Our Biological Inheritance and the Biology of Slime Mold
5 Why slime mold is smarter than modern humans (and yeast)
Modern humans learn about plants and animals in high school biology class. Some know to add metazoans (fungi), protists, and even archaea and bacteria to the list (and maybe viruses/prions too). But the form of life modern humans should try to learn from are the slime molds (and yeast). Our K-selected homininan ancestors were smarter than yeast (but non-evolvable modern r-selected metastatic humans are not). Yeast can sporulate. Modern humans cannot.
Slime molds have no brain, yet they have persisted for over 600+ Ma (million years — last single celled common ancestor 2 billion years ago, first multicellular eukaryotes 1,700 Ma, hence the + as 1,200 Ma is likely). Collectively, modern humans have no brain. Will modern humans persist for 60 years? Will evolvable (K-selected) humans (maybe 10k on the planet now) persist for 600 years?
In recent news: Slime Mold Helps to Map the Universe’s Tendrils of Dark Matter: A single-celled organism’s pathfinding reveals connections in the universe’s vast “cosmic web.”
For more, I’ll use a video from a business, Brilliant, with included promotion, but I’m guessing their business model is to avoid making factual error (but not fake claims other than about their business).
I didn’t watch the video, but had Otter AI generate a transcript, and with sound off, I added screenshots that seemed of interest. Brilliant also has a version seemingly made for high school students, replete with sophomoric expletives.
AI Overview:
Slime molds were once classified as fungi, but are now known to be more closely related to amoebas and algae [no, Protista is waste basket for eukaryotes that are not plants, animals or fungi, no close relatedness implied, e.g. amoebas and brown kelp]:
Classification
Slime molds are classified as Protista, along with algae, and are no longer classified as fungi. [I share Lynn Margulis’ view that Protista should included only single cell eukaryotes.]
Relationship
Slime molds are not plants, animals, or fungi. They are more closely related to amoebas and certain seaweeds.
Appearance
Slime molds can look similar to fungi, but they are not firm and won’t retain their shape when poked.
Life cycle
Slime molds have a life cycle that resembles fungi, forming sporangia (clusters of spores) when conditions are unfavorable. The spores are then dispersed to new areas, where they germinate into small amoebae.
Habitat
Slime molds can be found all over the world, including deserts, high altitudes, and snowbanks [like modern humans, and while mostly terrestrial, but some are aquatic].
AI Summary:
The conversation discusses the remarkable problem-solving abilities of slime molds, which, despite being single-celled and brainless, exhibit sophisticated behaviors and intelligence. Slime molds use swarm intelligence and memory to navigate environments, optimize food sources, and solve complex problems like the shortest path between cities and the traveling salesman problem. They are classified as protists and exhibit unique life cycles, including aggregation into slugs and plasmodial forms. Researchers are exploring their potential in optimization and developing algorithms inspired by their behavior.
Outline
Slime Mold’s Unique Intelligence and Applications
Speaker 1 explains that slime molds, despite being brainless, can solve complex problems more efficiently than humans, such as optimizing transportation networks and finding the shortest path between cities.
Slime molds exhibit swarm intelligence, communication, memory, and learning, making them a subject of interest for scientists.
They are classified as protists, a category for eukaryotes that don’t fit into other kingdoms, and there are over 800 species of slime molds [modern humans have formed 195 ‘countries’].
Slime molds can be classified into two main types: cellular slime molds and plasmodial slime molds, each with unique life cycles and behaviors.
Cellular Slime Molds and Their Life Cycle
Cellular slime molds exist as single-celled organisms when food is abundant but aggregate into a single unit when food is scarce.
Aggregation begins with a single cell secreting cyclic AMP, which attracts nearby cells to form a slug.
The slug moves towards attractants like light, heat, and humidity and eventually settles, forming fruiting bodies that contain spores.
The slime mold’s life cycle involves spores being dispersed by soil invertebrates, which germinate and produce amoeba, completing the cycle.
Plasmodial Slime Molds and Their Behavior
Plasmodial slime molds are much larger, sometimes reaching 30 square meters, and are a single cell containing millions of nuclei [modern human megacities contain 10 to 40 million bipedal nuclei].
They travel over damp, decaying material and primarily eat bacteria that feed on decaying plant matter [modern humans blob about the planet extracting NNRs (non-renewable natural resouces)…].
Plasmodial slime molds use tendrils to sense their environment, releasing cyclic AMP when encountering attractants or repellents.
The slime mold’s cytoplasmic streaming and tendrils help it optimize its pathway towards or away from stimuli.
Slime Mold’s Problem-Solving Capabilities
Slime molds can solve complex problems without a brain, such as finding the shortest path in a maze.
