Category: Modern Science

Stem Cells: Induced Ones Make The Same Proteins as Embryonic Ones

This illustration shows the first few steps of embryonic development. Embryonic stem cells, which are pluripotent, are colored blue. (Click for credit.)

When your mother’s egg cell was fertilized by your father’s sperm cell, the result was a single cell, called a zygote. That cell had all the information necessary to develop into the person you are today. In other words, it could produce everything necessary to build you. So that single cell had the capability of developing into any human cell. We call such cells totipotent cells. Of course, in order to make all those cells, the zygote had to start reproducing, resulting in an embryo.

As this cell (and its progeny) reproduced, the number of cells in the embryo grew. When that reproduction had produced about 12 cells, you were in the morula stage of your development, and on a microscopic level, you resembled a mulberry. As your cells continued to reproduce, they formed a hollow sphere called a blastocyst. At one end of the hollow sphere, there was a bunch of cells called the inner cell mass, which is represented by the blue cells in the illustration above. That inner cell mass developed into all the organs and tissues that make up your body.1

Interestingly enough, however, the cells in that inner cell mass were no longer totipotent. They could not, for example, form the kind of cells that make up the outer layer of the blastocyst, which are shown in yellow in the illustration above. However, they could end up becoming any of the cells in any of the organs or tissues of your body. As a result, they are called pluripotent cells. As they continued to reproduce, they started “choosing” what kind of cell they would become. Some of those pluripotent cells, for example, became skin cells. Once they did that, we say that the cells had differentiated. This means they lost their pluripotency, and would no longer be able to become some other type of cell. As a result, they would end up doing the same job for the rest of their lives.

Pluripotent cells are often called stem cells, and they have a lot of potential in medicine. After all, if someone suffers from severe organ damage, I could theoretically get his or her body to rebuild that damaged organ if I supplied it with enough stem cells. The stem cells could then differentiate into whatever cells are needed to replace those that died when the organ was damaged. While this sounds wonderful, there is a problem. The most ready source of pluripotent cells come from the blastocyst stage of an embryo’s development. If I remove those pluripotent cells from the blastocyst, I have embryonic stem cells, but unfortunately, the embryo dies.

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Antibiotic Resistance is Not a Modern Phenomenon

Antibiotic resistance in bacteria is often cited as evidence for evolution. For example, in his book, The Greatest Show on Earth: The Evidence for Evolution, Richard Dawkins says:1

Many bacterial strains have evolved resistance to antibiotics in spectacularly short periods. After all, the first antibiotic, penicillin, was developed, heroically, by Florey and Chain as recently as the Second World War. New antibiotics have been coming out at frequent intervals since then, and bacteria have evolved resistance to just about every one of them.

However, we’ve known for quite some time that at least some antibiotic resistance did not evolve after the production of antibiotics. Instead, it existed before antibiotics were developed. For example, in 1988, bacteria were recovered from the frozen bodies of Arctic Explorers who died in 1845, long before antibiotics had been produced. When the bacteria were revived, some were found to be already resistant to certain antibiotics.2 So contrary to Dawkins’s claim, it is not at all clear that bacteria have evolved resistance to just about every antibiotic. Some possessed resistance before antibiotics were ever made

A recent study published in the journal Nature confirms this fact at a very basic level.

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Good News in Autism Research

A model of the human brain, highlighting the different lobes. Click for credit.

Autism is a poorly-understood neurological disorder that affects many people throughout the world. Unfortunately, because it is poorly-understood, there is an tendency for people to blame autism on anything they don’t like. For example, there are those who try to claim that vaccines cause autism. When confronted with the overwhelming scientific evidence against such a claim, many of those people simply ignore the data.

For example, not long ago, I did an online debate on whether or not vaccines cause autism. The debate was heavily-publicized by the anti-vaccination group that hosted it, but after the debate, all mention of it was removed from the group’s website. Why? Because I simply presented the data that clearly show there is no way autism could be related to vaccination. The group decided to pull all mention of the debate rather than risk some of their readers learning what the data actually say about vaccines and autism!

Fortunately, most people are more interested in finding the real causes of autism. Thus, they have looked at the data and realize that vaccines simply aren’t a possibility. As a result, they have moved on and are looking at other possible causes. About a year ago, I blogged about a study that tried to pin down the genetic causes of autism. Since autism is a highly heritable disease1, it makes sense that the cause should be genetic. However, rather than implicating just a few genes, the study came to the conclusion that there are a lot of genes involved in autism. That made the results rather disheartening, because it is hard enough to treat a disease that is caused by only one or two genes. How can you possibly treat a disease that is caused by lots and lots of genes?

Well, researchers from UCLA might have found an answer to that question.

