend on environmental factors like your diet, hormones, and pheromones. The caste system ties in really well with the superorganism concept. In your body, you have cells that are reserved for reproduction only, just like the queens for many of these eusocial species. You also have cells that are specialized for other jobs like nerve cells to conduct electrical signals, fat cells for energy stores, and red blood cells to carry oxygen and carbon dioxide. Well, the amazing thing about eusocial groups is that lots of them are specialized for other jobs, too. But instead of specialized cells, you have specialized individuals.
With that, let's take a look at some of the most extreme jobs on offer in eusocial colonies. It's thought that all ants exhibit at least some level of eusociality, mounting to nearly 14,000 species. So, it's no surprise that many of the weirdest and most wonderful castes can be found in ant colonies. In the barren deserts of Australia, the flowers of the mulga tree only bloom after periods of rainfall which are few and far between. However, Camponotus inflatus or the honeypot ant has created a nifty solution to this problem in the form of a living larder within their underground colonies. They look like little golden beads, but these specialized workers are designed so that in the event of a food shortage, the other workers can just stroke their antenna and be rewarded with a regurgitated meal of stored honey. Yum. These ants are so jam-packed with honey that their abdomens are the size of a small grape. And even the local indigenous Australians value them as a sweet delicacy. Another species of this ant found in Mexico even seems to organize its larder by honey type. Much like an insect wine seller, ants swollen with darker amber colored honey are grouped together and kept further underground in the colony whilst lighter and more cleared honey pots are kept separate. Scientists found that the darker honey stores contained more sugar whilst lighter ants store more water, suggesting that this species likes to keep a mix of both depending on which resources run low. A good strategy when you live in dry, unpredictable environments like this one. Sounds like a pretty good job, right? Just stuff yourself full of honey and hang upside down the living larder until there's a food shortage. How do I apply? But this is a key example of just how specialized these eusocial colonies can become. If you weren't living in a group, this would be a terrible strategy for survival. You'd be a major target for predators with no real chance of defending yourself or running away. But with the protection of hundreds, if not thousands of your sisters against any threats, you can happily succumb to your role of honeypot with the knowledge that the other important jobs are being taken care of.
Moving on from the ants storing food to the ants that are producing it. It might be hard to believe, but we're not the only species interested in agriculture. And we weren't even the first to do it. The attini ants are a group found in the South American rainforest and have been farming fungus on an industrial scale for up to 60 million years. It probably began when the ancestors of this group started eating fungus, setting an irreversible evolutionary change in motion to the point where nowadays the ants are completely dependent on the fungus for protein. And the fungi can only survive with the help of the ants. But how does it work? Well, it's the job of the attini ant farmers to cultivate their fungi in subterranean gardens. But instead of photosynthesis, it's decomposition that produces all the carbohydrates, proteins, and lipids they need for food. When a new queen leaves her natal colony to go and start a new colony of her own, she takes a small pellet from the fungal garden and stores it in a special pocket in her mouth. This pellet is the beginning of the fungal garden in her new colony. And many scientists believe that this method of fungal subsampling is the ant's equivalent of artificial selection in the same way that humans have selected crops over hundreds of years to maximize yield and efficiency.
We can't forget about the queens, of course. Like their workers, they've undergone some pretty crazy adaptations in order to rule. And this is particularly true of the termites. Once a colony is up and running, a termite queen's abdomen can swell up to 4 inches long, while her head remains the same size. She's so large she relies completely on her workers to feed her, groom her, and even carry her eggs away to be hatched. And there's a lot of eggs to carry away. Some estimate that a termite queen lays around 30,000 eggs per day. Despite this extraordinary reproductive output, termite queens can live for around 15 years, a hundred times longer than any of her workers. This is pretty amazing considering that reproduction usually shortens your lifespan. But scientists think this is possible due to the low extrinsic mortality experienced by queens. They're kept deep underground in the royal chamber away from predators and disease.
So, after highlighting some of the jobs you can do in a eusocial insect colony, we're beginning to get our first hints of why these colonies are described as super organisms. We've seen ants acting as energy stores like fat cells in our bodies, food producers like those cells and enzymes that generate nutrients for us, and huge queens reserved for reproduction like our sperm and eggs. But what if I told you it's not just specialized cells we see replicated at a superorganism level but entire systems.
