Category: Answered Questions

What Is the Function of a Narwhal’s Tusk?

Three Narwhals swimming close to the surface of the ocean. The lead narwhal’s tusk is easy to see.
(credit: Dr. Kristin Laidre, Polar Science Center, UW NOAA/OAR/OER)

Back in April, I spoke at the Ohio Homeschool Convention. It is part of the Great Homeschool Conventions, at which I have been fortunate to be a regular speaker. This year, the convention graciously allowed me to do my favorite kind of presentation: A Question/Answer Session. I have done them at other conventions (see here, here, and here), and I always enjoy them, usually because I learn something. I open these sessions by simply asking for questions, and I tell the audience that the questions can be about anything. If I can’t answer a question, I am happy say the three words any scientist should be totally comfortable saying, “I don’t know.” I also tell them that if I have to say those words, I will try to find the answer later and post it on my blog.

That’s what happened at the Ohio Homeschool convention. One of the audience members asked me what a narwhal (Monodon monoceros) does with its horn. I had to tell him that I don’t know. I did tell him that it isn’t really a horn. In fact, it is an elongated tooth. I speculated about a couple of possibilities, but I couldn’t say anything for sure. That was a few weeks ago, and I have been pretty busy since then. However, I have wrapped up both the Thermodynamics course I was teaching at Anderson University, and the online classes I have been teaching this year, so I finally got around to investigating narwhals.

The short answer is that we still don’t know what a narwhal does with its tusk. The long answer, however, is much more interesting.

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No, Scientists Did Not “Partially Revive” Pig Brains!

One conception of a pig’s brain being kept alive outside the body. (modified from the linked image)
As anyone who reads my blog knows, I have a rather low opinion of science “journalism.” In my experience, most science “journalists” know little about journalism and even less about science. As a result, what they publish is often so misleading that it just adds to the level of scientific ignorance that is already shockingly prevalent in today’s society.

As a result, I was pleased to find that two different readers sent me two different articles about a recent experiment involving dead pig brains. They were both justifiably skeptical of what the articles were saying, and they asked my opinion. I am happy to oblige. The worst of the two articles can be found at Big Think. It is entitled “Yale scientists restore brain function to 32 clinically dead pigs.” It then goes on to say:

The image of an undead brain coming back to live again is the stuff of science fiction…But like any good science fiction, it’s only a matter of time before some manner of it seeps into our reality. This week’s Nature published the findings of researchers who managed to restore function to pigs’ brains that were clinically dead. At least, what we once thought of as dead.

None of this is true. The researchers have accomplished something that overturns the current scientific consensus about the survivability of neurons (the “workhorse” cells of the brain). They also might have developed a technology that will significantly improve drug testing, but they haven’t even come close to restoring brain function!

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Soft Dinosaur Tissue Looks Really Young!

“Soft” tissue from an Allosaurus fossil, which is supposed to be 150 million years old. (Image from study being discussed)

In 2005, Dr. Mary Schweitzer stunned the paleontology community by finding soft tissue in a Tyrannosaurus rex fossil that is supposed to be more than 65 million years old. Because it is very difficult to understand how tissue could remain soft for more than 65 million years, many scientists tried to contest her findings. Over the years, however, more discoveries of soft tissue in fossils that are supposed to be multiple millions of years old have been made (see here, here, here, here, and here, for example). As a result, most scientists have come to accept the fact that there is soft tissue in fossils that are up to 550 million years old.

Now the focus on soft tissue in fossils is changing. Scientists are trying to find some chemical mechanism that would allow soft tissue to avoid decay and fossilization over such a long period of time. Dr. Schweitzer herself did experiments to suggest that iron might help to stave off decomposition and fossilization, but from a chemical standpoint, it simply doesn’t work (see here and here).

A reader recently asked me about another proposed explanation that I had somehow missed. The study was published late last year, and while it attempts to explain how soft tissue can avoid decomposition over millions of years, it doesn’t achieve its goal. Instead, it actually gives more evidence that the fossils in the study are very young. However, it does produce some interesting results that require further investigation.

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No, These Researchers Did Not See a Single-Celled Organism Evolve Into A Multicellular Organism!

A green algae in a predator-free environment (far left) and other environments with predators. (click for credit)

A student sent me an article from Science Alert, asking me about its rather bold claim:

Scientists Have Witnessed a Single-Celled Algae Evolve Into a Multicellular Organism…Most of us know that at some point in our evolutionary history around 600 million years ago, single-celled organisms evolved into more complex multicellular life. But knowing that happened and actually seeing it happen in real-time in front of you is an entirely different matter altogether. And that’s exactly what researchers from the George Institute of Technology and University of Montana have witnessed – and captured in the breathtaking, time-lapse footage below.