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Our Galaxy Is “Just About Perfect”

A model of what astronomers think the Milky Way galaxy looks like.
(NASA image)
The more we look at our place in the universe, the more we find how special it really is. For example, we are in a solar system that is a part of the spiral galaxy known as the Milky Way. Our place in the Milky Way is quite special, because we are essentially at the corotation distance from the center of the galaxy.1 This means we rotate around the center of the galaxy at the same rate as the spiral arms of stars that make up the galaxy. This produces a very stable environment for our planet, which is necessary in order for it to support life.

There are many, many other things we have learned about our solar system and the earth in particular that make it clear we are on a very special planet that orbits a very special star. If you are interested in learning more about how special our place in the universe is, I strongly recommend the book The Privileged Planet: How Our Place in the Cosmos is Designed for Discovery by Guillermo Gonzalez and Jay Wesley Richards. It details many discoveries in earth and space science that clearly show how special the earth and its solar system are. If even one of the many, many special factors that make life possible in our little corner of the universe were not present, you wouldn’t be around to be reading this blog post.

Even though we have known for a long time that the earth, the star we orbit, and our placement in the Milky Way galaxy are all quite special, we are just now beginning to find out that even the galaxy itself is special.

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God’s Cleanup Crew Is Tougher Than Expected!

NASA satellite photo of oil on the surface of the Gulf of Mexico roughly 20 days before the Deepwater Horizon well was capped.
On two previous occasions (here and here) I commented on the Deepwater Horizon disaster. In both cases, I noted how God’s natural cleanup crew (made up of bacteria) was busy getting rid of the oil that had been so carelessly dumped into the Gulf of Mexico. The speed and efficiency with which the bacteria were getting rid of the pollution have been breathtaking. Indeed, in the second post linked above, I discussed how scientists thought that methane from the disaster would persist for up to a decade in the Gulf, when in fact, it wasn’t even able to stick around for a year!

While these (and many other) studies showed that bacteria were cleaning up the oil better than anyone expected, there was one nagging worry: what about the oil that was floating on the surface of the Gulf? Most of the studies dealing with bacterial decomposition in the Gulf concentrated on the oil that was deep underwater. The surface of the Gulf of Mexico is a much different environment from the deep waters, and it was feared that bacteria would not be as good at decomposing the oil that was floating on the surface.

Indeed, a 1995 study specifically looked at bacterial activity on the surface of the Gulf of Mexico near where the Deepwater Horizon disaster occurred. The researchers noted that the mix of chemicals in that region is not ideal for good bacterial activity. They even did experiments where they added excess glucose to the water and watched how the bacteria responded. While bacteria typically love to eat glucose, the researchers saw very little increase in bacterial activity. This led them to conclude that the surface waters were not very suitable for bacterial-led cleanup.1

The scientists at the Woods Hole Oceanographic Institution are, of course, familiar with the results of this study. So they thought that the oil on the surface of the Gulf would not be cleaned up nearly as quickly as the oil that was deep in the Gulf. Fortunately, they were wrong.

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Science Can’t Prove Anything

Sir Karl Popper's foundational work, The Logic of Scientific Discovery, makes it clear that science cannot prove anything (click for credit)
In one of my science textbooks, I make the statement that science cannot prove anything.1 I am always surprised at how controversial such a matter-of-fact statement is to some people. Almost every year, at least one student or parent will contact me simply aghast that I would write something like that in a science textbook. After all, science has proven all sorts of things, hasn’t it?

Of course it hasn’t. In fact, it is impossible for science to prove anything, because science is based on experiments and observations, both of which can be flawed. Often, those flaws don’t become apparent to the scientific community for quite some time. Flawed experiments and observations, of course, lead to flawed conclusions, so even the most secure scientific statements have never been proven. There might be gobs and gobs of evidence for them, but they have not been proven.

Karl Popper probably wrote the most important book related to this concept, which was titled The Logic of Scientific Discovery. Interestingly enough, he originally wrote it in German and then rewrote it in English. As a result, it is one of the few books that is published in two different languages but was never translated. The author wrote both versions. In this book, he argues that science should follow a methodology based on falsification. He shows quite clearly that while science cannot prove anything, it can falsify ideas that are currently thought to be true. He therefore argues that the test of any real scientific theory is whether or not it can be falsified. If not, then it is not truly a scientific theory.

There are a lot of scientists who disagree with Popper that falsification is the key to whether or not a theory is scientific. However, few would argue with his point that science cannot prove anything. Indeed, the journal Science seemed to forget this fact for a moment, but an astute reader chastised the editor, who admitted he was wrong.

