Without carbon dioxide the Earth would freeze

Superfact 91: Without greenhouse gases, the Earth’s average surface temperature would drop from the current 15 Celsius (59 Fahrenheit) to approximately -18 Celsius (0 Fahrenheit), which is an average temperature drop of 33 degrees Celsius. If you removed carbon dioxide from the atmosphere but let the other greenhouse gases stay the drop would be 30 degrees Celsius. In both cases most of the planet would freeze. This is referred to as snowball Earth.

Snowball Earth or Snowball planet. In the picture Earth is seen from space. It is covered by ice all over. | Without carbon dioxide the Earth would freeze
Shutterstock Asset id: 2750019199 by Shutterstock AI

Our planet is much warmer than it otherwise would be because of greenhouse gases. Carbon dioxide, or CO2, is the most important of the greenhouse gases. We are rapidly warming the atmosphere with our carbon dioxide emissions as explained by these articles from NASA and NOAA.  If we did the opposite and removed CO2 from the atmosphere we would be cooling the atmosphere. As mentioned, if we removed all greenhouse gases from the atmosphere the planet’s average temperature would drop by 33 degrees Celsius and this NASA article claims it would take 50 years to reach that temperature.

If we removed only carbon dioxide and let all the other greenhouse gases remain, we would get an almost as big temperature drop of 30 degrees Celsius according to the calculations done by this article. Some of you may know that water vapor provides a larger portion of the warming than CO2. In fact, 75% of the greenhouse effect is caused by water vapor and clouds. This seems contradictory. However, when the atmosphere cools, the water vapor will rain out of the atmosphere unlike CO2. Basically, water vapor will adjust to the temperature whilst CO2 is  forcing the temperature. It is crucial to understand this difference. That is why CO2 is the most important greenhouse gas. In summary, we need just the right amount of CO2 for a healthy climate.

I consider this a super fact because it is true, it is an important fact, and I believe it is a surprising fact to many, especially those who doubt carbon dioxide’s importance to the global warming we are experiencing. I called it global warming but whether you call it global warming, climate change, or climate disruption, we are talking about the same thing.

Snowball Earth

Mountains covered by ice and snow and valleys covered by a thick ice sheet.
Shutterstock Asset id: 2749007159 by Shutterstock AI

Scientists believe there have been at least two major “Snowball Earth” events between 720 and 635 million years ago where ice and snow covered nearly the entire planet. These snowball earth events were triggered by natural events, likely a plunge in sunlight, followed by a plunge in carbon dioxide not entering the atmosphere, and amplified by sunlight reflecting back into space. All three effects made Earth cooler. The recent ice ages were likely caused primarily by earth’s orbital cycles. Climate changed in the past due to natural phenomena, but that does not mean that the current very rapid warming (rapid geologically speaking) is natural.

If you want to understand why we can be so sure that it is our CO2 emissions that is causing the current global warming, not the sun, not volcanoes, not orbital cycles, and not another natural process, please check out the list of evidence in the second part of this post “Global Warming is Happening and is Caused by us”.

Hothouse Venus

What we see in the photo is a large white smooth planet. The MESSENGER spacecraft snapped a series of images as it approached Venus on June 5, 2007. The planet is enshrouded by a global layer of clouds that obscures its surface to the MESSENGER Dual Imaging System (MDIS) cameras. This single frame is part of a color sequence taken that helped the MESSENGER team calibrate the camera in preparation for the spacecraft's first flyby of Mercury on January 14, 2008.
Image taken by the NASA MESSENGER as it approached Venus on June 5, 2007. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington, Public domain, via Wikimedia Commons. The image is taken from this Wikipedia article.

The opposite of snowball Earth is hot Venus. Venus is the hottest planet in the solar system due to an extreme runaway greenhouse effect. Surface temperatures are averaging around 465 degrees Celsius (870 degrees Fahrenheit). The thick atmosphere of Venus is composed primarily of carbon dioxide with clouds of sulfuric acid. This causes a greenhouse effect that traps heat.

Despite the fact that Mercury is much closer to the sun (58 million kilometers versus 108 million kilometers) and receives nearly four times as much sunlight per unit area than Venus, Mercury is on average much cooler. The reason is that Mercury’s atmosphere is thin and without a greenhouse effect.

