101 Interesting Things, part fifty-seven: Color Vision

A long-standing question in philosophy is whether the red I see is the same as the red you see.  The engineer's answer is that of course it's the same wavelength, and in accordance with the tradition of engineer answers, this is technically accurate but supremely unhelpful.  However, there is an answer, and that answer is clearly not, sometimes.

Pictured:  BULLSHIT.  (Not really.  Image found at Quora.)

For one thing, some people are colorblind.  But it gets so much cooler, and so today I'm writing about color perception!

You may have heard of the rods & cones in our eyes, and the short version is that rods help us detect brightness while cones help us detect color.  Rods are older, evolutionarily speaking, and much more responsive insofar as they take fewer photons to activate.  But cones, in helping us see color, allow us to distinguish predators among busy backgrounds and detect the ripeness of fruits.

Also found on Quora, but for a totally different conversation.

Interesting Miscellanies which You Prolly Know but Maybe Not

Most human beings are "trichromatic," having three kinds of cones:  red, blue, and green.  These respond, logically enough, to those corresponding colors of light.  This means that the only reason the RGB breakdown works is because it corresponds to our machinery, not because that's how anything "really" is.  But in some people, one of those sets of cones doesn't work, and they can't distinguish colors so well.  And there is of course more to it than that, but most people know about colorblind folks and it gets way more interesting than this so we are rolling right along!

On the opposite end of the spectrum (so far) are tetrachromats, people who have four kinds of cones in their eyes and can see not 33% more colors (as one might expect), but many times more colors than us measly trichromats.  This is because tetrachromacy doesn't "just" tack on another "kind" of color, but adds another dimension of color.  So on top of all the R values that can be mixed with all the G and B values, there's a fourth set of values that can be mixed with all of the previous.  But there's still more interesting to go!

The mantis shrimp sees our two to four color receptors, and raises:  they've got twelve to sixteen color receptors, on top of each eye being trinocular and thus independently depth perceptive.  Moreover, they can tune some of these receptors at will, and I don't even know how to imagine that twist on this thing I already can't imagine.  The mantis shrimp's eyes are truly a thing to behold, and I really wanna know what it's like to have them, and The Oatmeal made an amazing comic about it so just go read.  But even the mantis shrimp has to take a backseat to the very most interesting bit about color vision, and how we know sure as dammit that some people's red isn't the same as other people's red.

The Most Interesting Part of All!

Color perception is also influenced by culture.  Yeah, yeah, talk about the wine-dark sea and hair being compared to blue stones in Ancient Greek literature all you want, but this is some present-day go out and check now science.  Sadly, the video is now down, but it was explained in a BBC program and the episode was entitled "Do You See What I See?" (because of course it fucking was).  So some scientists found a tribe called the Himba and investigated their color terms and then devised a test:  show twelve swatches of color in a circle, eleven of which are identical, but one of which is different by a small but measurable RGB value.  We'll circle back after a brief tangent.

Us Westerners, with our internet and fashion industry, have pretty regular color terms (among present-day Western cultures, that is); this leads us into the trap of thinking they're objectively real and universal.  Our science of color perception has noted that cultures first develop terms for black and white, then red, then yellow (just like the TooL song), and so on; this leads us into the further trap of thinking that other cultures' color terms are deficient or primitive when they differ from ours.  But it turns out that other cultures can have color terms just as nuanced as ours but still different.  We can test this because we can make objectively different RGB values and then interrogate people for their subjective color distinctions.  I don't mean like Randall Munroe's color survey where clearly different colors are given the same name, I mean when actually different colors are perceived by us as the same color.

Not this, in other words.  But this:

(Top image from xkcd, bottom from PetaPixel's write-up of the documentary.)

Getting back to aforementioned test:  the image on the right has one swatch that's slightly more blue than the others, and the image on the left has one swatch that's slightly more yellow than the others*.  I bet you, being an Internet Person, are able to quickly & easily distinguish the odd one out on the right, but not on the left.  However, the Himba people of Namibia are the reverse from us:  they are able to distinguish the left set just as quickly & reliably as we can the right set, but they guess on the right set just as unreliably as we guess on the left set.  This is because the Himba distinguish more greens/yellows than us, but we distinguish more greens/blues.

