Fish tales

Undoubtedly you are aware of the outrage from people on the anti-woke end of the spectrum about Disney's choice of Black actress Halle Bailey to play Ariel in their upcoming live-action remake of The Little Mermaid.

This is just the latest in a very long line of people getting their panties in a twist over what fictional characters "really" are, all of which conveniently ignores the meaning of the words "fictional" and "really."  Authors, screenwriters, and casters are free to reimagine a fictional character any way they want to -- take, for example, the revision of The Wizard of Oz's Wicked Witch of the West into the tortured heroine in Gregory Maguire's novel (and later Broadway hit) Wicked.  This one didn't cause much of a stir amongst the I Hate Diversity crowd, though, undoubtedly because the character of the Witch stayed green the whole time.

But that's the exception.  In the past, we've had:

• A French professor claiming the Smurfs are communists
• An Islamic cleric issuing a fatwa against Mickey Mouse
• Right-wing media calling Dora the Explorer an illegal immigrant
• The Vatican declaring that the Simpsons are Roman Catholic

The current uproar, of course, is worse; not only is it blatantly racist, it's aimed at a real person, the actress who will play Ariel.  But these lunatics show every day that they care more about fictional characters than they do about actual people; note that the same folks screeching about Black mermaids seem to have zero problem with using public funds to transport actual living, breathing human beings to another state, where they were dropped on a street corner like so much refuse, in order to own the libs.

Oh, but you can't mess about with the skin color of mermaids.  In fact, the outrage over this was so intense that it has triggered some of them to invoke something they never otherwise give a second thought to:

Science.

Yes, if you thought this story couldn't get any more idiotic, think again.  Now we have members of the Mermaid Racial Purity Squad claiming that mermaids can't be Black, because they live underwater, and if you're underwater you can't produce melanin.

I wish I was making this up.  Here's a direct quote:

Mermaids live in ocean.  Underwater = limited sunlight.  Limited sunlight = less melanin.  Less melanin = lighter skin color.  Because they live underwater, which has no access to light beyond a certain depth, Ariel and every other mermaid in existence would be albino.

And another:

Correct me if I'm wrong.  But isn't it physically impossible for Ariel to be black?  She lives underwater, how would the sun get to her for her to produce melanin?!  Nobody thought this through..?

Okay, well, correct me if I'm wrong, but applying science to a movie in which there's a singing, dancing crab, a sea witch with octopus legs, and a character named Flounder who clearly isn't a flounder is kind of a losing proposition from the get-go.

Fig. 1.  Flounder from The Little Mermaid.

Fig. 2.  An actual flounder.

Plus, there are plenty of underwater animals that aren't white, which you'd think would occur to these people when they recall the last science book they read, which was One Fish Two Fish Red Fish Blue Fish by Dr. Seuss.

Oh, and another thing.  It's an ironic fact that the squawking knuckle-draggers who complain about "wokeness" every time some fictional character they like isn't played by a White American and are the same ones who pitch a fit at any kind of representation of diversity, be it in books, movies, music, or whatever, conveniently overlook the fact that (1) Hans Christian Andersen, who wrote The Little Mermaid, was bisexual, and (2) there's a credible argument that the original story itself was inspired by his grief at having his romantic advances rejected by his friend Edvard Collin.  (In fact, in the original story, the mermaid doesn't marry the prince -- he goes off and marries a human girl, just as Collin himself did, and the mermaid weeps herself to death.  Not a fan of happy endings, Andersen.)

Anyhow, anti-woke people, do go on and tell me more about "reality" and "what science says."  Hell, have at it, apply science anywhere you want.  Start with climate change and environmental policy if you like.  Or... does it only matter to you when the subject is people who aren't the right color, gender, ethnic origin, nationality, or sexual orientation?

****************************************

Black as the night

You wouldn't think that fish living three miles deep in the ocean, far beneath the level that sunlight can penetrate, would worry much about being seen.

Well, I'm not sure they're worried, exactly.  But they still have the problem that if they do somehow get seen, they're likely to get eaten.

This lies at the heart of the reason that bioluminescence exists in the deep ocean.  You probably know that bioluminescence is the ability of some organisms to use chemical reactions in their bodies to emit light.  (Fireflies are a common example.)  In the deep ocean, it was thought the main reason animals might do this is to create a lure; the illuminated "fishing pole" of the grotesque angler fish brings in curious smaller fish, which then get turned into lunch.