The YouTube video below from NASA explains the greenhouse effect on Venus. It is just one minute long.



I would also like you to take a look at this post:, “The Greenhouse Effect: From Early Chemistry to the Keeling Curve” by Craigavad miscellany a science blog written by a retired academic. It is a very educational and interesting post related to this topic.




To see the Other Super Facts click here

Large Language Models is just One Branch of Artificial Intelligence

Superfact 90: Large Language Models (LLMs) such as ChatGPT, Claude, Llama and Gemini are just one type of popular applications of Artificial Intelligence among hundreds of applications of Artificial Intelligence, and LLMs represents just one branch of Artificial Intelligence.

White female AI robot using a microscope in the scientific laboratory | Large Language Models is just One Branch of Artificial Intelligence
Artificial intelligence and research concept. Shutterstock Asset id: 2314449325 by Stock-Asso

LLMs are currently the most popular “viral” AI. We can all access LLMs in our browsers. This has created the common misconception that Artificial Intelligence is the same as Large Language Models. However, LLMs represent only one branch of narrow AI systems designed to perform specific tasks.

Applications of Artificial Intelligence other than what Large Language Models are used for include robotics, robot motion planning, advanced control systems using AI, self-driving cars, image processing, optical character recognition, classification, facial recognition systems, medical imaging diagnostics, game playing such as chess playing computers, financial fraud detection, cybersecurity, investment robots, route optimization, mathematical proof generation, recommendation algorithms, virtual assistants, programming code generation, smart home devices, drug discovery, and that is just for starters.

There are probably many applications and types of Artificial Intelligence that we have not yet invented.

C3P0 and R2D2 from Star Wars
Two Robots powered by Artificial Intelligence. Shutterstock Asset id: 558350728 by Willrow Hood.

LLMs use large neural networks with many hidden layers, so called deep learning algorithms, and they employ the Rumelhart backpropagation learning algorithm invented by David Rumelhart, Geoffrey Hinton, and Ronald Williams. Clearly neural networks with multiple hidden layers and using the Rumelhart backpropagation algorithm are incredibly successful but it is just one of many kinds of Artificial Intelligence algorithms, and who knows what we will see in the future. Related to this post is my previous post Artificial Intelligence is Not New. We have only just begun.

I consider this a super fact because it is true, kind of important, and I believe that the multitude of Artificial Intelligence algorithms and applications is a surprise to many.

The many Artificial Intelligence Algorithms

AI Humanoid Face Concept. Technology Digital Robot Head Side View with Circuit Board Components. Tech Blue Background. Artificial Intelligence Agent or Assistant Concept. Vector Digital Illustration. | Large Language Models is just One Branch of Artificial Intelligence
Shutterstock Asset id: 2645975149

Due to the great improvement and success of Neural Networks, they have become very popular and Large Language Models use very large Neural Networks with multiple hidden layers (employing the Rumelhart back propagation algorithm). You can read more about that here.

However, there are many other AI algorithms, hundreds, maybe thousands. One example is genetic algorithms. These are types of algorithms that mimics evolution. They iteratively select a set of the best candidate solutions, then combine them (crossover), and also add random changes (mutation) to generate new solutions. Then select the best solutions and then you do it again. Selecting the best solutions corresponds to natural selection. I tried out such algorithms at my work, and over many iterations / generations you can get some impressive results. It is easy to understand how a complex organ such as an eye can evolve in a similar way in nature.

One type of decision tree based machine learning algorithm that I used specifically for classification tasks at work was C4.5 and C5. More specifically I used this type of machine learning algorithm for evaluating the results from automatic mail sorting systems. Basically, how well can a result from a certain machine be trusted. I don’t remember exactly but my classes were something along the line of super reliable, pretty reliable, average, and this result probably sucks. Other examples of this type of machine learning are ID3, Random Forest, Gradient Boosting, and CART. These types of algorithms are still very popular.