In a 2000 study, researchers in Japan demonstrated that slime molds can find the shortest path between food sources in a maze.
Slime molds avoid previously traveled paths, showing externalized spatial memory.
Scientists have used slime molds to solve combinatorial optimization problems, such as the traveling salesman problem, which traditional computers find difficult [meanwhile, modern humans are so amazingly primitive that they still think digital watches and phones are a pretty neat idea].
Applications of Slime Mold in Optimization Problems
Slime molds can solve the traveling salesman problem in linear time, unlike traditional computers, which face exponential complexity.
Researchers have developed algorithms inspired by slime molds, such as amoeba TSP, to model their behavior and solve optimization problems more efficiently.
A 2010 study found that slime molds can create an efficient network similar to the Tokyo rail system, optimizing cost, efficiency, and robustness.
Slime molds’ ability to solve optimization problems has led to the development of a slime mold modelled computer chip, which can solve a wide range of computational tasks.
Slime Mold Computer Chip and Its Potential
The slime-mold-like computer chip, made of a network of slime mold tubes coated with a conductive substance, can [may be able to] solve optimization problems like a slime mold.
The chip can handle tasks such as optimization on graphs, computational geometry, and robot control.
The development of biological computers shows that primitive intelligence can be a powerful tool in solving complex problems.
Slime molds’ complex decision-making abilities without a brain contrast with humans’ reliance on a brain for problem-solving [and failure to solve large-scale socioeconomic-political ecosystem optimization problems].
Transcript
0:00 Human society is constantly solving problems like how to most efficiently move people resources, energy and information, problems that scientists are realizing a single celled, brainless slime mold might be able to solve better than us.
0:16 If you’ve taken a walk through the forest, you may have noticed webs of a yellow substance growing across dead trees and on piles of fallen leaves, moving at a glacial pace, this slime slowly consumes the microorganisms living on these decaying materials. And while this brainless blob may seem incredibly primitive in its structure, its behavior is another thing entirely.
0:40 This unique organism is called a slime mold, and as it traverses the forest floor in search of food, it makes decisions based on a complicated trade off between the risks its hunger level and the quality of food patches. It’s been shown to demonstrate both learning and memory, and acts in such a clever way that scientists consider it to have a unique form of primitive intelligence.
1:05 In fact, its abilities are so great that researchers are using its foraging methods to solve real world optimization problems such as the shortest path between cities and the most efficient transportation network challenges that typically require a sophisticated computer algorithm.
1:23 But the applications for slime molds don’t stop there. Scientists are even using them as one of the most essential components in a computer, and are actually building computer chips containing this slimy substance in a world that’s rushing to implement advanced artificial intelligence as the answer to our problems, slime molds show us that some of the best solutions might be hiding in the most primitive places.
1:48 What even is a slime mold? And how can this simple, brainless blob solve so many problems?
Slime molds are mysterious organisms that scientists struggle to classify in the tree of life, because they surprisingly share some of the characteristics present in animals, plants and fungi, like social animals, slime molds exhibit swarm intelligence, communication, memory and learning.
2:16 However, there is one important difference. Slime molds don’t have a brain. Like plants, slime molds have the same structural material in the cell walls of their spores, an organic compound called cellulose. But unlike plants, which famously make their own food through photosynthesis, slime molds get their nutrition from outside sources, making them heterotrophs, most often, they mistakenly get categorized as fungi, which is the kingdom that includes traditional molds like fungi, slime molds are heterotrophs and reproduced by dispersing spores.
2:51 But unlike fungi, they don’t have chitin in their cell walls. They engulf their food instead of digesting it externally. And the primary cell type during their life cycle is diploid, which contains two sets of chromosomes instead of just one, as in a haploid cell, the primary cell type found in fungi. Since they don’t quite fit in any of these kingdoms, slime molds are classified as protists, a catch all kingdom that only requires its members to be eukaryotes, a cellular organism with an enclosed nucleus.
3:22 It’s basically a category for everything we don’t really understand. There are over 800 species of slime molds that can be further classified into a few main types based on their life cycle. One type is cellular slime molds. When food is abundant, these slime molds go it alone and exist as single celled organisms. But when food is in short supply, they will aggregate into a mass and start moving as a single unit.
3:50 This is sort of like swarm intelligence we see in other animals like ants. However, these individuals aren’t just working together. They literally become one entity. Aggregation begins when a single cell becomes stressed and secretes a hormone called cyclic AMP. Nearby cells respond by moving towards the hormone. Many small individuals come together to create one giant accumulation, one that acts like a single unit, like its own brand new organism.
4:21 This aggregation is called a slug, which can be between two to four millimeters long and composed of up to 100,000 cells. It moves as one unit towards attractants such as light, heat and humidity, looking for a suitable place to settle. And once it does, the reproduction process begins, the slug flattens onto a surface, and some cells develop into two to three millimeter stalks, while cells at the top of the stalks develop into fruiting bodies that contain spores.
4:53 What’s weird here is that these are still technically individual cells, some of which had the genetic fate to turn. Into a stalk, some with the genetic fate of turning into spores, and only the ones that become spores get the opportunity to reproduce, the ones fated to become stock simply die. Spores presented in this way, are then dispersed by soil invertebrates, and in the right conditions, spores germinate, produce amoeba and thus complete the life cycle.
5:23 Slime molds like this are true evolutionary head scratchers, almost always in an organism, the multicellular stage arises from a single cell, a fertilized egg. This ensures that the cells of the organism are derived from a single genotype. All of these cells are on the same team, so to speak. They all agree on the goal of passing down their shared genotype to the next generation.
5:49 In slime molds, the multicellular stage is a combination of many unrelated genotypes. Viewing these slugs with the same lens of natural selection that we view everything else in the natural world, these different cells with different genotypes that make up the slug are not on the same team in any given slug. Selection favors the cells that take unfair advantage of the altruistic cells, so much so that the selfish types of cells should threaten the existence of any altruists.
6:19 And yet, both types of cell continue to exist. How this self sacrificial behavior continues in the face of conditions that should select for its elimination has baffled scientists for years. The other major type of slime mold belongs to the class myxogastria. These slime molds are often referred to as acellular plasmodial or true slime molds.
6:44 While cellular slime molds are difficult to see with the naked eye, a plasmodial slime mold can stretch pretty far, with some species reaching 30 square meters. And despite its sometimes massive size, it in fact, is one single cell containing millions of nuclei, and this one gigantic cell is a master shapeshifter. Plasmodiums travel over damp, decaying material, like wood and leaves.
7:11 In the search for food, they primarily eat the bacteria that feeds on the decaying plant matter, making them an important player in the decomposition process. While searching for food, they send out tendrils in all directions to sense the environment around them. These tendrils are tube like structures with a gel like outer membrane. When this vascular network encounters a stimulus, the molecule cyclic AMP is released.
7:38 This initiates cytoplasmic streaming. This is the flow of cytoplasm inside the cell driven by the movement of the cytoskeleton. The rate and frequency of the contractions changes when the tendrils encounter an attractant or a repellent. When an attractant is located, which is typically a food source, the rate increases, sending more cytoplasm into the tendril to capitalize on the nutrients and send it back throughout the body of the slime mold.
8:06 This causes the tendril to grow. The opposite happens when a repellent like sunlight is located or nutrients dry up, resulting in the tendrils retracting until they disappear completely. In this way, the slime mold moves towards or away from the source of the stimulus, eventually configuring itself into the most optimized pathway. Watching this optimization process occur, scientists realized these slime molds are capable of solving some complex problems, displaying a remarkable form of intelligence and intelligence that operates without a brain.
8:44 When scientists first brought Fisserum polycephalum to the lab, it was simply to study the way it moves. No one thought that it was capable of making choices. Never mind, choices that seemed well thought out. That is, until the year 2000 when researchers in Japan put Physarum polycephalum to the test in the form of a maze.
9:05 They chopped up a single specimen and scattered its pieces throughout a plastic maze. They then put two food sources at either end of the maze. There were four possible routes the plasmodium could take to get from the start and end points. First, the plasmodial pieces spread and reconnected to form a single organism that filled the entire maze. After four hours, the parts of the plasmodium that occupied dead ends shrank.
9:33 The remaining part of the plasmodium was then weighing its options, comparing all of the possible connections. After another four hours, it selected the shortest path between the food sources, and recently, scientists realized that the way slime mold achieves this is even more complex than they thought. As it crawls through the maze, it leaves behind a trail of slime researchers realize that the slime mold will avoid this slime trail. It.
9:59 Meaning it avoids places it’s already traveled, giving it a kind of externalized spatial memory. Since then, scientists have been discovering new applications for Physarum polycephalum. One of the most common is determining the optimized route between multiple locations. This is known as a combinatorial optimization problem, where there are many solutions, but finding the best in this case, the shortest path gets more and more difficult as more locations are added.
10:29 This type of problem often comes up in the fields of AI, Software Engineering and Applied Mathematics, and using a living organism to solve such a problem could offer some interesting insight. A popular example of this is a study published in 2010 where researchers tested the efficiency of Physarum to recreate a real world infrastructure network, the Tokyo rail system.
10:54 They hypothesized that the slime mold would have been fine tuned through evolutionary selection and therefore would be capable of making the same complex trade offs between cost, transport, efficiency and robustness as a manmade transport network, and that’s exactly what they found on a flat template of the Tokyo region.
11:13 They placed food on the 36 surrounding cities connected by the rail system, and let Physarum grow freely from the centralized Tokyo location. At first, the slime mold spread out evenly over the food sources, but soon it began to optimize its pattern, leaving only the most efficient network of interconnected nutrient transport tubes.
11:35 They discovered that Physarum created a map nearly identical to the real rail system with about the same cost, efficiency and robustness. In other words, the single celled, brainless slime mold didn’t reach for its food sources, randomly becoming satisfied as soon as it had any food. It instead behaved like a team of human engineers, editing, altering and optimizing the network, creating the most efficient network possible.
12:03 And this is far from the only optimization problem slime molds have been able to solve. The traveling salesman problem is a classic problem in mathematics where a hypothetical salesman needs to visit all the cities on a map just once before returning to his origin city. The question is, which order should he visit the cities to make the shortest trip possible?
12:25 This seemingly simple problem has a lot of real world implications. A package delivery company might want to plan the shortest route between stops to save time and fuel. A school district might want to plan the most efficient bus route to take children to and from school. This is a problem that’s surprisingly difficult to solve, and for every city or every node that gets added, it gets exponentially more complicated.
12:50 When there are just four cities, there are three possible solutions. When there are eight cities, there are 2520 possible solutions. Thus, it takes traditional computers exponentially more time to solve as they go through each solution, one by one.
13:08 But researchers discovered that slime mold can solve the problem in linear time no matter how many cities get added, because it can process information concurrently, while the activity of slime molds can help us find new solutions to common problems.
13:24 The experimental process using actual slime molds is time consuming, so scientists are instead developing algorithms that model their behavior in order to test a number of different scenarios more quickly, the researchers of the traveling salesman experiment created amoeba TSP, an algorithm inspired by the plasmodium by incorporating the real life constraints and behavior of Fissurum polycephalum.
13:50 Amoeba tsp found high quality solutions that also increased linearly with the number of nodes, and now scientists are exploring the possibility of using slime molds as a physical computing medium. In a 2018 study, researchers created a slime mold computer chip, which is made of a network of slime mold tubes coated with a conductive substance.
14:13 It reacts to real world optimization problems just like a slime mold does, and the conductor transmit the information quickly, the Physarum chip solves a wide range of computation tasks, including optimization on graphs, computational geometry and even robot control.
14:31 The dawn of these biological computers shows us that while artificial intelligence may be promising, primitive intelligence crafted by millions of years of evolution may also become a powerful tool in our toolbox.
— — — — — — — — — — — — — — — — — —
First, correct the title (The Insane Biology of Slime Molds) — there is nothing insane about slime mold biology. In comparing slime molds and modern techno-industrialized humans, one form, however, is insane (and insapient).
Modern humans view slime molds as a resource for the taking to serve human short-term self interests (the economy). Some slime molds are eatable, but lets exploit them for their problem solving abilities to help grow the economy.
After over 600 million years of learning, they do have information about how to persist on the planet, but modern humans are reality blind and deaf other than to Hominina prattle (of the last hominin standing) and short-term self interests (i.e. are insane, barking mad — randomly read posts on social media, e.g. Medium).
Slime molds have no brains, no self, no agency, no free will (but they do have a likely future), and are not different in kind from modern human mega cities other than slime molds will still be blobbing about in 50, 500, 5k, 50k, 500k, 5000k, 50000k… years.
Slime molds are protists by definition: “a protist or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade.”
Eukaryotes diversified into animals, plants, fungi, and protists around 2 billion years ago. Slime mold taxonomy includes members of the Diphoda and Amorphea groups which split 2 billion years ago, i.e. slime molds may be considered a separate and unequal non-Protist kingdom (except by modern humans), and so one of the first two kingdoms of eukarya. A possible name: Slimoldia.
Slime molds have been a superorganism for over 600+ million years. Modern humanoeba have been auto organizing into superorganisms regionally (for a time) for over 7 thousand years. We moderns, who burn our fossil fuel global candle at both ends, won’t last the night.
When renewable natural resources become scarce, slime molds sporulate (they listen to Nature, the nature of things). And modern humans? We don’t even think we’ll ever need to.
So, what? We worry?
Modern humans are 13 year olds with guns and smartphones,
so amazingly primitive that they still think zero-order
humanism is a pretty neat idea.
Slime molds are 10th-order
geniuses by comparison.