From time to time, I teach classes at Anderson University. While I usually teach science for science majors, over the past few years, I have been co-teaching a class with Dr. Scott Carr called “Teaching STEM in the Elementary Classroom.” It is designed to give elementary education majors the tools they need to incorporate science, technology, engineering, and math lessons in their K-6 classrooms.
I started teaching it just because I enjoy working with Dr. Carr, but I have continued teaching it because the class is really fun. A good portion of the class time is spent having students come up with experiments that their students could either do or watch. Of course, I have seen all sorts of science experiments for elementary students, and my elementary series actually contains a total of 450 of them. Nevertheless, every year I see at least one new experiment or a new variation on an experiment I already know. This year is no exception. We have only been in class for two weeks, and already, a student named Melodie Nord presented a great experiment that shows gravity accelerates all objects at the same rate. A slow-motion video of it is given below:
As you can see in the video, water is falling out of a hole near the bottom of the cup in a stream. However, once the cup is released, the water stops falling out of the hole. It is still falling, of course, but the cup is falling with it. Since the cup and its entire contents fall at the same rate as the water that would have come out of the hole, the cup “keeps up” with the stream that was coming out of the hole. As a result, there is no stream of water. This shows that whether it is a tiny drop of water or a cup full of water, gravity accelerates everything at the same rate, regardless of mass.
I have a plaque on my wall that says “Docendo Discimus,” which is a Latin proverb that means, “By teaching, we learn.” It is true whether I am teaching nuclear physics at the graduate level or STEM for elementary education majors!
The more we learn about the universe, the more we see that it is a product of design. Indeed, for quite some time now, many scientists have recognized that the universe is finely-tuned for life. There are many parameters that govern how things happen in the universe, and they all have the characteristics of being just what they need to be for life to flourish. An electron, for example, is precisely as negative as the proton is positive, despite the fact that they are very, very different particles. If the charges were off by as little as one billionth of one percent, the resulting electrical imbalance in molecules would make even very small objects too unstable to form.1 The most obvious explanation for such fine-tuning is that the universe has been designed for life.
Now, of course, if you don’t want to believe that the universe is a product of design, you can offer any number of desperate alternatives. Perhaps we are just very fortunate. After all, if the universe weren’t designed for life, we wouldn’t be here to study it, so the very fact that we can discover these relationships tells us that the universe just happened to evolve into one that appears to be finely-tuned for life. You could also suggest that there are a ridiculously large number of universes out there. Most of them don’t have life, because they don’t have the proper parameters. However, if there are many, many universes, there’s a high likelihood that at least one will have all the right parameters, making it appear to be finely-tuned for life. You could also argue that there are actually a lot of combinations of parameters that might work for life; we just don’t know them. In that case, the universe’s apparent fine-tuning is an illusion.
Over the past few days, several people have sent me articles like this one, which makes a rather fantastic claim:
The Aldabra white-throated rail bird was declared extinct, a victim of rising sea levels almost 100,000 years ago.
However, the flightless brown bird has recently been spotted – leaving scientists scratching their heads as to how – and why – the species has come back to life.
What do you conclude from reading that? The article seems to be saying that no one had ever seen this bird before; it was only known from the fossil record. Now, however, living versions of it have been seen, and how they came back from extinction is a mystery. Unfortunately, like many “science news” stories, this one distorts the science to the point that it is deceptive and misleading.
Let’s start with the bird that is being discussed. It’s the Aldabra white-throated rail, whose scientific name is Dryolimnas [cuvieri] aldabranus. It lives on the Aldabra atoll in the Indian Ocean and is nearly identical to white-throated rails (Dryolimnas cuvieri) found in other parts of the world, like Madagascar. However, the ones on the Aldabra atoll cannot fly, while the others can. As a result, the flightless birds on the atoll are considered a subspecies of the version that can fly.