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Professor Thomas Pradeu argued that the immune system is the defining feature of an organism. By this logic, if we see evidence of an immune system that spans beyond the boundaries of single individuals in a colony, then this would provide strong support for the idea of that colony as a superorganism. And in fact, we do see this in several eusocial insect groups, including ants, termites, beetles, and the group we'll be focusing on here, honeybees. Social immunity describes any collective immune defense against parasites and it's been studied extensively in honeybees. These defenses may be prophylactic, meaning that they've been put in place before exposure to disease or activated in the event of infection, but they've all evolved for the purpose of disease avoidance, resistance, and tolerance. Just like our human immune systems, there are plenty of reasons why you'd want an extra level of defense for your colony. And it's no surprise that living in a group means that it's easier for diseases to spread. Just think back to COVID. It's thought that individual honeybees have just a third of the number of immune genes as fruit flies despite having similar immune systems. Now, that's because the social immune responses employed by honeybees are so successful, they can subsidize the immunity of each individual honeybee. With this in mind, let's explore how the honeybees have outsourced their immunity to the colony level.
We mentioned those defenses that are in place before the colony is exposed to disease, and most of these come under disease avoidance. As it turns out, honeybees have come up with some ingenious solutions to keep their hives disease-free, many of which are on par with our own defenses as humans. You might have heard of this component in your dietary supplements or skin care. But propolis is a major component of the honeybee defense system against disease. It's an antimicrobial substance made from plant resins, which is then combined with bee saliva and coated over the interior walls and nest entrance in a layer just half a millimeter thick. Once it's enveloped around the colony, the propolis layers help maintain stable colony conditions by waterproofing, maintaining a consistent temperature, preventing fungal decay, and reducing the microbial load of the hive. In more extreme cases, propolis can even be used to engulf bodies that enter the hive. Just look at this poor unfortunate mouse. This mouse skull was found in an apiary at the University of Minnesota, completely encased in propolis. It's thought that since the mouse was too large for the bees to remove from the hive, instead they embalmed it in a thick layer of propolis to prevent the body from decaying and spreading disease. Scientists have compared this behavior to phagocytosis in organisms since it shares the same principle of engulfing a foreign body to reduce the spread of disease and have used it in support of the superorganism theory.
Say a honeybee colony is exposed to a parasite. How do they cope then? This is where disease resistance comes into play. And honeybees have lots of behaviors up their sleeves to deal with this threat. It usually starts with something called allo-grooming. If a foraging bee has picked up some kind of parasite from the surroundings, then it will begin a special grooming dance, which encourages its hivemates to approach. The other bees set to work using their mandibles to comb the hairy parts around the base of the bee's wings where their spiracles are. This happens to be where tracheal mites are usually found, confirming that this behavior serves a disease-fighting purpose. Scientists have found this behavior is really effective, too. In a study on the western honeybee, scientists found that inhibiting the bee's ability to perform their grooming behaviors resulted in significantly higher levels of tracheal mite infestation, proving that genetic resistance alone is not enough to keep them healthy. But if the bee is unlucky and can't be cured with allo-grooming, there are other ways to reduce the disease risk to the colony. I'm sure you remember social distancing from the days of COVID with a shudder. But it turns out we weren't the only ones doing it. Honeybees also carry out social distancing from any bees that have been infected with disease, shunning them from social interaction until they become a bit of an outcast. They do this by detecting changes to the chemical composition of the cuticle, the outermost layer of the exoskeleton, which happens as a result of infection. The silent treatment isn't just reserved for the adults, either. The brood, which constitutes the larvae of future workers and queens, can be removed from the colony entirely if they're found to be infected. Scientists can test how effective this undertaking behavior is with a freeze-killed brood assay. They freeze some of the brood with liquid nitrogen, then record how long it takes the bees to remove all the dead larvae. In some of the most hygienic colonies, 100% of the dead brood are consistently removed within 48 hours. You can see why this is useful. In the event of an infection, time is of the essence. And the faster the bees can remove infected individuals, the less chance there is for disease to spread to the rest of the colony.
If a bee is really sick, then it can choose to make the ultimate sacrifice for the good of its colony. Scientists have observed sick bees committing altruistic suicide where they permanently leave the colony even though this means certain death. This seems like the ultimate betrayal of self-interest, but it's often a last resort reserved for those bees that have no hope of recovering from their illness. At the very least, they know that they're doing their bit for the colony as they fly away from home one final time.
