June 2018 : Proslogion

Study of Mice Highlights the “Junk DNA” Myth

Junk DNA is a crucial to evolutionary theory, despite the fact that it most likely doesn’t exist to any significant extent.

The concept of “junk DNA” is crucial to evolutionary theory. For example, the “gold standard” of evolutionary simulations doesn’t produce any evolution unless at least 85% of the simulated DNA is junk. This is why so many evolutionists are fighting against the straightforward conclusions of the ENCODE series of studies, which indicate that at least 80% of the human genome is functional. Dr. Dan Graur, for example, has famously said that if ENCODE is right, then evolution is wrong.

As is the case with most evolution-inspired ideas, the more we learn about the natural world, the more it becomes obvious that there is very little “junk DNA” in nature. A recently-published study of gender in mice highlights this fact. In the study, an international collaboration of scientists examined the development of sexual characteristics in mice. As you probably already know, in mammals there is a pair of chromosomes referred to as sex chromosomes. If an individual has an X chromosome and a Y chromosome in that pair, he is a male. If the individual has two X chromosomes, she is a female.

But the development of the proper characteristics associated with each sex depends on what happens during embryonic development. For example, as a mammal embryo develops, it starts out producing ovaries. However, there is a gene on the Y chromosome called Sry. It produces a protein that controls the production of another protein, called SOX9. The SOX9 protein turns developing ovaries into testes. A male develops testes, then, because of the action of a gene on the Y chromosome. But as this latest study shows, there is more to it than that.

The scientists removed a small section of DNA from genetically-male mice. This section is found in what the authors refer to as a “gene desert,” a section of DNA that is devoid of genes. Nevertheless, when that small section of DNA was deleted, the genetically-male mice developed ovaries and female genitalia. Now please understand that the genes involved in the production and regulation of the SOX9 protein were not removed; only a small portion of what many would call “junk DNA” was removed. Nevertheless, without that section of DNA, the genetically-male mice did not produce enough SOX9 protein, so the ovaries continued to develop into ovaries, which then caused the production of female genitalia. As a result, the authors refer to this small section of DNA as a SOX9 “enhancer.” It enhances the production of SOX9 at just the right time, so the males develop the correct gender characteristics.

While the results of this study are fascinating, they are not surprising. After all, it has become more and more clear that the concept of “junk DNA” is a myth. As a result, it makes sense that even small sections of DNA have important functions, at least in certain stages of development or under certain conditions. The reason I am blogging about the study is because of something the lead author said in an article that was published on his institution’s website:

Our study also highlights the important role of what some still refer to as ‘junk’ DNA, which makes up 98% of our genome. If a single enhancer can have this impact on sex determination, other non-coding regions might have similarly drastic effects. For decades, researchers have looked for genes that cause disorders of sex development but we haven’t been able to find the genetic cause for over half of them. Our latest study suggests that many answers could lie in the non-coding regions, which we will now investigate further.

Indeed. As Dr. John Mattick so aptly put it more than a decade ago:

…the failure to recognise the implications of the non-coding DNA will go down as the biggest mistake in the history of molecular biology.

Observations about Second-Generation Homeschoolers

One of several second-generation homeschoolers I have met this year.

This is “convention season” for homeschoolers across the United States, so I have been traveling to several different homeschool conventions, giving talks and speaking individually with lots of homeschooling parents. In some ways, these conventions never change. Many of the talks that I give are on the same topics that I spoke about at homeschooling conventions more than 20 years ago: how to “teach” science at home, why it is best for most students to be homeschooled through high school, and the fact that homeschooling produces graduates who are, on average, significantly better university students. Obviously, the details of the talks change every few years, but the basic points do not.

In the same way, many of the questions I get from homeschoolers are the same year after year and convention after convention. My son is only in 7th grade but is about to start Algebra 1. Should he really take high school biology? (In general, the answer is “yes,” but it depends on the student’s ability to work independently and how he reacts to academic rigor.) If he does take biology in 7th grade, can it be included on the high school transcript? (Once again, the answer is “yes.” See this article for more details.) My daughter is very talented in ballet and wants to pursue it as a career, but it requires a lot of rehearsal time. What should I do? (If a professional says that she has real potential, then you should scale back her other academic courses so that she can pursue her talents. Don’t neglect her education; just pare it down to the basic essentials so that she can have more time to hone her craft).

At the same time, however, each year brings a few changes. Some of the conventions that used to be large and well-attended are either very small or nonexistent. Other conventions that didn’t exist many years ago are now large and well-attended. Lots of new curricula are available, giving homeschoolers a wealth of choices for how to meet their children’s educational needs. The people you see at homeschooling conventions are also becoming more and more diverse every year.

This year, I noticed a new difference. Most likely, the difference has been slowly growing over a period of many years, but after speaking at the California Homeschool Convention this past weekend, it struck me that this year, I have interacted with a lot of second-generation homeschoolers (homeschool graduates who are now homeschooling their own children).

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Another Unsuccessful Attempt to Detect Dark Matter

This NASA image illustrates the fact that most astrophysicists think there is about four times as much dark matter as visible matter in the universe.