While we cannot say for sure, the generally-accepted origin story for the Aldabra white-throated rail is that normal white-throated rails landed on the atoll, and since there were no predators there, they stayed. Since they didn’t need to fly anymore, they evolved into flightless birds over several generations. This makes sense, because when a population of organisms doesn’t need a particular biological trait, mutations can degrade those traits without affecting survivability. In addition, DNA is so incredibly well-designed that over the course of generations, it can “turn off” genes that are no longer used in order to save energy. As a result, it makes sense that these flightless birds are descendants from birds that could originally fly.
Why do these articles discuss the birds being extinct at one point? Because the authors of the scientific study looked at the fossil record of the atoll. Using scientifically-irresponisble dating methods, they came to the conclusion that the atoll was completely underwater about 140,000 years ago. When they looked at fossils they interpreted to be older than 140,000 years, they found two bones that seem identical to the corresponding bones in the Aldabra white-throated rails that currently live on the atoll. Thus, they conclude that these flightless birds lived on the atoll before it went completely underwater.
Well, since the birds couldn’t fly, the authors assume that they all died when the atoll was underwater. However, in fossils that they interpret as being deposited after ocean levels decreased and the atoll was no longer underwater, they found another bone that looks similar to the corresponding bones in white-throated rails that can fly. However, it is heavier and more robust than what is found in those birds, but still lighter than what is found in the flightless Aldabra white-throated rails. In other words, it seems to be “in between” the bone of a normal white-throated rail and a flightless white-throated rail. To them, that gives “irrefutable evidence” (their words) that the Aldabra white-throated rails evolved twice: once before the atoll went underwater, and once after.
While their interpretation of the evidence makes sense and is consistent with all the known data, their case is certainly not “irrefutable.” First, you have to assume that they are interpreting the fossil record correctly. There is a lot of evidence to indicate the earth isn’t anywhere close to 140,000 years old, and if that evidence is correct, then their entire explanation is wrong. Also, even if the earth is as old as these scientists want to believe, the authors’ explanation is not the only one consistent with the data. We know that flightless animals can move from place to place on floating mats of vegetation. This is called “rafting,” and it is used by both evolutionists and creationists to explain the worldwide distribution of certain animals. If the atoll flooded like the authors think, the flightless birds could have survived by rafting. What about that one bone that is “in between” the two subspecies? There are natural variations in all bones. A “more robust” bone from a normal white-throated rail can be explained by natural variation within a population of normal white-throated rails.
The main reason I am writing about this is not to argue with the authors. It’s to point out the deceptiveness of articles like the one I quoted at the beginning of the post. As I have said many times before, do not believe the things you read in the popular press when it comes to science. Most “science journalists” are profoundly ill-equipped to understand science, and usually quite poor journalists as well.
For more than 140 years, scientists have taught that lichens are the result of a relationship between a fungus and an alga (singular of algae). The fungus gives the lichen most of its visible characteristics and provides a protected place for the alga to grow. In exchange, the alga does photosynthesis and shares what it makes with the fungus. In other words, the fungus provides housing for the alga, and the alga provides food for the fungus. This is a form of symbiosis, in which organisms of different species exist in a long-term relationship. Since both organisms benefit in this symbiosis, it is called a mutualistic symbiosis, one of the most fascinating aspects of the biological world (see here, here, here, here, here, here, and here, for example).
Despite the fact that lichens have been studied for more than 140 years, there has always been one nagging mystery: The relationship cannot be recreated in a lab. Lichens can be found in all sorts of ecosystems, but no matter what you do with the fungus and the alga, you cannot get them to form the same relationship in a laboratory setting. A recent study might explain why. The authors of the study analyzed two different species of lichen, Bryoria fremontii and Bryoria tortuosa. They are easily distinguished from each other, since the first is dark brown, while the second is yellow. However, recent studies have indicated that the fungus and alga in each are the same. How is it that two lichens can be so different when their fungus and alga are the same? That’s what the authors wanted to find out.