Go ahead and take another look at those circles above, if you haven't already checked out the note below.  If you can't tell which one is different, SPOILER ALERT it's the same position in both circles.  /SPOILER  If you try real hard, you might be able to see the difference, now that you know - but would you really bother to single out that one square if asked whether they were all the same or if one was different?  If someone told you that the squares on the right looked all the same to them, would you say OK or would you call them colorblind?  In a way, this should be no more surprising than the fact that fashion industry professionals distinguish more colors in general than most of us (how many shades of grey do you really need, without a professional reason for training yourself to distinguish them?).  But the fact that the Himba so easily distinguish the left circle while having such difficulty with the right tells us, for sure, that what we see as blue they see as green as the rest of the circles - and vice versa for the circle on the left.

Age-Old Philosophical Problem:  solved!  We don't all see the same colors, it's influenced by a lot of things, from biology to culture.

Notes:

* - SPOILERS IF YOU'RE TRYING TO SOLVE IT YOURSELF!  I went & tested the RGB values, and it's a little disappointing because the "basic" green swatches are all 78/186/12, the blue one is 36/194/233, and the yellowish one (same position on the left) is 96/192/4.  Calculating the differences between them, the blue one is considerably more different than the others are from each other.  I went and made one that was "bluish" by the same numeric amounts as the yellowish one, and it didn't look very much different (and I also knew which one it was in advance, making the difference more noticeable to me).  But I was also able to distinguish the yellowish one, because I looked at the one on the right and then on the left and thought it was in the same position, but then I thought maybe it was just an after-image, so I looked at the one on the right and then turned the screen and looked at the left one, and the same one (now in a different position) looked different, so I figured I was right.  Then I tested them and I was vindicated, Hooray The End.

101 Interesting Things, part fifty-five: CRISPR

I don't have much by way of an intro for this one, so let's just say that CRISPR (pronounced "crisper," like the veggie drawer in your fridge) is the shit.  If you wanna watch a video, here's Kurzgesagt (whose channel I of course recommend for a million things) on genetic engineering, with a substantial segment on CRISPR:

Don't let the cutesy animation fool you, these guys rock the house.

John Oliver also did a show recently about CRISPR that reminded me how cool it is & how much I wanted to write about it.  His segment is really quite informative about the social context of it, but today I'm gonna bite into the nuts & bolts a bit.

Transphobia Busting #1: The Myth of Biotruth

"It's just a fact."  From Assigned Male Comics.  (Updated.)

The idea that trans folks are irrevocably the sex assigned at birth is a myth, and a transphobic one at that.  The fact is, "biological sex" is a social construction; but to understand why this is, we'll need to go beyond high school biology.

There are two ways to demonstrate this:  the mosaic theory of biosex in particular, and the social construction of knowledge in general.  Wait, three ways:  a YouTube video of someone explaining the core concepts!  Riley J. Dennis has made two such videos, the latter of which clarifies and expands on the former:

Trans women are not "biologically male," by Riley J. Dennis.

Male and female are binary, but people aren't, by Riley J. Dennis.

But if you're like me, you can read faster than people can talk, and you might be at work and thus unable to listen to a video, and you might want text that's machine-searchable and copypastable.  That's why I'm here!

The Mosaic Theory of Biosex

We pretend most of the time in common parlance that biological sex is one objective and easily decidable characteristic of a person, but this is not so.  The concept of biological sex, as used by biologists, is actually composed of five completely different things:  chromosomes, genitals, gonads, hormones, and secondary sex characteristics.  Gender has all these in addition to gender identity, gender role, and erotic preference, but these are subjectively experienced and performed, not objectively measurable - interestingly, it also means that the criteria of biosex are part of gender taxonomy.  While the components of biosex are objectively observable facts, lay folks have this annoying habit of pretending A. they all go together (they don't, that's an erroneous oversimplification), B. they're supposed to go together (they aren't, that's bionormativity and it's dumb), and C. they can thus make valid inferences based on a quick glance on the street (they can't, but they rarely get corrected so the misconception persists).  Let's take it by the numbers!

Chromosomes are what a lot of people lean on when stating "just the facts":  that XX is female and XY is male.  The reality is not that simple.  In brief, people can be genetically XXX, XXY, X, or even XY and externally female, or XX and externally male.  Moreover, while conditions such as infertility can result from such chromosomal arrangements, they don't always:  there is a case of one XY female who gave birth to an XY daughter, which shows that the condition of being XY and female is unknowably prevalent without the costly method of at least karyotyping a huge number of people.  While all known cases of XX males are linked to infertility, these individuals were only tested as a result of said infertility, which means that any fertile XX males could easily go their whole lives without karyotyping.  The bottom line is that you just can't determine someone's genes by external observation, even if those people are cisgendered.