One advantage of using decision tree based machine learning over neural networks for the same task is that when a decision has been made you can follow the decision tree backwards and see why a decision / classification was made. In fact, if you have less than 100 parameters you could likely do it over a lunch. When a neural network makes a decision all you have is a large bunch of numbers that were spit out by an algorithm that looped possibly thousands of times and changing all the numbers every time. You can’t backtrack and figure out exactly how a decision was made. You just have to trust the neural network. The advantage of a neural network in this situation is that if it is trained properly, it is likely to have a better result.

Another type of algorithm used in Artificial Intelligence is search algorithms. For robot motion planning I used an algorithm called A* or A-star, which is a very efficient pathfinding algorithm. It comes in dozens of variants and there are hundreds of other types of search algorithms.

These are just a few examples, but there’s also knowledge based agents, AI-agents with reinforcement learning algorithms, algorithms based on Bayes’ Theorem, Vector Machines, Markov Decision Processes, clustering algorithms,  K-nearest neighbor (KNN) algorithm, simulated annealing, hill climbing,  the ant colony optimization algorithm, and of course neural networks and there are also many types of neural networks. I used a relatively unknown form of artificial intelligence called reflex control for my robotics research. The point is, there is zoo of artificial intelligence algorithms out there. Deep learning neural networks are very popular AI algorithms but far from the only ones.

My Personal Experience with Artificial Intelligence

In 1986, when I was in college in Sweden, I took a class in the LISP programming language. LISP was the first Artificial Intelligence programming language, and it was invented in 1958. In 1987, as a university level exchange student, I took a class called Artificial Intelligence at Case Western Reserve University. That same year I also took a class called Pattern Recognition which introduced neural networks to me.

In 1986 a landmark paper was published by David Rumelhart, Geoffrey Hinton, and Ronald Williams introducing the Rumelhart backpropagation algorithm. Geoffrey Hinton received the Nobel Prize in physics in 2024. David Rumelhart and Ronald Williams were both dead and could therefore not receive the Nobel Prize. The Nobel Prize was also given to John J. Hopfield, another pioneer in neural networks. He invented the Hopfield network. You can read more about neural networks and the Nobel Prize in physics in 2024 here.

The Rumelhart backpropagation algorithm was a giant leap forward for neural networks and for Artificial Intelligence and it is the algorithm used by ChatGPT and the other large language models. Geoffrey Hinton is often interviewed in media and often presented as the father of Artificial Intelligence. He is not, but he us arguably partially responsible for the greatest leap forward in neural networks, as well as Artificial Intelligence.

In the pattern recognition class, we used the Rumelhart backpropagation algorithm on a simple neural network to read images with text. Later I did research in the field of Robotics where I implemented various Artificial Intelligence algorithms as mentioned above. I have a PhD in Applied Physics and Electrical Engineering with specialty in Robotics. Later I would use artificial intelligence algorithms in my professional career.

A picture of a large silver colored industrial robot.
I used mostly the seven joint Robotics Research Corporation Robot for my robotics research. The robot was able to detect and avoid colliding with the objects surrounding it. I used echolocation for object detection.

My previous posts on Artificial Intelligence, “Artificial Intelligence is Not New”, and “The Nobel Prize in Physics and Neural Networks”, describe how neural networks work in greater detail.

Note on potential harm of AI

The potential harm of AI is a related and important topic that I did not address. I don’t know much about this topic. However, Grant from “Grant at Tame Your Book” have written an excellent, well research and professional post about this issue called Don’t Confuse AI with a Benign Tool. Please check it out.




To see the Other Super Facts click here

Wind Energy is Indeed Clean Energy

Superfact 87: Wind energy is a clean, renewable, and sustainable power source that produces no atmospheric emissions or water pollution during operation. Manufacturing and installation have a small carbon footprint that is much smaller than the carbon footprint of the fossil fuels they potentially replace.

Wind turbines with a background of mountains, clouds and a blue sky. | Wind Energy is Indeed Clean Energy
Photo from pexels.com

There is a lot of disinformation being spread about wind power. One recent example is the TV series Landman which presents demonstrably false claims as facts. In Texas where I live the problem with deceitful anti-renewable propaganda is especially severe. It is important to check with reputable sources before you believe what you come across. Wind energy is not 100% clean and not without issues but it is much safer and cleaner than the fossil fuels they potentially replace. Below is a two minute video that explains this.