They decided to look at the specific genes that were actually being used by the two species. After all, even if both lichens have the same fungus DNA and the same alga DNA, it’s possible that one lichen uses one set of genes more than the other lichen, and perhaps that could explain the differences between them. However, their initial analysis indicated that both lichens used essentially the same set of genes. That’s when they decided to think “outside the box.”
When doing a study like this, you have to decide what gene products you are looking for. They had limited themselves to the genes found in the fungus and the alga that were known to exist in the lichens. They decided to change their analysis to include all known fungus genes. When they did that, they found that genes from an entirely different fungus were also being used by the lichens! That fungus is a type of yeast (specifically from genus Cyphobasidium), which is very different from the fungus that was already known. The authors did some very difficult microscope work and confirmed the presence of the yeast in the lichen. In addition, they did the same genetic tests on many different species of lichen, and they found the yeast genes in the vast majority of the lichens that they studied. As a result, the authors suggest that the vast majority of lichens are made up of at least three different species. Here is how they conclude their paper:
The assumption that stratified lichens are constructed by a single fungus with differentiated cell types is so central to the definition of the lichen symbiosis that it has been codified into lichen nomenclature. This definition has brought order to the field but may also have constrained it by forcing untested assumptions about the true nature of the symbiosis. We suggest that the discovery of Cyphobasidium yeasts should change expectations about the potential diversity and ubiquity of organisms involved in one of the oldest known and most recognizable symbioses in science.
While this discovery in and of itself is remarkable, it is also an excellent illustration of how assumptions can put blinders on science. Why haven’t these yeasts been discovered in more than 140 years of lichen study? Partly, because they are well-hidden. To confirm the presence of the yeast in the lichen required some rather detailed microscopic analysis. In addition, when you are doing genetic analysis, you have to decide what to search for, which means your results will be limited by that decision. However, here’s the main reason: No one was looking for them. Since the assumption that lichens are mutualistic symbioses between two different species was so ingrained in biological thought, no one ever considered looking for a third, until these authors decided to “think outside the box.”
I wonder how many more scientific discoveries are waiting on other scientists who are willing question old paradigms and look for things that no one else has been looking for!
I am putting the finishing touches on my 7th/8th grade book Science in the Atomic Age (which should be available for purchase in June), and I wanted to post another excerpt from the book. The excerpt I posted previously comes from a section about the brain. This one comes from an earlier chapter, where I discuss plants.
By the time the students reach this point in the course, they know that producers are organisms which make their own food (usually through photosynthesis), and consumers must eat other organisms for food. They also know how to interpret chemical equations and the specific chemical equation for photosynthesis. In addition, I have just shown them the chemical equation for the process by which consumers burn their food for energy and have pointed out that it is the opposite of the chemical equation for photosynthesis. Here is the discussion that follows:
In other words, producers like plants use water and carbon dioxide to make glucose and oxygen, and consumers then use that glucose and oxygen to make carbon dioxide and water. So producers are feeding us, and we take what the producers make and then produce the chemicals they need to make what we need! In this sense, at least, consumers are the opposites of producers.
This is a real testimony to God’s power and ingenuity. He not only created the producers to feed the consumers, He also designed the consumers so that when they use what the producers made, they give the producers what is needed so that the producers can make more food. Now, of course, the sun plays its role, too. It provides the energy the producers need in order to do photosynthesis in the first place.
This is all summed up in the illustration above. The sun shines light on the earth. Producers absorb that light in the chloroplasts of their cells and use it, along with carbon dioxide and water, to make glucose and oxygen. Consumers then take that glucose and oxygen and use them to make energy for themselves. This ends up making carbon dioxide and water, which can be used by the chloroplasts in the producers (along with more energy from the sun) to make more glucose and oxygen. As a result, the only constant input needed is energy from the sun. Everything else just keeps getting recycled between producers and consumers!
