The goal of this blog is to create a list of super facts. Important facts that are true with very high certainty and yet surprising, misunderstood, or disputed by many. This blog aims to be challenging, educational, and fun, without it being clickbait. I determine veracity using evidence, data from reputable sources and longstanding scientific consensus. Prepare to be challenged (I am). Intentionally seek the truth not confirmation of your belief.
Category: Biology
Important but surprising facts relating to Biology
Super fact 139 : 2.17million species have been described but it is possible that as many as 20% of those are duplicates. However, most species are likely undiscovered.
The number of identified and named species in each taxonomic group. Since many species have not yet been described, this is a large underestimate of the total number of species in the world. Note about Taxonomic group: Scientists sort living things into groups based on how closely related they are. Each of these groups is called a taxonomic group. The groups fit inside one another, from broad to narrow. Mammals, birds and fish are broad groups. Within mammals, primates are a narrower group. And within primates, humans are just one species. Data source: International Union for Conservation of Nature Red List of Threatened species (2025). OurWorldinData.org/biodiversity | CC BY
As mentioned, a couple of million species have been named and identified. For a species to be formally described, it’s description must be published in a scientific journal or book. Considering this it is quite impressive that we’ve described millions of species, mostly insects and plants. However, according to science magazine the most likely number of species is in the range of 5 to 10 million eukaryotes. Eukaryotes are organisms consisting of complex cells with a membrane wrapped in nucleus and other internal compartments, which exclude viruses and bacteria.
This graph includes a more complete set of taxonomic groups. Data source: International Union for Conservation of Nature Red List of Threatened species (2025). OurWorldinData.org/biodiversity | CC BY
The fact that we have succeeded in describing two million species is impressive and surprising. That is a lot of work. The fact that there are likely millions of more species we haven’t found is equally surprising. There are surprisingly many species and unless you already knew this, this is surprising and perhaps mind-blowing information, and therefore a super fact.
Challenges in Defining a Species
Species is a unit of biological classification and it is the lowest taxonomic rank below genus. Species is often defined using the Biological Species Concept, which is defined as populations whose members can interbreed and produce fertile offspring, and are reproductively isolated from other groups. However, it is complicated. Asexual organisms, hybrids and ring species, and extinct species complicate things. Therefore, other ways of defining species exist.
The major ranks: domain, kingdom, phylum, class, order, family, genus, and species, applied to the red fox, Vulpes vulpes. Many classifications based on genetic analysis require more than these eight ranks, not all of which have distinct names. Annina Breen, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons.
To define a species, you can also use genetic similarity, unique ecological niches, unique common ancestors, distinct physical traits, size, shape, and structural features. In other words, species concept is not simple and defining a species requires expertise. This makes it even more impressive that we have identified and described two million species.
I should add that there are also subspecies. A subspecies is a distinct population within a species that lives in a specific geographic region and differs in physical traits from other populations of the same species, while still being able to interbreed with them. An example is the dog which is a subspecies of the gray wolf.
Ring Species
As mentioned, a common definition of species is that two animals belong to the same species if they can interbreed in nature and produce viable, fertile offspring. As I pointed out it is not always that simple. An animal A may be able to successfully interbreed with an animal B, and that animal B may be able to successfully interbreed with an animal C, but animal A and C cannot interbreed. Animal A could be said to be a different species relative to animal C, but animal B could be said to be the same species as both animal A & C using the definition above.
A great geography related example of this is ring species. In a ring species, gene flow occurs between neighboring populations of a species, but at the ends of the ring the populations don’t interbreed.
Illustration of ring species, an example of how speciation can be relative. All the circles next to each other can interbreed but at the end it no longer works. Andrew Z. Colvin, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Other Super Facts Related to Wildlife
A couple of interesting super facts related to species and wildlife are :
(70) The Wild Mammal Biomass Has Substantially Declined – click to visit
(71) The Extinction Rate is Much Higher Than the Natural Baseline Rate – click to visit
The first one is concerning the fact that we humans and our domesticated animals, cattle etc., have largely replaced wild animals and wild mammals. As the total biomass has increased the wild mammal biomass has decreased. The second super fact is about the current extinction rate being perhaps thousands of times higher than what is typical. A mass extinction event is often defined as when 75% of all species, or more, goes extinct within 2 million years. 200 years is only 0.01% of 2 million years so modern society has existed for an extremely short time. It is just a tiny blip on geological scales. So, even with an extinction rate thousands of times above normal, we haven’t gotten very far yet. Luckily, it looks like we might be turning things around, so perhaps we won’t be like the asteroid that exterminated the non-Avian dinosaurs.