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I Was Wrong

Part of being a scientist is following the data no matter where they lead. Sometimes, that ends up requiring you to admit you have been wrong about something. No matter how painful that admission may be, it is a necessary part of being a good scientist. If the data speak, the scientist must listen. I regret to inform my readers that the data have spoken, and something I have believed in for some time has been demonstrated to be quite wrong. While it might be painful for you to read, believe me, it is more painful for me to write:

Cats are not more elegant than dogs, at least not when it comes to the way they drink!

In case you don’t remember the piece I wrote on this, here is what I said:

I have always been a cat lover. It’s not that I don’t like dogs; I do. In fact, I have one friend who says his dog misses me for a while every time I leave his home. Nevertheless, when it comes to what pets I want to have in my home, cats win over dogs every time. I have always found cats more… well… elegant than dogs. Now, a new study confirms this is true, at least when it comes to how they drink.

In the post, I discussed a study that showed the physical mechanism by which cats drink and compared it to the mechanism by which dogs drink. My conclusion was clear: cats are simply more elegant than dogs in many ways, including the way they drink.

Well, it turns out that I was wrong.

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We Have Liftoff!

NASA’s project “Juno” lifted off today at approximately 12:30 PM. It’s destination: the planet Jupiter. I encourage you to watch the two-minute video of the launch below. It still fills me with wonder that we can launch a rocket into space and then plan its flight so it reaches a planet that is hundreds of millions of miles away from earth! This video is especially interesting, because the rocket had a camera facing down, so you not only get to see the surface of the earth as the rocket races away from it, but you also get to see the solid rocket boosters fall off as they run out of fuel.

Even though the rocket launched today, Juno will not reach Jupiter until July of 2016. Why does it take so long to get there? Well, Jupiter can be somewhere between 390,682,810 miles and 576,682,810 miles away from earth, depending on when you check. However, it wouldn’t necessarily take almost five years for the spacecraft to travel that far. It takes that long because Juno will travel a lot farther than that.

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Does This Really Blow a Gaping Hole in Global Warming?

A longtime reader of this blog sent me a blog post from Forbes entitled, “New NASA Data Blow Gaping Hole In Global Warming Alarmism.” With such a provocative title, of course, I had to read it.

The blog post makes some amazing claims. It says that the data, published in the Journal Remote Sensing, demonstrate that global climate models do not agree with what happens in the real world when it comes to how much heat the earth is radiating into space. It then says:

The new findings are extremely important and should dramatically alter the global warming debate.

Now this bothered me a bit, because we’ve known for a while that the global climate models don’t work very well. Back in 2009, for example, Richard Lindzen showed that global climate models don’t conform to the data when it comes to how the earth reacts to rising sea surface temperatures. Why should a paper that reaches essentially the same conclusion suddenly change the global warming debate?

The blog post concludes with this statement:

When objective NASA satellite data, reported in a peer-reviewed scientific journal, show a “huge discrepancy” between alarmist climate models and real-world facts, climate scientists, the media and our elected officials would be wise to take notice. Whether or not they do so will tell us a great deal about how honest the purveyors of global warming alarmism truly are.

The way the author of the blog post, James Taylor, wrote about these data made me want to read the scientific paper that contained them. When I read it, however, I found that the “data” were significantly less dramatic than what Mr. Taylor indicates.

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Is Anti-Boring Equal to Exciting? We Might One Day Know!

This public-domain drawing depicts a hydrogen atom (foreground) and an anti-hydrogen atom (background).

Although the term “antimatter” might sound like something from Star Trek, it is actually quite real. When I do nuclear chemistry experiments, for example, one of the ways I calibrate certain detectors is to use a radioactive sodium-22 source. One of the ways this isotope decays is by emitting the antimatter version of the electron (called a positron). That positron rather quickly finds an electron, and they annihilate each other, which results in two high-energy photons where there was once matter and antimatter. The energy of those two photons is well known, so they can be used to calibrate detectors.

Of course, this points to a big problem when it comes to studying antimatter – it doesn’t stick around very long. Since there is all sorts of matter around, any antimatter that gets produced rather quickly finds some matter, and annihilation is usually what results. Nevertheless, some scientists try to do all that they can with antimatter for whatever brief time is available to them.

One of the cool things you can do with antimatter is make anti-atoms. For example, consider boring old hydrogen. It consists of a single proton that is orbited by a single electron. How could you possibly spice that up? What about making anti-hydrogen? Take a positron (remember, that’s the antimatter version of an electron) and force it to orbit the antimatter version of the proton (which is called an antiproton). You now have the antimatter version of a hydrogen atom! Believe it or not, that has actually been done before. In the lab, scientists have made anti-hydrogen atoms. The problem is that none have been able to preserve the anti-hydrogen they have made for more than a fraction of a second.

Now a group of scientists at the European particle physics lab called CERN has managed to make anti-hydrogen and preserve it for the impossibly long time of fifteen minutes!1

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