The graph below from Our World in Data depicting lifetime greenhouse gas emissions (construction, operation, disposal) show that the lifetime greenhouse gas emissions of coal power are 88 times higher than those of wind power and kill 615 times as many people as wind power. The lifetime greenhouse gas emissions of natural gas are 40 times higher than those of wind power and kill 460 times as many people as wind power. The difference is staggering. When someone tells you that there’s nothing clean about wind power, they are not just lying to you, they are lying very big.

In the graph below, greenhouse gas emissions is measured of CO2 equivalents per Gigawatt-hour of electricity over the lifecycle of the power plant. 1 Gigawatt-hour is the annual electricity consumption of 150 people in the EU. Death rate from accidents and air pollution is measured as deaths per Terawatt hour of electricity production. 1 terawatt hour is the annual electricity consumption of 150,000 people in the EU.

The graph depicts death rates and greenhouse gas emissions per unit for different energy sources including coal, oil, natural gas, biomass, hydropower, wind, nuclear power, and solar.
Death rates from fossil fuels and biomass are based on state-of-the art plants with pollution control in Europe and are based on older models of the impacts of air pollution on health. This means these death rates are likely to be very conservative. For further discussion see our article: OurWorldinData.org/safest-sources-of-energy. Electricity shares are given for 2021. Data sources: Markandya & Wilkinson (2007); UNSCEAR (2008: 2018); Sovacol et al. (2016); IPCC AR5 (2014); UNECE (2022); Ember Energy (2001). OurWorldinData.org – Research and data to make progress against the world’s largest problems. Licensed under CC-BY by the authors Hannah Ritchie and Max Roser. Citation : Hannah Ritchie (2020) – “What are the safest and cleanest sources of energy?” Published online at OurWorldinData.org. Retrieved from: ‘https://archive.ourworldindata.org/20260202-100556/safest-sources-of-energy.html’ [Online Resource] (archived on February 2, 2026).

As you can see wind power is safe and emits very little greenhouse gases over its lifetime. In addition, there is no water impact associated with the operation of wind turbines, but a relatively small amount is used in manufacturing. There are other issues with land use, sounds, rare earth mining, waste, and effects on wildlife particularly birds.

However, these issues are in general smaller than depicted must be compared to issues with the fossil fuels they replace. For example, 15 billion tons of fossil fuels (including 9 billion tons of coal) are mined every year and burned whilst the annual mining for all clean energy technologies is around 7 million tons (2,000 times less). More about birds in the next section. Overall wind energy is a clean, renewable, and a sustainable power source. You can read more about this here, here, here, or here.

I am referring to this fact as a super fact because, it is true, an important topic, and yet it’s a fact that is difficult for many people to believe. Too much misinformation has been spread about wind power. I expect some people to dismiss this fact out of hand. But that is the point of super facts, they are true but hard to believe for many, or surprising, and perhaps even shocking.

Wind power saves a lot more birds than it kills

It may come as a surprise to some, but wind power is not a major cause of bird death. Wind farms are estimated to be responsible for losing less than 0.4 birds per gigawatt-hour (GWh) of electricity generated, compared to over 5 birds per GWh for fossil fueled power stations. This means that replacing fossil fuels with wind power saves a lot more birds than wind power turbines take. In addition, cats, windows, cars, poison and powerlines are examples of things that kill a lot more birds than wind power does. Cats kill thousands of times more birds than wind power does, and this usually does not bother us. Note I love both dogs and cats.

It is difficult to make exact estimates of bird deaths but below are some interesting graphs from reputable sources, confirmed by many other studies and analysis, such as this overview from MIT and this analysis by Hannah Richie. The numbers aren’t the same, but they make the same point. You can read more about this here.