Genitals are externally visible, but sometimes ambiguous.  They are also the primary means of assigning a baby's sex at birth:  for a long time, doctors decided that an "acceptably long phallus" meant "male," and anything else was "female," because it's easier to give someone a mostly-working vagina than an even partially-working penis.  In the 20th century, when such cases arose, doctors would approach the parents with heavily loaded language and say that there was a complication that would result in social difficulties later in life, but there was a medical solution!  Let us do surgery on your kid, and they'll be fine.  (Source:  lecture notes from Sex, Values, and Human Nature, taught by a professor with joint appointments in biology, philosophy, and WGS.)  The doctors would then attempt to surgically normalize the infant's genitals, sometimes with follow-up hormone prescriptions without the patient's knowledge or consent.  Sometimes this went fine, but sometimes it went horribly wrong, as in the case of David Reimer*:  a botched circumcision led to doctors recommending vaginoplasty and hormones, which the parents accepted, and later in life David strongly identified as male and transitioned to reflect his identity; due to a number of issues, however, he ultimately committed suicide.  The point is that often such birth determinations need to be later overturned, so genitals are also out as sole determinants of sex.  Moreover, due to intersex conditions and surgical procedures, you simply can't tell what someone's genitals are without seeing them naked anyway; you have to guess, and while you'd be correct a large percentage of the time, it's still a guess and you can't tell when you're wrong without further examination that would constitute a huge privacy violation.  In other words, you assume and almost never get your assumptions corrected, so you have no idea how often you're wrong.

Gonads are the sex-cell-producing glands (such as testicles and ovaries) that are needed for reproduction.  These are sometimes streak or infertile, though, so they are also not a foolproof guide.  Additionally, you cannot tell the presence or state of gonads simply by observing someone on the street, and most people never get their gonads checked in any but the most cursory of ways, unless some issue comes up that requires such a check.  The point here is that, while gonads typically develop in certain ways, there's no deriving normativity from these bare statistics (which remain largely unknown due to the cost and non-necessity of diagnostic procedures) without smuggling in a whole pile of values that will predetermine such analysis.

Hormones are molecular messengers in our blood and other fluids that can do all kinds of things.  In humans, males typically have high testosterone and females typically have high estrogen.  However, these cannot be measured except through bloodwork, which again isn't free or common without a need to investigate**.  Women with PCOS report feeling crappy in ways that sound lots like gender dysphoria, and low testosterone predicts depression in men.  I've read anecdotes about similar dysphoria-like symptoms in cis people who take hormones for medical reasons unrelated to gender identity, and about rampant self-harm and suicide in female Soviet athletes injected with testosterone in the 70s and 80s, but haven't yet been able to turn up citations on those (will update if/when I do).  The point being that, to all indications and the best of our ability to tell so far, it looks like a mismatch between hormones and gender identity can cause problems, and transition is the best and only recognized treatment for resolving this mismatch (at least, according to the American Medical Association, American Psychiatric Association, American College of Physicians, National Association of Social Workers, Royal College of Physicians, and National Health Service - among others!).

Secondary sex characteristics are a pile of traits like facial hair, Adam's apple, muscle mass, body odor, and so on.  Quite frankly, these are a complicated pile and while they're affected by hormones, everyone's a shuffled mish-mash of 'em.  Moreover, on pretty much every single such trait, there is more variation within each group than between both groups:  e.g. men on average tend to be taller than women, but most men and women are in the same height range.

The tiny distance between the bell tops is just obviously more important than the massive

overlap between their bases and their overall extent - right?  From Perry Street Palace.

The point is that while general trends exist and are measurable, they're not useful in determining individual status.

Putting it all together, if you were to draw a line down the center of a piece of paper, and put male-typical biotraits on one side, and female-typical biotraits on the other side, you would have a whole pile of biotraits that could actually go either way.  Any trait a cis woman might have, another cis woman might not have, and a cis male might also have. And vice versa:  any trait a cis male might have, another cis male might not have, and a cis female might also have.  Some cis women are born with XY chromosomes or ambiguous/atypical genitals; some don't have a uterus, ovaries, or breasts; some have never menstruated and won't give birth; some have thick facial/body hair, large frames, big muscles, or high testosterone & low estrogen; some look androgynous or like cis men; some take hormones or get plastic surgery to improve their quality of life; some are even raised & socialized as boys, or new info comes up to make doctors rethink their birth sex days-to-years later.  In other words, none of these traits "go together," it's completely normal for every person to be a shuffled mish-mash of them.