A couple of months ago, I wrote an article about a galaxy that has no “need” for dark matter. This is interesting, because most galaxies “need” dark matter to explain the motion of their stars. Based on the mass that is actually observed in most galaxies, the stars should not be moving the way that they do. Thus, scientists think there must be a lot of mass in those galaxies that cannot be seen (dark matter). To make their current theories work, scientists estimate that about 80-85% of the mass in the universe comes from dark matter. Since dark matter is thought to be so prevalent in the universe, scientists have tried to detect it directly, without any luck.

How do you detect something you can’t see? First, you have to have some idea of what you are looking for. Then, you design an experiment to see if what you think you might be looking for really exists. The most “promising” candidate for dark matter is a class of hypothetical particles called “weakly interacting massive particles” (WIMPs). These are particles that don’t interact with matter using the electromagnetic force. Since the electromagnetic force works via the exchange of photons, if a particle doesn’t use the electromagnetic force, it produces no light. Instead, WIMPs are thought to use only the gravitational force and the weak force, which works only at the subatomic level and is responsible for most of the natural radioactivity on planet earth.

Since all the matter we know of uses the electromagnetic force, WIMPs are obviously strange particles. However, they are allowed by the mathematics of the standard model of physics, which is why they are considered the most “promising” of the candidates for dark matter. How do scientist try to detect WIMPs? The most sensitive WIMP detector is called XENON1T, which is filled with liquid and gaseous xenon. The design of the detector allows scientists to identify electromagnetic interactions that occur between particles hitting the detector and the liquid xenon inside. They discard those interactions, and what’s left should be any interactions that use only the weak force. Those, of course, would be caused by the WIMPs.

The team of scientists using XENON1T reported their latest results at a seminar on May 28th, and so far, they have not seen a signal that is consistent with what is expected for WIMPs. I think their results argue strongly that WIMPs don’t exist, but that’s not the only explanation. The results could also mean that physicists don’t understand WIMPs as well as they thought, and these particles actually interact more weakly with matter than what the theories tell us.

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NASA Has NOT Found the Building Blocks of Life on Mars

A “self-portrait” of the Curiosity rover on Mars: a composite of several images taken with the rover’s Hand Lens Imager.

The headlines are screaming it. NASA Mars rover discovers ‘building blocks’ for life: 3-billion-year-old organic matter, Curiosity Rover Finds Ancient ‘Building Blocks for Life’ on Mars, Building Blocks of Life Found on Mars, etc. etc. There’s only one problem. The building blocks of life were not found on Mars. I wish they had been. I think it would be awesome to find evidence of life on other planets besides earth. However, what NASA’s rover discovered on Mars wasn’t even close to the building blocks of life.

So what was really found on Mars? Not surprisingly, the title of the scientific paper that was published in the journal Science comes close to the truth:

Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars

Now, of course, I think the “3-billion-year-old mudstones” is scientifically irresponsible, but notice the difference between the scientific article’s title and the title of the articles written by “science journalists.” There is no mention of life in title of the scientific article.

But wait a minute. Isn’t that just semantics? Doesn’t “organic” refer to chemicals that come from living things. Absolutely not! As I tell students in my elementary science book Science in the Industrial Age:

While organic chemicals are generally associated with living things, it is possible to make them from nonliving things…Scientists still use the terms “organic” and “inorganic” today to classify chemicals, but they do so based on the elements that make them up, not based on where they come from.

Now, of course, the news articles I linked above eventually get around to saying that it is possible for the molecules discovered on Mars to have come about without the presence of life. Even with that caveat, however, the news articles are still wrong, because the molecules discovered are not, in any way, the “building blocks of life.”

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Study Demonstrates that Most Animal Species Came Into Existence at the Same Time?

Most of an animal’s DNA is in the nucleus of the cell, but there is DNA in the powerhouse of the cell, which is called the mitochondrion.

In a comment on a previous article, a reader informed me of a study that I had not seen. It was published in the journal Human Evolution and its results are consistent with the idea that 90% of all animal species came into being at roughly the same time. This is certainly not what the hypothesis of evolution would predict, so some creationists as well as some intelligent design advocates have presented the study as evidence against evolution. In my reply to the comment, I expressed skepticism, even though I would love for the conclusions of the study to be correct. Now that I have read the study itself, I am even more skeptical.

The authors of the study analyzed the DNA of many different species of animals. However, they did not look at the DNA found in the nucleus of the cell. That DNA, called nuclear DNA, is responsible for most of an organism’s genetically-defined traits. They looked at mitochondrial DNA, which is the small amount of DNA that is found in the mitochondrion, the structure that produces most of the energy that the cell ends up using. To give you an idea of how different mitochondrial DNA is from nuclear DNA, the nuclear DNA of a human being is over 3 billion base pairs long, while human mitochondrial DNA is just over 16,000 base pairs long. You don’t need to know what “base pairs” are to see that there is only a tiny, tiny amount of mitochondrial DNA in a human cell compared to nuclear DNA.

Now even though there isn’t a lot of mitochondrial DNA, some sections of it seem to be very characteristic of the species of animal from which the cell comes. For example, a 2016 study analyzed a section of mitochondrial DNA (called the COX1 gene) among different species of birds. It showed that the COX1 gene alone was enough to separate 94% of the birds into species. Similar studies indicate that the COX1 gene can separate other species of animals, so the sequence of the COX1 gene is often referred to as the DNA barcode of the animal. This is what the authors of the study I am discussing focused on.

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