The graph shows that Wind Turbines kill 328,000 birds per year in the US, Electrocutions kill 6,250,000 birds, Collisions with powerlines kill 32,500,000 birds, Poison kills 72,000,000 birds, Vehicle collisions kill 214,500,000 birds, Collisions with glass kill 676,500,000 birds, and cats kill 1,850,700,000 birds per year in the US.
From Wikipedia: Universiteit van Nederland, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons
Bar graph showing cats killing an estimated 2,400 million birds per year, buildings killing an estimated 599 million birds per year, automobiles killing an estimated 200 million birds per year, pesticides killing an estimated 67 million birds per year, powerlines killing an estimated 28 million birds per year, communication towers killing an estimated 6.6 million birds per year, and wind turbines killing an estimated 1.2 million birds per year. | Wind Energy is Indeed Clean Energy
An alternative graph taken from Hannah Richie / Our World in Data, using alternative sources essentially showing the same thing. Sources: Loss et al. (2015), (2013), US Fish and Wildlife Service; Subramnayan et al. (2012), American Bird Conservancy (2021).

That does not mean we shouldn’t do our best to reduce bird deaths from wind power stations. However, don’t fall for the misinformation that is trying to paint it is a big problem specifically for wind power.

Wind power turbines by the seashore. The sun is setting. | Wind Energy is Indeed Clean Energy
Photo from pexels.com

Wind Power is Inexpensive

Finally, a bit of a deviation from the main topic. In addition to being a relatively clean, renewable, and sustainable power source, wind power is now relatively cheap, which explains its recent success around the world. I am bringing this up because another widespread myth about wind power is that it is expensive and wouldn’t survive without subsidies.

Practically all energy sources are subsidized, and fossil fuels have a long history of government subsidies. Below is the average unsubsidized levelized cost of energy according to Lazard. Levelized means that construction costs, land rent, and other costs not directly caused by electricity generation are taken into consideration. Notice how cheap wind is (blue line). This graph is for the United States.

The image shows 8 graphs representing the price of Nuclear, Gas (peaker), Thermal Solar, Coal, Geothermal, Natural Gas, Solar Panels, and Wind. Today Wind is the cheapest.
Average unsubsidized levelized cost of energy. Notice that the light blue line indicates that wind power is pretty cheap. Mir-445511, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons.

Windpower is not only relatively cheap. Wind power is one of the most efficient and sustainable energy sources available. The energy required to manufacture, install, and maintain wind turbines is small compared to the energy they produce over their lifespan. This is known as their energy return on investment (EROI), which is quite favorable for wind energy. The Institute of Environmental Management and Assessment (IEMA) states that the average wind farm will pay back the energy that was used in its manufacture within 3-5 months of operation. This article in the journal Renewable Energy found that the average windfarm produces 20-25 times more energy during its operational life than was used to construct and install its turbines. It included data from 119 turbines across 50 sites going back 30 years.

It is important to be aware that there are many false claims floating around about wind power. The sound from wind power stations does not cause cancer, it does not use any other energy sources while operating; it solely harnesses the kinetic energy from the wind to generate electricity, meaning it only relies on wind to function as its primary energy source. Windpower is not a major cause if bird deaths. To read more about false claims about wind power click here.

Conclusion

There are positive and negative aspects of wind power, like any other source of energy. One issue with wind power (and solar) is that it is an intermittent source of energy. When the wind is not blowing you need other sources of energy (until there is sufficient energy storage). This is less of a problem when you have a mix of energy sources and in practice it has not been a big problem so far. However, what we know is that Wind Energy is indeed clean energy, much cleaner than the fossil fuels they potentially replace, and also relatively cheap, even without subsidies.

Other Posts by Me Related to Wind Power




To see the Other Super Facts click here

Early Homo Sapiens lived at the same time as many other human species

Super fact 86 : Early humans, early homo sapiens, lived at the same time as many other human species including Neanderthals, Denisovans, Homo floresiensis, Homo naledi, Homo luzonensis. Homo heidelbergensis, Homo erectus, and maybe other species as well.

Photo of a reconstruction of a Neanderthal man. | Early Homo Sapiens lived at the same time as many other human species
Reconstruction of a Neanderthal by Natural History Museum. Werner Ustorf, CC BY-SA 2.0 https://creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons.

Homo sapiens co-existed with several other Homo species. Homo erectus and Homo heidelbergensis are direct ancestors to Homo sapiens that survived long enough to exist at the same time as Homo sapiens.