Over the course of my scientific career, I have learned that many science journalists are terrible at science and not much better at journalism, so I did what I always do when I read about science in the popular press: I found the scientific article upon which it was based. Not surprisingly, the study didn’t do what the article claims. It did find one interesting result, however.

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The “Axis of Evil” in Astrophysics

The European Space Agency’s image illustrating two things that seem to falsify the cosmological principle. (click for credit)

A couple of days ago, I had a fun conversation with a student regarding astrophysics. He seemed very well-informed on the subject, so I begin using some physics “slang” to help move the conversation along. The student picked up on most of the references, but then we began discussing the cosmological principle, which is an assumption upon which the Big Bang model (and many other models of the universe) depends. It essentially states:

Viewed on a large enough scale, the properties of the universe are the same no matter where you are

The student was aware that most observations have never supported the cosmological principle, but he brought up the Cosmic Microwave Background (CMB), which he seemed to think supports it. I countered by mentioning the “Axis of Evil,” and he seemed to think I was joking. I was surprised that he didn’t get the reference, so I explained it to him. He was shocked that he hadn’t heard of it before, so he suggested that I write a blog post about it.

To understand the “Axis of Evil,” you first have to understand the CMB. When astrophysicists were working on the Big Bang model of the universe, which essentially says that the universe “exploded” into being from nothing, they realized that such an “explosion” would leave behind a signature: microwaves that appear from everywhere in the universe. The predicted details of these microwaves varied from paper to paper, but regardless of the details, everyone agreed that if the Big Bang happened, there should be a “background” of microwaves found everywhere in the universe. That’s what became known as the CMB.

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Directed Evolution Wins Nobel Prize

From left to right: Dr. Frances Arnold, Sir Gregory Winter, Dr. George Smith
(Credits:Beavercheme2, Aga Machaj, Univ. Missouri-Columbia)

Yesterday, the Royal Swedish Academy of Sciences announced that the Nobel Prize in chemistry will be shared among three scientists who all used directed evolution to engineer proteins that solve problems. A reader who saw a news story about the announcement asked me to explain what “directed evolution” means, and I am happy to oblige. In directed evolution, scientists use the concepts of variation and selection to take a molecule that already exists in nature and adapt it to do something that they want it to do. Using a concrete example that comes from the research of Dr. Frances Arnold (one of the recipients) is probably the best way to explain the process.

Dr. Arnold’s lab started with a naturally-occurring enzyme charmingly named P450 BM3. Enzymes speed up specific chemical reactions, and P450 BM3 speeds up the reaction in which an oxygen atom is inserted between a carbon atom and a hydrogen atom in a fatty acid molecule. This is an important step in the process by which a living organism breaks down fatty acid molecules. Dr. Arnold’s lab was interested in doing the same kind of reaction, but on a different type of organic molecule: a small alkane. The enzyme P450 BM3 couldn’t initially do that. However, it could weakly speed up that reaction on large alkanes.

Since the enzyme could at least do that, Dr. Arnold thought that she could “tweak” it until it did exactly what she wanted it to do. However, enzymes are absurdly complicated molecules, and human science isn’t very good at making or understanding them. So she decided to let better organic chemists (bacteria) do the heavy lifting. Her lab took the gene that tells bacteria how to make P450 BM3 and subjected it to mutations. They then saw whether or not the resulting enzyme made by bacteria was any closer to being able to do what they wanted it to do. Maybe it did a better job speeding up the reaction on a large alkane, or maybe it was able to speed up the reaction on a shorter alkane. If that was the case, they saved that gene and allowed it to mutate more, seeing if any more progress could be made. If not, they threw it away and tried again.

This is why the process is called “directed evolution.” Dr. Arnold’s lab induced mutations (which are a source of genetic change in organisms) and then selected any enzyme that ended up being better at what they wanted it to do. With enough of those steps, they were able to get what they wanted: an enzyme that inserted an oxygen atom between a carbon atom and a hydrogen atom in a small alkane. In the end, the process had changed just over 2% of the molecule, but that was enough to change it from an enzyme that acted on fatty acids to one that acted on small alkanes.

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No, We Won’t Have Dinosaurs in Two Years!