On a less depressing note, bees have also developed ways to cope with the consequences of infection with a range of systems in place for disease tolerance. Going back to the caste system, it seems one of these systems is to give certain castes immune privilege. Though she may not collect nectar or raise the brood, the queen is the essence of the colony with the responsibility of populating the entire hive. So, it makes sense that she would need to be protected from disease as much as possible. To do this, the hive has a special and complex structure where those bees that have the most contact with the outside world and its parasites are kept furthest away from the queens and nurses for the brood. David Baracchi and Aleandro Chini explored this further by taking photos of a honeybee colony every minute for 10 hours to see how the bees moved around the comb. They then created estimates for the home range of each bee group within the hive to investigate the patterns of overlap. Not only were the forager bees kept away from the nurses and queen, but the bees were also separated by age.
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This is because older bees are more expendable with weaker individual immune systems. For those reasons, the older bees are given the riskier jobs like forager, which in turn keeps them away from the queen. This phenomenon is known as temporal polyethism. And though it's pretty unfair on the senior bees, it helps to protect the key elements of the colony from infection. So it turns out honeybees and many other eusocial insects have whole immune systems operating at the colony level providing socialized medicine so that the group can avoid, resist, and tolerate exposure to disease. For Thomas Pradeu at least, this is sufficient evidence to say that these groups are organisms in their own right.
But in case you're not convinced, let's look at how all these amazing behaviors are communicated between individuals. Another major system that is key to many organisms is cell signaling. This is the process by which complex messages about your body's health, nutrition, and activities are communicated between cells, which is vital for coordinating our responses to the world around us. Well, if there really are super organisms, then they would need to do this, too. But instead of cells communicating, it's individuals. We know that eusocial insects can't talk. So, how are they getting these messages across?
Before we leave the bees behind, we have to mention one of their most impressive displays, the honeybee waggle dance. I'm sure you want to learn the steps, so here's how it goes. When a forager bee finds an especially good flower for nectar, it rushes back to the hive to tell its friends. It proceeds to move its body in a figure of eight on the vertical combs in the hive, punctuated by a waggle run in the middle, where, like the name suggests, it waggles from side to side. This dance language was first decoded by Karl von Frisch nearly 80 years ago. And you'd be amazed at how much information is crammed into one performance. Firstly, the direction of the food source can be worked out from the angle the bee moves during the waggle run. As I mentioned, the dance floor is a vertical piece of comb. So, if you think of this like a clock, 12:00 is in the same direction as the sun. 3:00 is 90° to the sun's right and 9:00 is 90° to its left. Secondly, the follower bees can learn the distance to the food source from the duration of the waggle phase. In bee dance language, it's broadly accepted that 1 second of waggling corresponds to around 750 to 1,000 m in distance. Therefore, the longer the bee waggles, the further away the food source is. Finally, and perhaps most importantly, the bee's enthusiasm whilst it performs the dance tells you about the quality of the communicated food source. The more intense the waggling, the better the flower will be. This dance language is incredible and can serve as a backup of information for times when it's harder to source information about the environment on your own or if your own information is of poor quality.
Leaving the bees behind, sadly, we're visiting a very different eusocial group, a mammal. In fact, the naked mole rat has evolved to live in underground colonies where a queen reproduces with one of her males. Whilst around 300 male and female workers attend to her every need. Just like the eusocial insects, naked mole rat colonies have been described as super organisms and their complex communication systems are an example that proves why. Early field studies of these animals noted their extensive vocalizations in the form of peeping, chirping, and grunting sounds. It makes sense for them to be this chatty since the underground burrows of Somalia and Kenya would be dark and narrow, extending over several thousands of meters. Also, it's not like the naked mole rats have the best eyesight, so they need to rely more heavily on their other senses to communicate and ensure that the colony can function properly. Scientists have identified 25 different vocalizations in naked mole rats, all designed to communicate different messages and elicit different social behaviors. So, let's decipher the code and see what some of them mean. The most common sound a naked mole rat makes is the soft chirp. This sounds like a chick peeping. And scientists think that it's used by naked mole rats to identify themselves as they bump into other colony members in busy tunnels. The toilet call consists of a sequence of four to eight chirps and has a very specific function. It's used by a breeding individual when they're going to the toilet. We're still not sure why you need a specific call to tell everyone this, but scientists think it could be a way to signal your status since odicues are also an important part of naked mole rat society. Finally, the V trill is thought to be used mainly between queens and their breeding males and can be used to create a kind of duet between the mating pair. There are lots more sounds that we haven't been able to cover, sadly. And many of these serve unknown functions that we're only just beginning to understand. But hopefully this demonstrates how complicated naked mole rat society is and why we consider them to be super organisms. Just like the cells in our bodies, they can recognize outsiders, their leaders, and each other using calls that communicate a huge range of complex messages, even going to the L.