Homo sapiens emerged around 300,000 years ago in Africa and Homo erectus died out around 100,000 years ago and Homo heidelbergensis died out around 200,000 years ago. Homo floresiensis died out 50,000 years ago, the most recent Homo luzonensis is 50,000 years old but they may have survived longer, Homo naledi existed approximately 335,000 to 236,000 years ago, Neanderthals interbred with homo sapiens and died out around 40,000 years ago, the Denisovans also interbred with homo sapiens and died out around 30,000 to 50,000 years ago. You can read more here and here.

You may wonder how different species can interbreed with each other. More on that later in this post.

I consider this a super fact because it is true, surprising to those who did not know this, and ancient human history is kind of important. Even if you knew that homo sapiens lived along other homo species the fact that the world used to be so crowded with different homo species may come as a surprise. Where did they all go?

Direct Ancestors of Homo Sapiens

Homo heidelbergensis is widely considered a pivotal common ancestor to Homo sapiens, Neanderthals, and Denisovans. Since Homo Erectus is a direct ancestor to Homo heidelbergensis it is also a direct ancestor to Homo sapiens, Neanderthals, and Denisovans. Homo Erectus is also a direct ancestor to Homo floresiensis but Homo heidelbergensis is not considered an ancestor to Homo floresiensis. The picture below shows the direct ancestors to Homo Sapiens.

The skulls are from left to right Australopithecus africanus 3.3 - 2 million years ago, Homo habilis 2.4 to 1.5 million years ago, Homo erectus 1.6 to 600 thousand years ago, Homo heidelbergensis 700 thousand to 200 thousand years ago, early homo sapiens 300 thousand to 45 thousand years ago, anatomically modern human 130 thousand years ago until now.
Skulls of successive (or near-successive, depending on the source) human evolutionary ancestors, up until ‘modern’ Homo sapiens. Mya – million years ago, kya – thousand years ago. SimplisticReps, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

Geographic spread of Homo Sapiens and other Homo Species

Homo heidelbergensis is an ancestor to Neanderthals, Denisovans and Homo sapiens (and Homo erectus is an ancestor to Homo heidelbergensis). However, whilst Neanderthals emerged in Europe and Asia, Denisovans evolved in Asia, and Homo sapiens emerged in Africa.

The map shows the movement of Homo heidelbergensis originating in Africa and moving into Europe and Asia with Neanderthals (in yellow) emerging in Europe and moving into Asia. The Denisovans emerged in Asia and spread further east. | Early Homo Sapiens lived at the same time as many other human species
The evolution and geographic spread of Denisovans as compared with Neanderthals, Homo heidelbergensis and Homo erectus. John D. Croft at English Wikipedia, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.

The map below indicates where skeleton remains of Neanderthals had been found as of 2017.

This map of Europe and West Asia shows the region where Neanderthals have been found.
Known Neanderthal range in Europe (blue), Southwest Asia (orange), Uzbekistan (green), and the Altai mountains (violet), as inferred by their skeletal remains (not stone tools). There were 165 such places by 2017. Nilenbert, N. Perrault, auteur du guide complet du canotageI, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/&gt;, via Wikimedia Commons.

Interbreeding and Defining a Species

Homo Neanderthalensis and Homo Sapiens (or Homo Sapiens Sapiens) interbred, and so did Homo Denisova and Homo Sapiens, and Homo Neanderthalensis interbred with Homo Denisova. What a mess! Homo Neanderthalensis and Homo Sapiens were different species, so it may seem strange that they could interbreed. However, species is a complex concept.

Speciation is considered relative. It is often said that two animals belong to the same species if they can interbreed in nature and produce viable, fertile offspring. However, it is not 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. 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.

The picture depicts different subspecies as little colored circles centered around a big lake. The color changes a little bit at the time. All the circles next to each other can 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&gt;, via Wikimedia Commons.

For the case of Neanderthals and Homo sapiens (and Denisovans); at certain points in history, you could consider Homo Neanderthalensis and Homo Sapiens to be different subspecies rather than different species. That is why you sometimes hear the terms Homo Sapiens Neanderthalensis and Homo Sapiens Sapiens. I can add that Homo sapiens certainly got around, as you can see on the map below.