This Balance Is Even More Amazing
The balance between producers and consumers, as illustrated in the drawing above, is amazing. However, we need to be aware that it is often oversimplified. I have heard many educators say, “Plants make food and oxygen, while animals use food and oxygen.” That is true, but it is oversimplified. Plants do make food and oxygen. It happens when they are doing photosynthesis. However, they also use food and oxygen.
Does that statement surprise you? It might, but if you think about it, the statement makes a lot of sense. After all, why are plants doing photosynthesis? Because they need to make food for themselves, right? Well, what does the plant do with that food? It burns that food for energy, according to the equation I showed you earlier. What does that equation say? It says oxygen and C6H12O6 are reactants. That means they are used up. So plants not only use carbon dioxide and water to make glucose and oxygen, but when it is time for them to burn their food, they must use glucose and oxygen to make carbon dioxide and water.
Now wait a minute. If plants end up using the glucose and oxygen they make through photosynthesis, how are we able to use it? Because of this important fact: Plants make a lot more food and oxygen than they ever need. If plants only made the food that they need, they would end up using it and all the oxygen they made, and there would be nothing for consumers to eat or breathe. However, plants have been designed to make much more food than they will ever need. That means they also make more oxygen than they will ever use. That way, there is food and oxygen for consumers.
This is a very, very important design feature that many people don’t appreciate. In order for us (and most consumers) to survive, it’s not enough that producers like plants exist. They must not only exist, but they must do a lot more work than just keeping themselves alive. They must overproduce food and oxygen so that there is plenty for the consumers. Thus, the proper way to describe the balance between plants and animals is, “Plants make food and oxygen, but they also use it. However, they make more food and oxygen than they need, so that animals can use the rest.”
It always troubles me when I read other scientists who ignore the data in order to cling to their cherished dogmas. As a scientist, I know that this holds back the progress of science. As a result, I was heartened to read three scientist calling on their colleagues to abandon evolutionary dogma when it comes to pseudogenes. If others heed their call, we will most certainly learn more about DNA.
A pseudogene is a nonfunctional genomic region that originated by duplication of, and is still homologous to, an ancestral gene.
In other words, a pseudogene is the result of a gene being copied and then broken. Creationists have long argued that pseudogenes are functional; they just don’t function the way evolutionists expect them to. The three authors of the paper I mentioned above have arrived at that same conclusion (at least for many pseudogenes), and they are asking their colleagues to pay attention to the data and do the same.
To emphasize the point that this evolution-inspired dogma is wrong, they list many pseudogenes that have been demonstrated to have an important function. They then make this important statement:
The examples of pseudogene function elaborated on here should not imply that pseudogene functionality is likely to be confined to isolated instances.
In other words, you can’t say that the known functional pseudogenes are exceptions to the rule. There are enough functional pseudogenes to call into question the assumption that they are mostly non-functional.
At the same time, however, these authors are cautious:
The purpose of this article is not to discard the pseudogene concept or to suggest that all pseudogenes are functional. The majority of currently annotated pseudogenes are neither robustly transcribed nor translated. Such regions fit well the original descriptions of pseudogenes as ‘similar, but defective’. Rather, we argue that their labelling as pseudogenes is not constructive for advancement of understanding of genome function and misdirects experimental design.
In other words, the authors are simply telling their colleagues to follow the data. Do not assume that a pseudogene is non-functional just because it has been identified as a pseudogene. Instead, investigate it to find out whether or not it actually is. The progress of science is hindered when you assume non-functionality because of the way the sequence has been identified.
I not only completely agree with that sentiment, I would also add this: following any dogma (evolutionist, creationist, or other) hinders the progress of science. Scientists should be willing to follow the data wherever they lead. Unfortunately, such scientists tend to be the exception, not the rule.
In my elementary science book, Science in the Beginning, I explain to students that many things in science are counter-intuitive. To make this point clear, I have them do an experiment with unexpected results. In one lesson, students learn that salt melts ice. In the next lesson, they are presented with this question:
In which situation will an ice cube melt more quickly:
Floating in hot freshwater or floating in hot saltwater?