From a superorganism perspective, we've covered their cells, their immune systems, and their communication. But what about their minds? Could there be a higher level of consciousness that you can only unlock by renouncing your ego and losing yourself in the group? Well, maybe, but it's much harder for us to prove. Superorganisms aside, it's still an ongoing process finding proof that individual animals are conscious. You can't just ask a naked mole rat or a bee if it knows that it's alive. So, we have to use their behavior as an indicator of their mental state. Though we have evidence that some animals can recognize themselves in the mirror, sadly, none of these animals are from eusocial groups. Beyond self-awareness, it would make sense for eusocial groups to show theory of mind, which is an awareness that other individuals have different thoughts, feelings, beliefs, and desires to you. This would help you to understand others, connect with them, and develop complex emotions like empathy. All important skills for living as part of a group. This research area is fascinating, and we could easily make another video. Do let us know in the comments if you'd like to see that. But the point here is that we haven't yet proven theory of mind in an experiment for any of the animals we're talking about yet, particularly insects. So until we can fully prove self-awareness or theory of mind at the individual level, it seems unlikely that we can prove it in super organisms. It's definitely interesting to think about though and raises some fascinating questions. Are the thoughts, feelings, beliefs, and desires of individuals in these groups so aligned they possess one unified theory of mind? Would they lose their individual self-awareness as a result? Are they collectively aware that other groups will have different thoughts, feelings, beliefs, and desires to them? How would this affect their collective behavior? It's mind-bending stuff.
We've come to the end of our tour of the super organisms, and what a journey it's been. Discovering these creatures that seem to sacrifice their individuality and surrender themselves to the collective has required us to reimagine the definition of organism. Beyond the level of the individual, there is now a higher level of being, one where super societies work with seamless efficiency for the good of the colony. Their instincts so aligned you may even start to question whether they present an emergent group consciousness.
Thinking closer to home, there are some features of human societies that have led some to question, have we become a super organism? Think about it. Our incredibly advanced language, culture, and technology has allowed us to communicate complex messages across the globe and establish social norms. We can find common ground with others and use this to collaborate on complex tasks. We can self-organize into groups with allocated leaders. And we can form a social identity based on the groups we interact with the most. Many of these skills are advanced, unique to humans and would be highly conducive to functioning as a super organism. As I mentioned, the hierarchy of biological organization is built on the grouping of several units to create a higher level unit. And in the context of super organisms, scientists often refer to these events as major evolutionary transitions. So, what do you think? Have we already made that major transition as a human society, or could it be something awaiting us in the future? Let me know down below in the comments.
There's no doubt that eusocial animals have unlocked new levels of efficiency in their societies. So there may be things we can learn from these groups as we expect to face new pandemics, climate crisis, and biodiversity losses into the future. Perhaps we need to start thinking and behaving more like a super organism, relying on each other, having species-level conversations, playing to our strengths, and ultimately coming together to take coordinated unified action. The potential for learning isn't just limited to these organisms. However, with Brilliant, you can also learn every day with thousands of interactive lessons in math, science, programming, data analysis, and AI available. The reason I started making these videos in the first place was because I missed that feeling of learning new stuff. I felt as if my brain was just ticking along in my old job. I could do it with my eyes closed. There was no challenge, no stimulation. So, if you're like me and you want more for your brain, why not check out Brilliant, an awesome learning app that can build your critical thinking skills through problem-solving. While you're building a real knowledge on specific topics from the most recent research, you'll also become a better thinker as a result. Science is such a part of my life and now my job, but there's still so much I don't know. So, I've been doing scientific thinking to enhance my scientific intuition through visual interactive problem-solving that gets hands-on with key concepts so I can keep bringing you the best, most well-informed and cutting-edge content right here on the channel. To try everything Brilliant has to offer for free for a full 30 days, visit brilliant.org/astramar. Scan the QR code on screen now or click the link in the video description. You'll also get 20% off an annual premium subscription. So, what are you waiting for?