[Image licensed under the Creative Commons Masaki Miya et al., Bufoceratias, CC BY 2.0]

There are other functions for light-emitting structures besides lures.  Squid that live in shallow water have ink they squirt into the water then they're attacked, creating a dark cloud to confuse the predator, thus allowing the squid to escape.  But if you live at a depth where its perpetually dark, black ink is fairly useless; so there are deep-sea squid that emit luminescent ink, creating a burst of light to startle the predator and give the would-be dinner a chance to live for another day.

Last week in Current Biology, though, there was a paper wherein I learned about another reason for bioluminescence in the deep ocean.  In "Ultra-black Camouflage in Deep-Sea Fishes," by Alexander L. Davis, Sönke Johnsen, and Karen J. Osborn (Duke University), Kate N. Thomas (The London Museum of Natural History), Freya E. Goetz (Smithsonian National Museum of Natural History), and Bruce H. Robison (Monterey Bay Aquarium Research Institute), we read about fish like the evocatively-named fangtooth, Pacific blackdragon, and black swallower, whose skin is amongst the blackest naturally-occurring substances, reflecting less than 0.5% of the light the falls on it.

But as with the squid ink, why bother to evolve such dark skin if there's no light there to reflect?  The answer turns out to be that there is light there to reflect; the bioluminescence emitted by other predatory fish.  If you're in the complete darkness, even the reflection of a tiny amount of light from your body might give away your position.  So this is a third reason for deep-sea bioluminescence; not as a lure, nor a distraction, but as a searchlight.

These fish, however, are so dark that even in bright sunlight they look like black silhouettes, as study co-author Karen Osborn found out when she tried to photograph them.  This confers a significant advantage over other fish, even if there's only a marginal difference in the skin blackness.  The authors write:

At low light levels, as is the case with a fish reflecting <2% of an already dim source (i.e., a bioluminescent flash, lure, glow, or searchlight), against the black deep-sea background, the model predicts that the sighting distance is proportional to the square root of the number of photons being reflected back to the viewer.  Using this relationship, we find that reducing skin reflectance from 2% to 1% reduces sighting distance by 29% and that decreasing further to 0.5% or 0.05% reflectance reduces sighting distance by 50% and 84%, respectively.  Because visual predators typically search a volume of space, and this reduction in sighting distance is linear, the camouflage benefits of ultra-black skin may be even greater than the reduction in sighting distance calculated here.  Given the small size of the fishes studied here, it is likely that predator-prey interactions occur over short distances, where even small differences in sighting distance can have meaningful effects on interaction outcomes.

I've read that we know less about the abyssal regions of the ocean than we do about the surface of the Moon.  I don't know if that's true -- it's a little hard to quantify what we don't know about something -- but what's certain is that the deep ocean harbors some astonishingly weird creatures.  I'll end with a quote from H. P. Lovecraft, in whose writings the ocean represents everything that is dark and mysterious about the universe: "But more wonderful than the lore of old men and the lore of books is the secret lore of ocean...  The process of delving into the black abyss is to me the keenest form of fascination."

*************************************

This week's Skeptophilia book recommendation of the week is about as cutting-edge as you can get, and is as scary as it is fascinating.  A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution, by Jennifer Doudna and Samuel Sternberg, is a crash course in the new genetic technology called CRISPR-Cas9 -- the gene-editing protocol that Doudna herself discovered.  This technique allows increasingly precise cut-and-paste of DNA, offering promise in not just treating, but curing, deadly genetic diseases like cystic fibrosis and Huntington's disease.

But as with most new discoveries, it is not without its ethical impact.  The cautious are already warning us about "playing God," manipulating our genes not to eliminate disease, but to enhance intelligence or strength, to change personal appearance -- or personality.

A Crack in Creation is an unflinching look at the new science of gene editing, and tries to tease out the how much of what we're hearing is unwarranted fear-talk, and how much represents a genuine ethical minefield.  Doudna and Sternberg give the reader a clear understanding of what CRISPR-Cas9 is likely to be able to do, and what it won't, and maps out a direction for the discussion to take based on actual science -- neither panic and alarmism, nor a Panglossian optimism that everything will sort itself out.  It's a wonderful introduction to a topic that is sure to be much in the news over the next few years.

[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.