Extinction of the dinosaurs when a large asteroid hits earth 66 million years ago. It was the last mass extinction event. Asset id: 2196200279 by funstarts33
Super fact 134 : The idea that people have a dominant “left brain” or “right brain” that dictates their personality is a popular myth. Brain imaging studies show that people do not have a dominant hemisphere.
Shutterstock asset id: 2483871211 by Shutterstock AI
The left and right sides of the brain do tend to specialize in different tasks. For example, language tends to be on the left, and attention more on the right. Brain images studies show that we do not have a dominant hemisphere. Both halves of the brain work together and are used equally in most activities. You can read more about the topic here, and here, or here.
Four Minute Video on Left Brain versus Right Brain
The YouTube video below is 4 minutes long, but it presents a good overview of left brain versus right brain myth.
How did the right brain versus left brain myth get started ?
That the brain is divided into a left side and a right side has been known since ancient times. In the 1860’s it was discovered that speech was based predominantly in the left hemisphere of the brain. In the 1960’s Psychobiologist Roger Sperry studied “split-brain” patients who had their corpus callosum (the nerve bundle connecting the two halves) severed to treat epilepsy. Their neuroscience research seemed to show that one side of the brain tends to be more dominant in each person. Popular culture took these findings out of context and the right brain versus left brain myth took hold.
The human brain is divided into two hemispheres–left and right. Scientists continue to explore how some cognitive functions tend to be dominated by one side or the other; that is, how they are lateralized. Purple is the Right cerebral hemisphere. Blue is the Left cerebral hemisphere. Polygon data were generated by Database Center for Life Science (DBCLS), CC BY-SA 2.1 JP <https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en>, via Wikimedia Commons. The gif is taken from this link.
Later research showed that the human brain does not favor one side over the other and that one side is not more dominant then the other, unless it is damaged. The two sides of the brain work in concert. You can read more about the topic here.
A related fascinating fact is that the human brain contains about 100 billion neurons and 100 trillion connections. That is 100 trillion parameters to use Artificial Intelligence speech. Which should be compared to the 175 billion (not trillion) parameters in ChatGPT 3.5, and one trillion in ChatGPT 4.0. Well AI neurons and connections/weights and those in the brain are not directly comparable. Another related interesting myth is that we only use 10% of our brain. We use our entire brain.
The goal of this blog is to create a list of what I call super facts. Super facts are important and true facts that nevertheless are very surprising to many, misunderstood, or disputed among the public. They are special facts that we all can learn something important from. However, I also make posts that are not super facts but feature other interesting information, such as this book review and book recommendation.
The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth by Zoë Schlanger – May 7, 2024
Below I am listing the four versions of this book. I bought the hardback version.
Hardback – Publisher : Harper (May 7, 2024), ISBN-10 : 0063073854, ISBN-13 : 978-0063073852, 304 pages, item weight : 2.31 pounds, dimensions : 6 x 0.92 x 9 inches. It costs $ 19.90 on US Amazon. Click here to order it from Amazon.com.
Paperback – Publisher : Harper Perennial (May 13, 2025), ISBN-10 : 0063073862, ISBN-13 : 978-0063073869, 304 pages, item weight : 11.2 ounces, dimensions : 5.5 x 0.75 x 8 inches. It costs $15.99 on US Amazon. Click here to order it from Amazon.com.
Kindle – Publisher : Harper (May 7, 2024), ASIN : B0CFM4SMPF, 298 pages, it costs $ 14.99on US Amazon. Click here to order it from Amazon.com.
• Audiobook – Publisher : Harper (May 7, 2024), ASIN : B0CJWQ6X99, Listening length : 10 hours and 56 minutes. Click here to order it from Amazon.com.
The front cover of The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth by Zoë Schlanger. Click on the image to go to the Amazon page for the hardback version of the book.
