A consummation devoutly to be wished

When I was in college, I had an eight a.m. calculus class with a woman who used to drag herself in, large coffee in her hand, looking like death warmed over.  The first time this happened, I thought she'd just pulled an all-nighter either studying or partying -- both common occurrences in college -- but then I noticed it was day after day.  The poor woman never looked wide awake, and always seemed just this side of miserable.

Finally, being the subtle and compassionate person you all know me to be, I said to her, "What the hell is wrong with you?", or words to that effect.

She explained to me that she had serious sleep issues.  She'd get back to her dorm from her last class in the afternoon, still feeling exhausted, but then she'd get a second wind in the early evening.  Come a reasonable bedtime -- say, ten-thirty or eleven -- she was wide awake.

"I don't even bother going to bed," she told me.  "I tried it, more than once, and lay there for hours staring at the ceiling.  Now I just get up and try to be productive."

Until about four-thirty or five in the morning, when she'd finally feel tired.  Then she'd go to sleep, and her alarm would go off at six, and she'd start the whole cycle again -- with about an hour's worth of sleep.

I didn't find out until much later that what she was suffering from has a name; circadian dysrhythmia.  Basically, it's when your biological clock is completely out of sync with the rest of the world.  It's a little like a permanent case of jet lag.  And sadly, even now, forty years later, it's still remarkably resistant to treatment.

It's been the conventional wisdom for some time that circadian rhythms are mediated through a part of the brain called the hypothalamus.  And this is clearly part of the answer; sleepiness is correlated with increased activity in the anterior part of the region, and an increase in the hypothalamic production of the neurotransmitter gamma amino-butyric acid (GABA), which has an inhibitory effect on neural excitation.

[Image is licensed under the Creative Commons Jamain, Sleeping man J1, CC BY-SA 3.0]

But two new papers, published simultaneously last week in the journal Cell, have shown us that things may not be that simple.  (Are they ever?)  Both studies were done at the University of California - Irvine, and have shown that the network of internal clocks that regulates our metabolism, activity, alertness, and other cyclic behaviors are not limited to the brain -- that other parts of the body also have significant contributions to modulating our daily cycles.

In the first, titled, "BMAL1-Driven Tissue Clocks Respond Independently to Light to Maintain Homeostasis," researchers found that a chemically-driven clock exists... in our skin cells.  The authors write:

Circadian rhythms control organismal physiology throughout the day.  At the cellular level, clock regulation is established by a self-sustained Bmal1-dependent transcriptional oscillator network [a cyclic rise and fall of gene activity associated with light levels].  However, it is still unclear how different tissues achieve a synchronized rhythmic physiology.  That is, do they respond independently to environmental signals, or require interactions with each other to do so?  We show that unexpectedly, light synchronizes the Bmal1-dependent circadian machinery in single tissues in the absence of Bmal1 in all other tissues.  Strikingly, light-driven tissue autonomous clocks occur without rhythmic feeding behavior and are lost in constant darkness.

Maybe not so shocking, given that our skin is at least partly exposed to the light.  What is more surprising is the second paper, which found that a light-dependent circadian rhythm takes place in our livers:

Mammals rely on a network of circadian clocks to control daily systemic metabolism and physiology.  The central pacemaker in the suprachiasmatic nucleus (SCN) is considered hierarchically dominant over peripheral clocks, whose degree of independence, or tissue-level autonomy, has never been ascertained in vivo.  Using arrhythmic Bmal1-null mice, we generated animals with reconstituted circadian expression of BMAL1 exclusively in the liver (Liver-RE)...  [R]hythmic clock gene expression is lost in Liver-RE mice under constant darkness.  Hence, full circadian function in the liver depends on signals emanating from other clocks, and light contributes to tissue-autonomous clock function.

"The results were quite surprising," said Paolo Sassone-Corsi, who co-authored both studies.  "No one realized that the liver or skin could be so directly affected by light...  The future implications of our findings are vast.  With these mice, we can now begin deciphering the metabolic pathways that control our circadian rhythms, aging processes and general well-being."

It's undeniable that sleep plays a central role in both mental and physical health, and that the vast majority of us don't get sufficient sleep either in quantity or quality.  The more scientists find out about how our sleep cycles and other circadian rhythms are modulated, the greater the likelihood there'll be a treatment for people like my long-ago college acquaintance -- and even for simple insomniacs like myself.

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As will be obvious to any long-time readers of Skeptophilia, I have a positive fascination with things that are big and scary and can kill you.

It's why I tell my students, in complete seriousness, if I hadn't become a teacher I'd have been a tornado chaser.  There's something awe-inspiring about the sheer magnitude of destruction they're capable of.  Likewise earthquakes, hurricanes, wildfires...

But as sheer destructive power goes, there's nothing like the ones that are produced off-Earth.  These are the subject of Phil Plait's brilliant, funny, and highly entertaining Death From the Skies.  Plait is best known for his wonderful blog Bad Astronomy, which simultaneously skewers pseudoscience and teaches us about all sorts of fascinating stellar phenomena.  Here, he gives us the scoop on all the dangerous ones -- supernovas, asteroid collisions, gamma-ray bursters, Wolf-Rayet stars, black holes, you name it.  So if you have a morbid fascination with all the ways the universe is trying to kill you, presented in such a way that you'll be laughing as much as shivering, check out Plait's book.

