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February 2013 Archives

Mad Scientists of the Modern Age: Lynn Margulis

During the first week of October 2012, we ran a series of blog posts called "Mad Scientists of the Modern Age," in which we featured Jack Parsons, Vladimir Demikhov, Nikola Tesla, Josef Mengele and Barry Marshall. But we were just scratching the surface. In reality, there were plenty of kooky scientists to choose from, and that's probably because there really does appear to be a connection between genius and craziness. Hence, there's no fear that we will ever run out of new subjects to write about.

In that spirit, we would like to welcome our latest inductee into the RealClearScience "Mad Scientist Hall of Fame":
Lynn Margulis is the first female inductee. (Don't say we aren't equal opportunity mockers.) She developed the widely accepted endosymbiotic theory which explains the origin of eukaryotes. Eukaryotic cells contain mitochondria and (if they are photosynthetic) chloroplasts, organelles specialized for the tasks of energy production and photosynthesis, respectively. Intriguingly, they both resemble bacteria structurally, biochemically and genetically. If she had stopped there, Margulis would be remembered as making a powerful contribution to the theory of evolution. But, she had so much more to say.

With James Lovelock, she co-developed the Gaia Theory, which is less theory and more New Age/hippie philosophy. According to its website:

The theory asserts that living organisms and their inorganic surroundings have evolved together as a single living system that greatly affects the chemistry and conditions of Earth's surface. Some scientists believe that this "Gaian system" self-regulates global temperature, atmospheric content, ocean salinity, and other factors in an "automatic" manner. Earth's living system appears to keep conditions on our planet just right for life to persist!
There simply isn't any compelling reason to believe that's true. If it really was true, then scientists shouldn't worry about climate change, ocean acidification, pollution or staying within the confines of the planetary boundaries because Earth can take care of itself.

Hippie philosophy is generally harmless, so we can forgive that. But two of her other beliefs weren't as harmless.

Margulis was a 9/11 truther. On a website called "Scientists for 9/11 Truth," a statement attributed to her reads:

Certainly, 19 young Arab men and a man in a cave 7,000 miles away, no matter the level of their anger, could not have masterminded and carried out 9/11: the most effective television commercial in the history of Western civilization. I suggest that those of us aware and concerned demand that the glaringly erroneous official account of 9/11 be dismissed as a fraud and a new, thorough, and impartial investigation be undertaken.
Even worse than that is the fact that Margulis was also an AIDS denier. Instead of HIV, she believed that the symptoms associated with AIDS were caused by a symbiotic relationship with the bacterium that causes syphilis. (Apparently, after the success of her endosymbiotic theory, she believed that everything was caused by symbiotic relationships.) Incredibly, she claimed the bacterium "becomes part of the patient's genome" and is "undetectable."

That is unbelievable kookiness, especially for a biologist. While some viruses can integrate into the human genome, bacteria do not. And as for being "undetectable," the existence of STD tests would contradict that.

Margulis passed away from a stroke in November 2011. Her legacy is certainly mixed: She helped rewrite the textbooks on evolution, but her embrace of harmful pseudoscience has landed her in the hall of scientific infamy.

(Photo: Lynn Margulis via Wikimedia Commons)

February 2013 Archives

RealClearScience at the Movies: 'Die Hard 5'

For the first time ever, I was invited to a movie pre-screening. One of my friends who invited me also has been relentlessly lobbying for a series called, "RealClearScience at the Movies," where (as you have probably guessed), we analyze the good and bad science coming out of Hollywood. Thus, in honor of his request, I present the inaugural post in what might become an off-and-on again series: "RealClearScience at the Movies: A Good Day to Die Hard."
(NOTE: One plot point will be revealed in this post, but no major spoilers. But, given that this is a mindless action movie, there isn't much to spoil. You probably already know how it's going to end.)

I've actually never seen any of the Die Hard films, so I came in with extremely low expectations. I wasn't disappointed. There was plenty of senseless violence and mayhem, and probably a fair share of physics-defying stunts. But, I'm not a physicist, so I will focus on the two things that I did recognize as scientifically incorrect. 

The first was after a long fight when Jack McClane (the son of John McClane, who is Bruce Willis' character) was injured. A piece of metal had pierced his side, and his father mocked him by asking (paraphrased), "When did you get your last tetanus shot?"

This is a common misconception. Tetanus is not caused by rusty nails; instead, it is caused by a soil-dwelling bacterium, Clostridium tetani. This anaerobic bacterium also forms spores, and these spores are readily found in the soil. What else can be found in the soil? Rusty nails. If you step on a rusty nail that is contaminated with soil, there is a very good chance that you just inoculated your foot with Clostridium spores. As an anaerobe, Clostridium can't grow in healthy tissue (due to oxygen), but injured tissue provides a suitable environment. As it grows, it releases a potent toxin that causes tetanus, which manifests as uncontrollable muscle spasms and contractions and even asphyxiation.