Amazon’s Description of the Book
NEW YORK TIMES BESTSELLER
The New Yorker’s Best Books of 2024 • TIME’s 10 Best Nonfiction Books of 2024 • New York Magazine’s 10 Best Books of the Year • Washington Post’s 50 Notable Works of Nonfiction of 2024 • Smithsonian’s 10 Best Science Books of the Year • A Best Book of the Year: Boston Globe, Scientific American,New York Public Library, Christian Science Monitor, Library Journal, and Publishers Weekly • An Amazon Best Nonfiction Book of the Year
Longlisted for the National Book Critics Circle Nonfiction Prize • Finalist for the Chautauqua Prize • Finalist for the Los Angeles Times Book Prize • Winner of the National Outdoor Book Award for Natural History
“A masterpiece of science writing.” ―Robin Wall Kimmerer, author of Braiding Sweetgrass
“Mesmerizing, world-expanding, and achingly beautiful.” ―Ed Yong, author of An Immense World
“Rich, vital, and full of surprises. Read it!” ―Elizabeth Kolbert, author of Under a White Sky and The Sixth Extinction
Award-winning Atlantic staff writer Zoë Schlanger delivers a groundbreaking work of natural history and popular science that probes the hidden world of the plant kingdom, “destabilizing not just how we see the green things of the world but also our place in the hierarchy of beings, and maybe the notion of that hierarchy itself.” (The New Yorker)
It takes tremendous biological creativity to be a plant. To survive and thrive while rooted in a single spot, plants have adapted ingenious methods of survival. In recent years, scientists have learned about their ability to communicate, recognize their kin and behave socially, hear sounds, morph their bodies to blend into their surroundings, store useful memories that inform their life cycle, and trick animals into behaving to their benefit―a fascinating display of plant behavior and sensory abilities, to name just a few remarkable talents.
The Light Eaters is a deep immersion into the drama of green life and the complexity of this wild and awe-inspiring world that challenges our very understanding of agency, consciousness, and intelligence. In this captivating exploration of plant intelligence, we see that plants, rather than imitate human intelligence, have perhaps formed a parallel system. What is intelligent life if not a vine that grows leaves to blend into the shrub on which it climbs, a flower that shapes its bloom to fit exactly the beak of its pollinator, a pea seedling that can hear water flowing and make its way toward it? Zoë Schlanger takes us across the globe, digging into her own memories and into the soil with the scientists who have spent their waking days studying these amazing entities up close.
What can we learn about life on Earth from the living things that thrive, adapt, consume, and accommodate simultaneously? More important, what do we owe these life forms once we come to understand their rich and varied abilities? Examining the latest epiphanies in botanical research, Schlanger spotlights the intellectual struggles among the researchers conceiving a wholly new view of their subject, offering a glimpse of a field in turmoil as plant scientists debate the tenets of ongoing discoveries and how insights into plant communication influence our understanding of what a plant is.
We need plants to survive. But what do they need us for―if at all? An eye-opening and informative look at the ecosystem we live in, this book challenges us to rethink the role of plants―and our own place―in the natural world, tackling the enthralling question of plant consciousness along the way.
Plant Behavior and Communication is Real. What about Plant Intelligence?
This is a very interesting book that describes the ways plants behave and communicate via chemicals, fungus, sound, electric signals and light. Many plants even exhibit memory functions and are able mimic the look of other plants from a distance. A leaf is the only thing in our known world that can manufacture sugar out of materials, light and air, that have never been alive. They can produce complex chemicals, like caffeine, that humans and animals can’t produce. If weighed, plants would amount to 80% of Earth’s living matter.
Plants can regrow virtually any amputated part. Some plants inject poisons into the ground around their roots to prevent anything else from growing nearby. Plants can recognize and protect their kin. Many plants will rearrange their leaves to avoid shading siblings. One of the points of the book is that we may have underestimated plants.
The book also discusses the possibility that plants may have a type of intelligence, perhaps even consciousness, depending on how you define it. This is a philosophical discussion. It should be noted that there was a very popular book in the 1970’s that made outlandish and pseudoscientific claims about plants. In the long run this book created a lot of skepticism towards claims within botany that seemed far-fetched despite collaborating evidence. The author laments this conservatism at the same time as she understands it.
There is a problem with getting unconventional work published in botany, at the same time the arduous peer-review process is an essential safeguard against false paths.
However, it has been established that plants do a lot of amazing things, and we are just beginning to realize the extent of plant behavior and communication. Some examples are, plants can communicate with each other even when they are too far apart to be passing information through their roots (perhaps pheromonal substances).