[Note:  If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Skin deep

We were talking in my AP Biology class yesterday about the potential for skin damage from exposure to ultraviolet light.  Later in the day,  a student sent me a YouTube video called "How the Sun Sees You" that uses a UV-sensitive camera to see the sun damage on people's skin (and also illustrates that sunscreen does work, given that it looks an opaque black when filmed in the ultraviolet region of the spectrum).

All of which is well and good, but then I scrolled down to the comments section, which I know I should never do, and I found the following.  Spelling and grammar are as written, so I don't use up my "sic" allotment all in one go:

First off everyone has to stop believing that Melanin a.k.a. Carbon protects us from u.v. rays.  Carbon in the skin actually absorbs ultraviolet rays in a process that is now being called Ultrafast Internal Conversion.  Not one person has mentioned this..  The Elemental Compound for C Carbon is 666.  6 Electrons 6 Neutrons 6 Protons.  The origins of the 666.  The Catholics call It "the mark of beast" which is code for "mark of the our destroyers"  We all know that Carbon is the building blocks of life.  Carbon defines life therefore us Moors who are incorrectly referred to as "Black People" are the building blocks for Human life and biology.  This is true because no one else on the planet possesses the levels of Carbon in the body and brain quite like The Moors. (remember a moor is a black man or women)  In other words, us "Black people" are and forever will be The genetic template for the Human being.  Black ppl we are Human In it's truest form.  Of course there are plenty lies circulating the damn truth.  All non black people are merely human hybrids.  All races were genetically engineered from the supreme Human.  Clones much?  DARK POWER!!

So naturally I thought, "Well, that's a viewpoint I've never run into before."  (I also thought, "I hope this person is on medication" and "this is what it looks like when someone fails high school biology.")  But I did some research, and I found out that this is not the claim of a lone wacko.  This is the claim of a large number of wackos.  There's a whole school of thought (although I hesitate to use either word in this context) that revolves around the contention that people of African descent are superior because they have lots more carbon in them.

Take, for example, the page "Carbon & Melanin Secret of Secrets" over at the amazingly wacky site Godlike Productions.  In it, we find a wall of text that can be summarized as follows:

• Carbon is some seriously mystical stuff.  Besides the 6-6-6 thing mentioned above, it has four bonds that are shaped like a swastika.
• It also has something to do with the Buddhist "om," the Christian cross, and the Greek letters alpha and omega.
• Melanin is dark.  So is carbon.  Therefore melanin is carbon.
• Melanin is the "key to life" and is the "organizing molecule for living systems."
• Melanin is an ordinary conductor, a semiconductor, and a superconductor.  Don't ask me how it can be all three at the same time.
• Satan and Saturn are the same thing.
• Because the symbol for carbon is C, and the symbol for cytosine (one of the nitrogenous bases in DNA) is C, they're the same thing.  It couldn't be because in English, both of them have names that start with "c."
• Some other weird stuff about DMT and alchemy and prophecies that frankly I couldn't read because my eyes were spinning.

I read this whole thing with an expression like this:

What bothers me most about all of this is not that crazy people are making shit up.  That's what crazy people do, after all.  What bothers me is that apparently this claim has gotten some traction amongst people who want justification for believing that dark-skinned humans are intrinsically better than light-skinned humans, and who cannot even be bothered to take a look at the Wikipedia page for melanin, wherein we find that melanin isn't carbon.  It contains carbon, but after all, so does chalk, which last I looked was white.

The ironic thing is that when you talk to actual anthropologists and geneticists, most of 'em will tell you that the biological basis for race is tenuous at best.  Race is a cultural phenomenon, not a genetic one.  If you want your mind blown on this topic, consider the following quote from Alan Goodman:

Richard Lewontin did an amazing piece of work which he published in 1972, in a famous article called "The Apportionment of Human Variation." Literally what he tried to do was see how much genetic variation showed up at three different levels. 

One level was the variation that showed up among or between purported races. And the conventional idea is that quite a bit of variation would show up at that level. And then he also explored two other levels at the same time. How much variation occurred within a race, but between or among sub-groups within that purported race. 

So, for instance, in Europe, how much variation would there be between the Germans, the Finns and the Spanish? Or how much variation could we call local variation, occurring within an ethnicity such as the Navaho or Hopi or the Chatua? 

And the amazing result was that, on average, about 85% of the variation occurred within any given group. The vast majority of that variation was found at a local level. In fact, groups like the Finns are not homogeneous - they actually contain, I guess one could literally say, 85% of the genetic diversity of the world. 

Secondly, of that remaining 15%, about half of that, seven and a half percent or so, was found to be still within the continent, but just between local populations; between the Germans and the Finns and the Spanish. So, now we're over 90%, something like 93% of variation actually occurs within any given continental group. And only about 6-7% of that variation occurs between "races," leaving one to say that race actually explains very little of human variation...

But, for the most part, you know that the basic human plan is really the basic human plan, and is found almost anywhere in the world. Most variation is found locally within any group. Why don't we believe that? Because we happen to ascribe great significance to skin color, and a few other physical cues... And, in fact, though, these may happen to be a few of the things that do widely vary from place to place. But, that's not true under the skin. Rather, quite another story is told by looking at genes under the skin.

Which should really inform us about how we treat people who don't look like us, shouldn't it?  We're all human.  We have a vast overlap in our genetics, even if you choose two people who look very different from each other.  And at our cores, most of us want the same things -- food, shelter, love, security, compassion.  When we start claiming that people of different ethnicities deserve different levels of privilege, we're engaging in a mindset that is not only destructive, it's counterfactual.

And that applies to all racists equally, whether they're neo-nazis or cranks who claim that anyone without much melanin in their skin is an evil hybrid clone.