So, technically, the movie wasn't "wrong" to mention tetanus in conjunction with a wound (since Clostridium can enter the body through any wound), but John McClane perpetuated a widespread misconception by not providing a more detailed explanation of the underlying microbiology to his injured son. We'll call it an error of omission.

The second error that caught my attention was far worse. Our heroic team heads to Chernobyl, and one of the characters whips out a device that reminded me of the proton pack from the movie Ghostbusters. The character used it to "neutralize" the radiation.

Ummm, no.

Radioactivity cannot be neutralized. That's one of the reasons why radioactive waste is such a menace. Not only is it toxic, but some radioactive isotopes last a really long time, and there isn't anything we can do about it except wait until they decay. Depending on the isotope, that could take anywhere from fractions of a second to billions of years. The long half-lives of some radioactive isotopes is why we build long-term storage facilities, such as Yucca Mountain (which the Obama administration shut down for political reasons in 2009).

Overall, the film was enjoyable in that it fulfilled my testosterone-fueled need to see explosions and car crashes. But, two of my friends -- both of whom were fans of the Die Hard series -- hated it.

(Image: Movie poster for 'A Good Day to Die Hard' via Wikimedia Commons)
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February 2013 Archives

We Are Animals Living in a Microbial World

"Living in a material world,
And I am a material girl."

--"Material Girl" by Madonna

That song would have been much better if the word "material" was replaced by "microbial." Let me explain.

Animal evolution traditionally has been viewed as the result of interactions between animals or with the physical environment. For instance, bunny rabbits became fairly good at sprinting quickly because the slower ones got eaten by wolves. Likewise, because of environmental temperature fluctuations, mammals evolved hair to help keep their bodies warm. (Interestingly, elephants seem to use their sparse hairs to help cool off!)

However, this understanding of evolution overlooks a huge missing piece of the puzzle: bacteria. To put it bluntly, complex lifeforms probably would never have evolved on planet Earth if it weren't for bacteria. Besides oxygenating the early Earth, bacteria also play crucial roles in nutrient cycling. On a personal level, inside your body, friendly bacteria help metabolize food, block dangerous pathogens and even help develop the immune response. In fact, there are about 100 trillion of them and only 10 trillion cells of "you," meaning that your own body cells are outnumbered 10-to-1!

Because bacteria have always interacted with animals, it is very likely that bacteria helped shape animal evolution. And that is exactly the case being made by a new "Perspectives" article in PNAS titled, "Animals in a Bacterial World, a New Imperative for the Life Sciences."

The authors list several dozen examples to bolster their case, but a few in particular are worth mentioning.

About 3.8 billion years ago, a primordial cell formed, known as the last universal ancestor (LUA). From this organism, three domains of life evolved: Bacteria, Archaea (weird and bacteria-like) and Eukaryota (nucleated cells and multicellular organisms).
Since all life is related, most organisms have about 1/3 of their genes in common. Of the roughly 23,000 genes in the human genome, for instance, 37% are similar to genes in Bacteria and Archaea. Another 28% are similar to genes in unicellular eukaryotes. (Think: yeast and algae.) Thus, a full 65% of human genes show similarity to microbes. Only 6% are found uniquely in primates.

Not only do animals share evolutionary history with microbes, but they also continue to interact with them on a daily basis -- often in very profound ways. Bacteria living inside of animals can provide them with metabolic capabilities that the animal itself does not possess. Cows couldn't eat grass if it weren't for the resident microbes that ferment it in the cow's rumen. Surely, the evolution of the cow was heavily influenced by -- if not largely dependent on -- its microbial allies.

But cows aren't the only ones with helpful bacteria in their digestive system. As mentioned above, humans also come with a full complement of gut flora. In addition to aiding our digestive system, gut microorganisms also influence distant parts of the body -- including the brain. It is now thought that gut bacteria interact with the vagus nerve, allowing them to alter brain physiology.

The authors conclude that disturbing bacterial communities -- whether within our own bodies or in the environment -- could potentially have devastating impacts on all the rest of life. Considering that this is indeed a microbial world, they might very well be right.

Source: Margaret McFall-Ngai et al. "Animals in a bacterial world, a new imperative for the life sciences." PNAS. Published online before print: February 7, 2013. doi: 10.1073/pnas.1218525110

(Image: Phylogenetic Tree of Life via Wikimedia Commons)
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