A world map showing portions of Africa being yellow and red, and portions of Asia being yellow and dark yellow with red arrows representing migrating Homo Sapiens. The map features several time markers representing the arrival of Homo Sapiens. | Early Homo Sapiens lived at the same time as many other human species
The spread of Homo Erectus (yellow), Homo Sapiens (red) and Homo Neanderthalensis (dark yellow). NordNordWest, Public domain, via Wikimedia Commons.

Is Thomas Wikman a Neanderthal ?

I can add that genetic testing can reveal how much Neanderthal DNA you have. I took a test with 23AndMe to find out about my ancestry (it was 98% Scandinavian and Finnish) and to find out about my risk for genetic illnesses. 23AndMe also told me that I was in the 99 percentiles with respect to carrying Neanderthal genes, meaning that I had unusually many Neanderthal genes. I joined the 23AndMe Neanderthal club (you had to be in the 98 percentile).

However, I quit after people in the club started saying that we should demand reparations from those with less Neanderthal genes because they exterminated us. It might have been a bizarre joke, but I decided not to stay around to find out. Later, after 23AndMe went bankrupt, I deleted mine and my wife’s data and quit. I was afraid 23AndMe might sell the DNA data to health insurance companies.

Man geneticist. Doctor sits at table in genetic laboratory. Chains of DNA or RNA. Sequencing human genome. Doctor studies DNA. Geneticist conducts scientific experiments Geneticist looks at test tubes
Geneticist sequencing human genome Asset id: 2479929725 by FOTOGRIN

This is some other evolution and natural history related posts



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Birds are Avian Dinosaurs

Super fact 84 : Modern birds are classified as part of the clade Dinosauria. They are direct descendants of small, feathered maniraptoran dinosaurs that survived the Cretaceous-Paleogene extinction event 66 million years ago. Maniraptoran dinosaurs in turn are a major subgroup of coelurosaurian theropod dinosaurs. In other words, birds are avian dinosaurs.

3D illustration showing two carnivorous dinosaurs and two large herbivores looking up at a burning asteroid. | Birds are Avian Dinosaurs
Some dinosaurs survived the Cretaceous-Paleogene extinction event 66 million years ago. Shutterstock Asset id: 2196200279 by funstarts33

Birds are descendants of specialized maniraptoran theropod dinosaurs that survived the extinction event that killed most dinosaurs 66 million years ago. Maniraptoran dinosaurs in turn are a major subgroup of Tyrannoraptora, which include the well-known Tyrannosaurus Rex. Tyrannoraptora  in turn is a major subgroup of coelurosaurian theropod dinosaurs. Both the well-known dinosaur called velociraptor, and birds belong to the group Maniraptora. Even though the velociraptor was not a bird they shared many bird-like features, including feathers, wishbones, hollow bones, and similar wrist joints.

A colorful velociraptor covered in feather. It does not look like it could fly.
Velociraptor with feathers (well a little bit). Shutterstock Asset id: 2636534673 by Shutterstock AI Generator

Birds evolved during the Jurassic period from two-legged, carnivorous, and often feathered dinosaurs, and are the only surviving dinosaurs. They have been classified as avian dinosaurs since the 1980’s. In other words, they are dinosaurs. Initially feathers evolved among dinosaurs for insulation, sexual display, and camouflage rather than flight. One of the early birds was Eoconfuciusornis. It lived 131 million years ago, long before the Cretaceous-Paleogene extinction event 66 million years ago. Eoconfuciusornis could fly and it had colorful feathers.

A black bird with a long retrix / tail sitting on a tree. | Eoconfuciusornis 130 million years ago. | Birds are Avian Dinosaurs
Eoconfuciusornis 130 million years ago. Nobu Tamura, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons

I brought up this fact in a recent post and I hinted that it was a super fact. It is true, surprising and kind of important. After all birds are all around us. In this post I am exploring the fact that birds are dinosaurs a little bit more than I did in my previous post. Below are a couple of modern birds.

A shoebill stork is a large gray-blue bird with a huge beak.
A shoebill stork standing at Ueno Zoo, Tokyo, five feet tall. Bob Owen, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons
A taxidermy mount of a turkey standing on our dining room table. | Birds are Avian Dinosaurs
A wild turkey in our dining room.