I then have them do the experiment. They put hot freshwater into two glasses. They then add salt to the water in one of the glasses. Afterwards, they put ice cubes of roughly the same size in each. Unlike most people expect, the ice cube in freshwater melts more quickly. Here is how I explain the results (keep in mind they have already seen that freshwater floats on saltwater):
So, why did the experiment produce counter-intuitive results? Because of another fact that you know but probably didn’t think was important enough to consider: freshwater floats on saltwater. Why did the ice cubes melt so quickly? Because you put them in hot water. The water was so hot that the ice cubes had to melt. But when the ice cubes melted, where did the water that was formed by the melting actually go?
Let’s start with the freshwater. Remember that cold freshwater is just a bit heavier than an equal volume of warm freshwater. What does that tell you? It tells you that cold freshwater sinks in warm freshwater. Well, as the ice cube melted, the water that was formed by the melting process was still pretty cold. Thus, it sank in the hot water, getting out of the way. This allowed the warm freshwater around the ice cube to stay very warm, which kept melting the ice cube.
What happened in the saltwater was a completely different story, however. Remember that freshwater floats on saltwater. This effect is so strong that cold freshwater floats in hot saltwater. So,in the end, when the ice cube started to melt, the cold freshwater that was formed from the melting ice cube floated on the top of the saltwater, along with the ice. It didn’t sink like it did in the cup that had freshwater in it. For the ice cube to continue to melt, then, the hot saltwater had to heat up the newly formed freshwater that floated on the surface. That took time, and as a result, the ice cube melted a bit more slowly.
So, the counter-intuitive results were caused by the fact that freshwater floats on saltwater, but cold freshwater sinks in hot freshwater. That probably wasn’t something you thought about when I initially asked you the question, but you probably understand why it is important now that I have explained it to you. It turns out that a lot of science is like this because God created an incredibly complicated world for us. Often, we don’t think about all the different things that are important when we try to analyze a situation. As a result, many experiments end up showing us counter-intuitive results. Regardless of how counter-intuitive, however, as a scientist, you must follow what the experiments show. After all, we can’t always take into account all the complexities of creation, so when we do an experiment and find counter-intuitive results, unless we find something wrong with the way we did the experiment, the results are more important than what we think the results should be!
A homeschooling mother, Leah, recently shared a variation that she and her son, Parker, made to this experiment, and it is pictured above. They made ice cubes out of water that had blue food coloring in it. The first picture on the left is of the ice cube in freshwater. You can clearly see the cold water from the melted ice cube sinking in the warm freshwater. The middle picture shows you both ice cubes, and it is really clear that the water coming from the melting ice cube is floating on the saltwater, while it is mixing well with the freshwater. The last picture shows you what is left after both ice cubes melt. Once again, you can see that the water from the ice cube has mostly stayed floating on the saltwater.
The impressive thing about this variation is that Leah came up with the idea on her own. When she suggested it to Parker, he immediately understood what it would show. I would have never thought to do this kind of variation, but it really illustrates the process well. I will probably add a note about doing this in the next printing of the course so that others can benefit from it.
I have been teaching science for 34 years. I have been writing science textbooks for 27 years. I can’t tell you how many times I have written about blood and its components. Indeed, I am writing a 7th-grade textbook right now (Science in the Atomic Age), and it has a couple of sections on the properties and characteristics of human blood. As usual, I discuss the cellular components of blood (red blood cells, white blood cells, and blood platelets) as well as the chemical components of blood (blood clotting factors, water, electrolytes, various proteins, etc.). I honestly thought we understood blood pretty well. However, God’s creation is so complex and intricate, it still surprises us. In a recently-published paper, scientists have found that blood contains something no one ever noticed before, and it is neither cellular nor chemical. It is something in between!
To understand what was found, you need to know that cells in fungi, plants, animals, and people contain small structures that are responsible for burning chemicals from your food and packaging the resulting energy into small units that the cells can use. Those structures are called mitochondria. While most of a cell’s DNA is held in the nucleus of the cell, there is some DNA found in the mitochondria. Not surprisingly, it is called mitochondrial DNA (mtDNA) to distinguish it from the DNA found in the nucleus, which is called nuclear DNA (nDNA).
I had learned quite some time ago that there was a lot more mtDNA in blood than nDNA, but that always made sense to me. Red blood cells have neither, because they eject their nucleus and mitochondria when they mature. However, white blood cells have both. When someone extracts DNA from blood, he or she is getting the nuclear DNA from the white blood cells. Well, each cell has several mitochondria and only one nucleus, so the white blood cells will contribute more mtDNA than nDNA to blood. In addition, blood platelets have mitochondria but no nucleus, so they are contributing a lot of mtDNA and no nDNA.
I have been working on my new book, Science in the Atomic Age, which (Lord willing) will be published this summer. In the section where I cover the nervous system, I compare a mouse brain and a human brain to computers. It’s rather fascinating. Below, you will find a slightly-edited excerpt from that discussion. Please note that the students have already learned that neurons are cells found in nervous tissue and that the integumentary system is the system of organs that makes your skin:
The brain has three major divisions: the cerebrum (suh ree’ brum), the cerebellum (sehr’ uh bell’ uhm), and the brain stem. The cerebrum is in charge of most of the really complicated things that the brain does. For example, it receives signals from your eyes and interprets them so that you can see. It receives signals from your ears and interprets them so you can hear. It receives signals from all the nervous tissue in your integumentary system so that you can figure out what you are touching as well as things like whether you are too warm, too cold, or comfortable. It also helps you learn, and it stores your memories. All this takes a lot of work, so it requires a lot of neurons.
How many neurons? The average adult cerebrum contains about 20 billion neurons. That number doesn’t mean very much by itself, so by comparison, the average adult mouse cerebrum contains about 2.5 million neurons. So the human cerebrum contains about 10,000 times as many neurons as a mouse’s cerebrum. Of course, a mouse is much smaller than a person. By weight, a person is about 3,000 times as heavy as a mouse. At least part of the difference between a mouse’s cerebrum and a person’s cerebrum is due to that. But people are much more intelligent than mice, and the number of neurons in the cerebrum must also be related to that.
If you haven’t seen it, there is a viral story about a high school student, Wolf Cukier, who made a significant discovery. During a summer internship, he was looking through data that had already been flagged as coming from binary star systems. In these systems, two stars orbit one another. While this may sound unusual, most stars in the universe (as far as we can tell, anyway) are a part of a system in which two or more stars orbit one another. Solitary stars like our sun are the exception, not the rule.
In most binary star systems, one star is much brighter than the other. As a result, if earth’s orbit is aligned with the orbital paths of the two stars in a binary star system, when the dimmer star passes between earth and the brighter star, the light we get from that star system gets dimmer. This is called an eclipsing binary. The data that Wolf Cukier was studying had already been noted as representing eclipsing binaries, but Wolf noticed another periodic dimming in the light coming from a binary star system charmingly named “TOI 1338.” The dimming was weaker than the dimming seen from the eclipsing binary, but it was regular. It was determined that this weak dimming was the result of a planet coming between earth and the brighter star in the binary system. In other words, this young man had found a planet orbiting two stars! Such planets are rare, but not unheard of. There were seven such planets confirmed before this one, but this is the first one discovered using this particular telescope, which is called TESS.
If you can’t quite visualize what is going on here, NASA has made a helpful animation, which I have included below. As you can see from the animation, when the dimmer star in the system passes between earth and the brighter star, the amount of light earth receives from the system decreases a lot. When the planet comes between earth and the brighter star, it dims a little.