Plants produce electrical impulses and seem to have nodes at the tips of their roots that serve as local command centers. Plants can react to an attack of munching insects by summoning those insects’ specific predators to come and pick them up. They can perceive gravity, but we don’t know how. Primrose increases the sweetness of its nectar within three minutes if you play an audio recording of honeybee flight to it. Pea plants and many other plants grow their roots toward the sound of running water.
Other examples are, Tomatoes make thirty-five sounds per hour when drought stressed. Goldenrod can sense the volatile signals of nearby gall-forming flies and jump-start its immune system before the flies even make contact. Researchers who played tones at different frequencies to alfalfa sprouts for two hours saw that they increased the plants’ content of vitamin C. Plants can hear the caterpillars or pick up the vibrations they cause. Trichomes allow plants to sense the footsteps of moths and caterpillars.
Nasa poissoniana can store and recall information. It can remember the time intervals between bumble bee visits and anticipate the next time their pollinator was likely to arrive. Bittersweet nightshade recruit ants as bodyguards. Cornish mallow, a pink-flowered plant, will turn its leaves hours before sunrise to face the horizon in exactly the direction its expects the sun to rise. A common vine in this rainforest was capable of spontaneously morph into the shape of almost any plant it grew beside.
Plant mimicry is not that unusual. Scientists have long observed that virtually all plants are highly sensitive to touch of any kind and will change their growth accordingly. The book features several dozen more amazing examples of plant behavior, communication, sensing, and forms of memory including generational memory.
The book also delves into some other topics such as the importance of microbes for both plants and animals, including humans. Microbes influence our immune systems, our smells, and our attractiveness to mosquitos. Emerging research suggests that they may play a role in autism, depression, anxiety, and possible even who we are attracted to. The author also notes that pollution steadily filling the air appears to sabotage plants ability to send and interpret each other’s signals.
This is a book that is filled with interesting and perhaps even shocking information, and it certainly made me more interested in plants and botany. I think the book made the outlandish ideas about plant intelligence and conscience appear almost plausible. Plants are all around us and they are more interesting than I thought. The book is also well written and well organized. I should say that I did not think the first three chapters were very interesting, but it got better the further I read. I highly recommend this book.
The back cover of The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth by Zoë Schlanger. Click on the image to go to the Amazon page for the hardback version of the book.
Super fact 82 : All known cellular life descends from a single Last Universal Common Ancestor (LUCA). All animals, all plants, fungi, algae, green and red algae, kelp, phytoplankton, cyanobacteria, amoebas, amoebozoa, diatoms, stramenopiles, rhizaria, hacrobia, all eukaryote, all archaea, all bacteria, all the millions of species on Earth come from one single ancestor known as the Last Universal Common Ancestor – LUCA. Viruses are an exception, but viruses are not considered life.
Last Universal Common Ancestor creation Shutterstock Asset id: 2666598705 by Shutterstock AI
The answer is genome mining. By surveying nearly 2000 genomes of modern microbes we not only know that all life has a common ancestor (LUCA), that lived roughly 4.2 billion years ago, but we also know that it thrived near hydrothermal vents as part of a larger microbial community. This is analogous to another of my posts “Humans and Chimpanzees Have a Common Ancestor”. By sequencing human DNA and chimpanzee and bonobo DNA we know that humans and chimpanzees have a common ancestor. No fossils, or other information from the past is needed. DNA is a great tool for determining relationships between species and for finding information about past life, without the need of fossils.
To be more specific, the detailed biochemical similarity of all current life makes the existence of LUCA widely accepted by biochemists. There is a Universal Genetic Code, which means that nearly all living things use the same DNA/RNA-based genetic code to translate genetic information into proteins. There is a shared molecular machinery, for example, all life relies on ribosomes for protein synthesis, similar energy carriers like ATP, and the same 20 amino acids. All life uses the same mirror-image form of molecules, a signature of a single, common ancestry. In addition, there is a “core” set of 355 gene families present in both modern bacteria and archaea, which were likely inherited from LUCA. Finally, we have phylogenetic mapping, protein-sequence-based phylogenetic trees converge on a single root, indicating a common ancestry for all life. See the phylogenetic tree of life below.
Below is another view of the diversification of life that focuses on the inventions made by life.