Feathered Dinosaurs

A lot of dinosaurs had feathers, and some could fly. That included many types of dinosaurs other than birds. Dinosaurs with feathers include, for example, Velociraptor, Deinonychus, Archaeopteryx (could fly), Microraptor (could fly), Rahonavis (could fly), Gallimimus, Ornithomimus, Yutyrannus huali, Psittacosaurus, Psittacosaurus, Sinosauropteryx, Sinornithosaurus, Eoconfuciusornis, Wulong, Psittacosaurus, Sciurumimus, Kulindadromeus, Caudipteryx, Utahraptor, Deinonychus, and even young T-Rex and many others. We know that at least some dinosaurs had feathers as well as colors based on fossil finds. Below are some illustrations.

A Gallimimus dinosaur covered in hair and feathers.
Life restoration showing an adult with feathers, based on those known from the related Ornithomimus. Picture is from here. PaleoNeolitic, CC BY 4.0 https://creativecommons.org/licenses/by/4.0, via Wikimedia Commons
A bird like dinosaur with feathers. It has huge claws.
Life restoration of Pyroraptor olympius. Picture is from here. Mette Aumala, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons.
Birds are Avian Dinosaurs | Reconstruction of the 2014 microraptorine dromaeosaur dinosaur, Changyuraptor yangi. This is a dinosaur with four wings.
Reconstruction of the 2014 microraptorine dromaeosaur dinosaur, Changyuraptor yangi. This is a dinosaur with four wings. The picture is taken from here. Emily Willoughby (e.deinonychus@gmail.com, http://emilywilloughby.com), CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons
Greyish bird like creature with a reptile like head.
Artistic restoration of D. albertensis Artistic restoration of D. albertensis. Picture from here. Fred Wierum, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons
Six dromaeosaurs are shown, all covered with feathers. Microraptor gui (flying), Velociraptor mongoliensis, Austroraptor cabazai, Dromaeosaurus albertensis, Utahraptor ostrommaysorum, Deinonychus antirrhopus. A human is shown on the left. Most of the dinosaurs are bigger than the human.
Size of Utahraptor (5) compared with other dromaeosaurs and a human. It is the biggest one in the picture. The picture is from here. Fred Wierum, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons.

Terror Birds and Other Giant Birds

After the Cretaceous-Paleogene extinction event 66 million years ago birds continued evolving. Some of them became large standing 1 – 3 meters (3-10 feet) and weighing hundreds or even thousands of pounds. From about 53 million years ago until 100,000 years ago there were large birds that we refer to as Terror Birds. They lived at the same time as humans. However, there were other large and scary birds. Dromornis stirtoni was a flightless bird that lived 7-8 million years ago, it was over three meters in height (10 feet) and weighed 500-600 kilograms (1,100 to 1,300 pounds). Below are some illustrations.

pencil drawing, digital coloring of Paraphysornis brasiliensis, a Terror Bird. | Birds are Avian Dinosaurs
Paraphysornis brasiliensis, a Terror Bird, 8 feet tall weighing 400–530 pounds, this is a terror bird from the Early Miocene of Brazil,: Snowmanradio (talk)Paraphysornis_BW.jpg:  Nobu Tamura (http://spinops.blogspot.com), CC BY 3.0 <https://creativecommons.org/licenses/by/3.0&gt;, via Wikimedia Commons.
The Kelenken, Devincenzia, Phorusrhacos, and Titanis birds are all larger than the human standing on the left hand side. Kelenken guillermoi is the largest.
Size comparison of some phorusrhacids (Terror Birds), including Kelenken, Devincenzia, Phorusrhacos, and Titanis. Picture taken from here. PaleoNeolitic, CC BY 4.0 <https://creativecommons.org/licenses/by/4.0&gt;, via Wikimedia Commons.
A flightless bird with huge yellow beak. | Birds are Avian Dinosaurs
A pencil-drawn reconstruction of Dromornis stirtoni. Picture is taken from here. Nobu Tamura (http://spinops.blogspot.de), CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons