June 2014 : Proslogion

Even More on Slime Molds

A slime mold chooses the shortest path to the food (labelled "AG") in a maze. (Image is from the article being discussed.) — A slime mold chooses the shortest path to the food (labelled “AG”) in a maze.
(Image is from the article being discussed.)

I recently ran across a 14-year-old study that I found incredibly interesting. I normally discuss studies that have occurred in the past few years on this blog, but since this study goes well with two other blog posts I have written (here and here), I thought I would go ahead and write about this one as well. In the experiment, the authors studied a slime mold (Physarum polycephalum) that was in its plasmodium stage. During this stage of its life, it is a huge, single cell that has thousands of nuclei.

The researchers grew the slime mold on a maze (as shown on the far left of the image above). Once it had covered the maze, they put out some food in the form of nutrient-rich agar (labelled “AG” in the image above). They put one source of food at the beginning of the maze and another source of food at the end. There were four paths through the maze that connected the two food sources. In a mere four hours, the slime mold had built connections between the two sources using all four of the paths (as shown in the middle of the image above). However, in another four hours, it had worked out the shortest of the four routes (as shown on the right of the image above), and that’s the only one it maintained.

Now as I pointed out in my other two posts about slime molds, these organisms are thought to be “primitive,” because they are thought to have evolved long ago, even before plants and animal evolved. Nevertheless, when presented with puzzles, they are able to solve them. In fact, in one of the previous studies I wrote about, it was suggested that these “primitive” organisms could help us design better networks. Based on the results of this study, such networks would probably be very efficient.

In my high-school biology course, I stress over and over again that there is no such thing as a “simple” organism. The more we study nature, the more clear that becomes.

Yet Another Failed Evolutionary Prediction

This a colony of coral from the genus Acropora, the same genus analyzed in the study that is being discussed. (click for credit)

One of the main ways to test the validity of a scientific hypothesis is to use that hypothesis to make predictions. If those predictions are confirmed by the data, more weight is added to the validity of the hypothesis. If those predictions are falsified by the data, the validity of the hypothesis should be called into question. When it comes to the hypothesis of evolution (in the flagellate-to-philosopher sense), prediction after prediction has been falsified (see here, here, here, here, and here, for example). A recent study published in the Proceedings of the National Academy of Sciences adds to the very long list of failed evolutionary predictions.

In this case, the researchers were studying the phenomenon of apoptosis, which is programmed cell death. In an organism that is composed of several cells, it is important to have a mechanism by which cells that are diseased, very old, or otherwise unstable can be removed. That way, they won’t harm the rest of the organism. This is one of the purposes of apoptosis. When a cell recognizes that it is a potential threat to the organism as a whole, it can actually release protein-destroying chemicals that cause it to kill itself.

Not surprisingly, the process by which apoptosis occurs is incredibly complex. Nevertheless, scientists have made a lot of progress in understanding it. We now know that there are specialized enzymes that start the process. They belong to a group called the TNF receptor-ligand superfamily. In this superfamily, there are TNF ligands (collectively called TNFSF) and receptors (collectively called TNFRSF). When the ligands bind to the receptors, a process starts that can either cause the cell to override its programmed cell death or continue on with it, depending on other chemical signals that are taking place within the organism.

Now don’t get lost in the terminology here. The idea is that multicelled organisms must have a way to get rid of cells that might be bad for the organism as a whole. One way this happens is for special chemicals from a group called TNFSF to bind to other special chemicals from a group called TNFRSF. This activates a process that determines whether the cell should continue to be a part of the organism or kill itself for the good of the organism.

The researchers who published this study decided to analyze apoptosis in one of the more “primitive” organisms on the planet, a species of coral called Acropora digitfera. According to the researchers, corals like this species have been around for 550 million years, so it should be a good representative of some of the earliest animals that ever existed on the planet. Given that assumption, the researchers thought that the apoptosis process in corals should be rather simple – at least a lot less complicated than what we see in the “higher” animals such as flies, birds, and people. Surprisingly, they found the exact opposite.

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A Father’s Day Drama

This past Sunday was Father’s Day. I was traveling home from the California Homeschool Convention, so I wasn’t able to attend the church I regularly attend. However, I did put together a drama that was performed to honor the fathers who came to church that day. My “go to” actor in the drama team took responsibility for it, and everyone says that it went really well.

I want to add one note about how you might stage this to make it even more enjoyable. The drama is about how a son’s perception of his father changes as he grows up. To illustrate each perception, I took pictures of men in our congregation and had them projected onto the big screen. I did this to make the drama as simple as possible, since I wasn’t there to deal with all the headaches. However, I think the drama could be even better if you used different actors to represent the different perceptions. This would make for a larger cast and a lot of costuming issues, but I do think it would be more interesting and more fun for the congregation.

As is the case with all my dramas, please feel free to use this script in any way that serves the Body of Christ. I would appreciate credit, but that’s not necessary.

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The California Homeschool Convention

This is the Ontario Convention Center, where the California Homeschool Conference was held. (click for credit) — This is the Ontario Convention Center, where the California Homeschool Conference was held.
(click for credit)

This past weekend, I spoke at the California Homeschool convention in Ontario, California. It is a part of the Great Homeschool Conventions series, and as such, it offered a wide range of speakers as well as a big exhibit hall in which homeschoolers could examine the many great resources that are available to them. It was the first year for this particular convention, and that usually means a fairly small crowd. It generally takes a while for a homeschooling convention to get established, so you don’t expect large crowds in the first few years of a conference. This first-year conference defied that trend. It attracted a big crowd, and I was pleasantly surprised.

I gave five talks at the convention, two of them with Diana Waring. My “solo” talks were Recent News in Creation Science, The Bible: A Great Source of Modern Science, and Teaching Elementary Science Using History as a Guide. The talks I did with Diana Waring were I Didn’t See That Coming and Arguing to Learn. The talks were well attended, and the audience members were actively engaged.

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How Do You Design the Best Train? Copy the Designs of the Ultimate Engineer.

This is an Azure Kingfisher. The Shinkansen "bullet train" in Japan was improved by copying the design of a kingfisher's beak. (click for credit) — This is an Azure Kingfisher. The Shinkansen “bullet train” in Japan was improved by copying the design of a kingfisher’s beak. (click for credit)

I ran across a story on biomimicry a few days ago. Although it discusses things that happened a while ago, I thought it was a great example of how copying designs found in nature can improve the designs produced by modern science and technology. The story involves Eiji Nakatsu, a Japanese engineer who worked on the high-speed “bullet” trains in Japan. These trains travel at speeds approaching 200 miles per hour, and not surprisingly, there are a lot of design challenges involved in such systems.

In particular, there were three design issues that plagued the trains. First, the train would produce a very loud noise when entering a tunnel, because it would be “smashing” into a column of confined air. While this slowed down the train a bit, the big problem was the noise that it produced. The loud bang would disturb not only wildlife but also nearby residents. In order to comply with Japanese noise pollution regulations, something needed to be done.

According to the article, Nakatsu met this challenge by redesigning the front of the train. As a bird-watcher, he had observed Kingfisher birds diving into water without producing much of a splash. He realized that this was similar to what the trains had to do when entering a tunnel, so he designed the front of the train to be more like the head and beak of a kingfisher. It worked. The train could enter tunnels at full speed without producing a loud noise.

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The Homeschoolers of Wyoming Convention

This is one of the signs that welcomes people to Wyoming. (click for credit)

This past weekend, I spoke at the Homeschoolers of Wyoming convention in Sheridan, Wyoming. I had never been to that part of the state before, so not only did I have a great time at the convention, I enjoyed visiting a new location. I gave four talks at the convention: Why Homeschool Through High School, Homeschooling: The Solution to our Education Problem, “Teaching” High School At Home, and Teaching Critical Thinking. In addition, I got to speak with several homeschoolers while I was hanging out at my publisher’s booth in the exhibit hall.

During one of those times, I experienced something that probably doesn’t happen very often outside of homeschooling circles. I was speaking with a mother about her teenage daughter’s options when it comes to science. The daughter was there as well. She wanted to be a forensic anthropologist, and the mother wanted to know what sciences her daughter should be taking in high school. I told her that the three subjects she should definitely take are biology, chemistry, and human anatomy, because they would all have a direct bearing on forensic anthropology. As a result, they would give her a good idea of the kind of science she would be doing if she chose that field. She should also strive to take physics, but it would not have as much direct bearing on her field as the other three.

Since the daughter had not taken any of those subjects yet, I suggested that she should start with biology. She began looking at my biology text and mentioned a few things she liked about it. She then asked me some questions regarding specific aspects of the course. Then she asked me the following question:

My main concern is, will this book challenge me enough?

I have to tell you, that’s a question you rarely hear from a teenager when it comes to a textbook! Nevertheless, it isn’t the first time I have been asked that question by a high school student at a homeschool convention. That’s one of the many reasons I love working with homeschooled students! They understand that education is important, and many of them actually want to be challenged by it!

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“Global Warming” Has Not Increased Droughts

The dry portion of a riverbed in California (public domain image)

One of the common predictions made by people who believe in catastrophic global warming (aka “climate change”) is that as the globe’s temperature rises, there will be more and more droughts. As one book on global warming puts it:¹

Extreme drought is one of the expected consequences of increased global warming, especially in the American Southwest, where it has already been projected to be severe by several models.

I have already written about the fact that actual observations show the precise opposite for the American Southwest. But what about the globe as a whole? Perhaps the American Southwest is not behaving as global warming enthusiasts predicted, but that doesn’t mean droughts aren’t increasing in other parts of the world. Surely the global warming that has already happened has produced drier conditions on the earth as a whole, right? After all, that’s what the climate modelers have predicted.

For example, the British government funded a study on global warming and drought by climatologists at the Hadley Centre for Climate Prediction and Research. The study, which was published in 2006, made the following prediction:²

This graph represents one climate model's predictions of the percentage of land around the world that will experience drought. The dotted lines are for moderate drought, the dark, solid lines are for severe drought, and the light, solid lines are for extreme drought. There are three lines for each level of drought because the model was run using three different sets of assumptions. (image from reference 2) — This graph represents one climate model’s predictions of the percentage of land around the world that will experience drought. The dotted lines are for moderate drought, the dark, solid lines are for severe drought, and the light, solid lines are for extreme drought. There are three lines for each level of drought because the model was run using three different sets of assumptions.
(image from reference 2)

Notice that the amount of land around the globe which experiences moderate to extreme drought was projected to increase in a shaky but consistent fashion throughout the 21^st century. Is that what’s actually happening?

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Not Suprisingly, DNA Is Even More Complex Than Previously Thought

Because proteins are so complex, they need to be viewed in different ways. This illustration shows three of the ways a protein can be viewed by chemists. (click for credit) — Because proteins are so complex, they need to be viewed in different ways. This illustration shows three of the ways ways a protein can be viewed by chemists. (click for credit)

DNA is an incredibly complex molecule that can store information in an amazingly efficient manner. Experiments indicate that a single gram of DNA (a gram is approximately the mass of a U.S. dollar bill) can store 500,000 CDs worth of information! It uses a complicated system of alternative splicing so that a single region of the molecule can store the information needed to produce many different chemicals (see here and here, for example). It is so complex that even the best chemistry lab in the world cannot produce a useful version of it. In the end, the best human science can do is make tiny sections of DNA and then employ yeast cells to stitch those segments together so that they become something useful.

Over the past few years, DNA has surprised scientists with higher and higher levels of complexity. For example, scientists recently learned that DNA can store an extra level of information by slightly altering its typical shape. This was particularly surprising, because the fact that DNA alters its typical shape from time to time was already known. However, the alteration was thought to be the result of some kind of damage. We now know that it is not the result of damage. In fact, it is another level of complexity.

Even more recently, scientists discovered that DNA sometimes stores two completely different types of information in the same place. In some sections, it stores the recipe for making a chemical in the same place that it stores information regarding how often that chemical needs to be made. Once again, this was a complete surprise, because it was thought that the recipes for making chemicals were stored in certain sections of DNA, while the information regarding how often those chemicals should be made was stored in completely different sections. However, we now know that at least in some cases, both kinds of information are stored in the same place!

Well, DNA has offered up another surprise to geneticists, and it points to yet another level of sophistication in this incredible molecule.

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