The evolutionary tree of life showing diversification, branching and key characteristics of each branch. Shutterstock Asset id: 228953155 by Zern Liew
It should be noted that in addition to viruses there were likely other forms of life that existed alongside LUCA or before it. There was likely non-cellular life as well as cellular life that died out, RNA-based life, self-replicating nucleic acids, etc. It should also be noted that if some of the large viruses were to be reclassified as life, or a life form not based on LUCA were to be discovered then our “current LUCA” would no longer be LUCA, but just the ancestor of “almost all life”. That would still be amazing, just slightly less so.
The existence of LUCA brings up an interesting question. What would happen if we found DNA based life on another planet and its DNA showed that it also originated from LUCA ?
Super fact 72 : About three billion years ago Cyanobacteria evolved a new type of photosynthesis that used sunlight, water, and carbon dioxide to create energy, while releasing oxygen as a waste product. This transformed the atmosphere and enabled complex life by allowing aerobic respiration to evolve. This invention turned the sky blue, gave us the protective ozone layer, but also caused climate change resulting in massive extinctions.
An example of a Cyanobacteria. From Wikipedia. Luke Thompson from Chisholm Lab and Nikki Watson from Whitehead, MIT, CC0, via Wikimedia Commons
Cyanobacteria, also known as blue-green algae, are bacteria capable of oxygenic photosynthesis. Between 3.4 and 2.5 billion years ago they developed a new and very effective form of photosynthesis, which took advantage of highly abundant resources, using sunlight, water, and carbon dioxide turning it into sugar and releasing oxygen as byproduct. This is referred to as the Great Oxidation Event. You can read more about this event here, here, here, here, here, or in the book Becoming Earth by Ferris Jabr.
The atmosphere prior to the Great Oxidation Event was primarily composed of volcanic gases including nitrogen, carbon dioxide, water vapor, methane and ammonia, but almost no free oxygen. The Great Oxidation Event changed all this, but it likely took at least 200 million years.
Cyanobacteria vector illustration. Biological blue green algae diagram with carboxysome, thylakoid and phycobilisome parts location inside cell. Asset id: 1687712761 by VectorMine
A Microbial Great Extinction and Snowball Earth
Oxygen was a toxic gas to many early microbes forcing them to adapt or perish. In addition, the change in the atmospheres composition changed the climate, resulting in a severe global cooling referred to as Snowball Earth. This caused a great extinction, perhaps the most severe extinction in Earth’s history. It is not included among the five mass extinction events in Earth’s history because it happened very early in Earth’s history when only primitive microbial life existed and fossil evidence from that time is nearly non-existent. The definition of a mass extinction event is that at least 75% of the world’s species are lost during a short period of time – geologically speaking. This period is not clearly defined but often defined to be two million years. It is very difficult to determine whether the great extinction following the Great Oxidation Event qualifies as a mass extinction event. To read about mass extinctions click here.
Proterozoic era in the history of the Earth. Snowball earth. Global glaciation of the Earth. Asset id: 2010272753 by Elena Kelman
The Ozone Layer and the Blue Sky
Oxygen is also responsible for formation of the ozone layer in the atmosphere. The UV radiation from the sun split oxygen molecules, which consist of two oxygen atoms, into two separate atoms of oxygen, which then reacted with another oxygen molecule to generate ozone, and oxygen molecule consisting of three oxygen atoms. Ozone acts as a natural sunscreen to prevent harmful UV radiation from reaching the earth. Therefore, oxygen not only enables land dwelling complex multicell organisms to exist by allowing aerobic respiration to evolve, but also by protecting life from too much UV radiation.
As mentioned above, the atmosphere prior to the Great Oxidation Event was primarily composed of volcanic gases and almost no free oxygen. The color of the sky was likely orange, brown. As oxygen replaced the existing gases the sky slowly turned blue. Oxygen molecules along with Nitrogen molecules scatter blue light from the sun through a process called Rayleigh scattering, making the sky appear blue.
Cyanobacteria and The Great Oxygenation Event
It should be noted that there were other geological and biological processes that were responsible for this permanent shift in the Earth’s system, including changes in the composition of volcanic emissions and chemical reactions that allowed atmospheric hydrogen to escape to space, leaving behind an excess of oxygen molecules. However, whatever the exact mix of mechanisms, cyanobacteria were undoubtedly a critical source of accumulating oxygen. It is possible that tectonic activity altered the cycling and distribution of phosphorus and other nutrients essential for cyanobacteria. To read more see the book Becoming Earth by Ferris Jabr.