Even with a LOT of tinkering during embryonic development, only minor changes could be made in a chick’s skull.
(image from Bhullar et. al. article linked below)

A little while ago, I wrote an article about how silly “science journalism” can get. The article was about the popular media’s claim that scientists were about to bring mammoths back from extinction. I explained how the idea was based on real research, but the goal of the research was not to bring mammoths back from extinction. In addition, if anything concrete comes from the work, it will probably be decades from now. In response to that, a student sent me an even sillier article, which comes from that bastion of journalistic integrity, People. It states the following:

Famed paleontologist Dr. Jack Horner, who’s been a consultant on all four films and is the real-life inspiration for Jurassic Park’s dinosaur expert Dr. Alan Grant, believes we’re (optimistically) just five years away from genetically engineering a dinosaur.

This article was written back in 2015, so based on Dr. Horner’s optimistic projection, we should be just two years away from having dinosaurs roaming around in some laboratory.

So what is the source of Dr. Horner’s optimism? He thinks that birds evolved from dinosaurs, so he thinks that we could genetically “turn back the clock” and transform a bird into a dinosaur. He claims that this has already been done to some extent:

In what Horner calls a definitive “proof of concept,” a group at Harvard and Yale “just recently, within the last few weeks, were able to transform the head of a bird back to actually reverse-engineer the bird’s snout back into a dinosaur-like snout.”

There are so many things wrong with that statement, it is hard to know where to start. However, I will give it a try.

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Will Scientists Resurrect the Woolly Mammoth?

Model of a woolly mammoth at the Royal BC Museum in Canada. (click for credit)

One of my former students sent me an article from The Telegraph, a news outlet in the UK. The headline reads:

Woolly mammoth will be back from extinction within two years, say Harvard scientists

The article was written in February of 2017, so the student wanted to know if there would really be living woolly mammoths next year. The answer, of course, is absolutely not. This article is just another example of how many “science journalists” understand neither science nor journalism. Nevertheless, the actual scientific story is interesting, even though it isn’t nearly as sensational as what is indicated in The Telegraph‘s article, or articles found on other sites, such as here and here.

These articles are attempting to report on the Woolly Mammoth Revival Project, which is headed by Harvard professor Dr. George Church. As its website indicates, the goal is not to bring back the identical mammoth species again. Instead, its goal is to create some kind of elephant/mammoth hybrid that can live in colder climates. Why would it want to do that? For ecological engineering.

At some time in the past, woolly mammoth herds (and herds of other cold-adapted animals) roamed what are now the evergreen forests in the northern latitudes. This kept the growth of evergreens in check, making those areas more like grasslands. In addition, the mammoth herds would pack down and scrape away snow. Without this “land reshaping,” snow insulates the soil below, reducing the depth to which it freezes. As the deeper soil thaws, it releases greenhouse gases, and the worry is that those released greenhouse gases will accelerate global warming, aka “climate change.” Now please note that actual data indicate thawing soil will reduce greenhouse gases in the atmosphere, but most “climate change” alarmists aren’t interested in the data.

In the end, then, the Woolly Mammoth Revival Project hopes to populate the north with cold-adapted, elephant-like animals that will once again turn the northern evergreen forests into grasslands, packing down and scraping away the snow as they roam.

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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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Please Stop Believing Facebook, Especially When It Comes to Science!

A picture from a high school experiment that has been hyped on Facebook.

As I was scrolling through Facebook, finding my historical twin and learning what my friends are eating, I noticed a post on my wall. It was from someone I know only through Facebook, but I read her work from time to time, because she is a really good writer. Her post contained the picture above and linked to an article entitled, “WiFi Experiment Done By A Group Of 9th Grade Students Got Serious International Attention. THIS Is Why…” She asked if I knew whether or not the results were legitimate.

The experiment went like this: Students took 12 trays of cress seeds and put 6 of them in one room and 6 in another room. The six trays in one room were next to two WiFi routers, while the 6 trays in the other room were nowhere near a router. They tried to keep everything else (temperature, amount of water given, etc.) the same for all 12 trays. The article says:

After 12 days what the result spoke was clear: cress seeds next to the router did not grow, and some of them were even mutated or dead.

Obviously, then, WiFi routers produce something that kills (and apparently mutates) cress seeds.

I told my Facebook friend that the post reminded me of something that was popular a few years ago. It was an experiment where a person watered a plant with regular water and watered another plant with water that had been in a microwave oven. After several days, the one watered with microwaved water died, while the other one flourished. Obviously, then, microwave ovens are bad for you. Of course, the heart of science is being able to replicate experiments, and many people found that they couldn’t replicate the reported results. Indeed, the Mythbusters did an episode showing that microwaved water didn’t harm plants in any noticeable way.

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