The simple fact is, there is only one thing that all cis women have in common, and that's that they identify as women.  Any cis woman might have any number of the above conditions; trans women just have the misfortune of having more of them than average (some cis women have more than some trans women, though!).

If you're gonna say trans women are biomales, then you have to say why they are ("they just are" doesn't count); that reason will necessarily bring a lot of cis women into the biomale category (and cis men into the biofemale category) as well; this is an absurdity, so you have to do something to resolve the absurdity.  You can reject the idea that trans women are biomales, or you can decide there's a special rule that only applies to trans people, thereby engaging in special pleading just for the purpose of excluding trans women (i.e. textbook transphobia).

The Social Construction of Knowledge

The very idea of biosex is a social construct.  Importantly, "social construct" doesn't mean "total BS," it just means that humans decided where to draw dividing lines, and we're not "cutting nature at its joints."  Nature doesn't have joints. Also, everything we care about is a social construct as well, so it's not a knock, just a fact: we decided that certain differences were important enough to warrant an ontological distinction (i.e. "this difference makes a different kind of thing, not a different example of the same kind of thing").  These distinctions are very useful all the time, but they are made, not found. In summary: differences are found in nature, but all distinctions & categories are cognitive inventions.

So let's just take the category "human" as primitive ("human" is also a social construct, but we're not gonna worry about that right now).  We've got a pile of humans, all the humans who ever have or ever will exist. They have differences, but so what? These differences don't matter to us right now.  But then you say, "We should actually make two piles out of this one, and call them Male and Female." Like, why? Why do we need this distinction? Whatever reason you give to motivate the distinction, that makes it motivated reasoning ("Well, this is what it takes for reproduction to occur." OK, so you're reproductively motivated - but why is that important?). We could pick any criterion we wanted to divide people into piles, the list is literally endless.  So that's Problem Number One: any distinction is inherently motivated reasoning, and therefore not impartial/objective reasoning.

Moreover, whatever trait(s) you do pick to make the distinction, just aren't gonna line up cleanly with how you want the categories to go (see the mosaic theory of biosex, above).  You're going to drag some cis women into the biomale pile as an inevitable consequence of trying to get all the trans women into it. There just isn't a single trait or group of traits that will get all the trans women, and only the trans women, into the biomale pile.  You can't pick "transness," because we haven't even made our "male and female" piles yet, so there's no cisness or transness to do that with - in other words, sex comes ontologically before cis or trans, and thus has to be decided without referencing any categories we make later.  This is Problem Number Two: our dividing lines can't be made clean, no matter what we do, because everyone's a shuffled-up mish-mash of traits.

Finally, we can draw up these distinctions however we want (and quite frankly, we're going to get arbitrary if we're gonna decide all cases; picking which cases to decide or not is also arbitrary; and ultimately, even deciding to make any decision at all is also arbitrary).  So let's be trans-inclusive, because trans folks are people too. Oh, you don't want to be trans-inclusive? OK, that's transphobia. If you say, "Well, women are supposed to be this way," stop right there - says who? There is no "supposed to," that's imposing normativity on nature; we're just talking about what is, there is no "should."  Here we find Problem Number Three: there's just no Platonic standard to appeal to, we have to decide and monitor our motivations in doing so, without appealing to normativity in the process.

The bottom line here is that any way of deciding what kinds of things exist and how to group them (i.e. "ontology") is going to be necessarily motivated at root, so we have to decide what we let motivate our decisions.  We can go with permissive and inclusive ontologies if we want to be permissive and inclusive; saying No We Have To Go With THIS Ontology And It Excludes Transes Sorry I Don't Make The Rules It's Just A Fact, is plainly and obviously transphobic, because you're making a choice and then insisting that everyone has to make the same choice as you, and it's perfectly clear that you're making the choice that way because you don't want trans women to count as "real women."

With acknowledgment to reddit user tgjer's Master List of Trans Health Citations.

Notes

* - I am reluctant to use Reimer as a political football, however the case is simply too instructive and concrete to ignore.  As Reimer's case was used in his lifetime to validate the malleability of gender, I feel that undoing that damage by working against those misconceptions is a worthy purpose to which his legacy may legitimately be put.  Thus, Reimer joins the uncomfortable list of Inherently Problematic Yet Socially Invaluable Knowledge, alongside the likes of Henrietta Lacks, the Tuskegee syphilis experiment, and the Milgram obedience experiments.

**I, however, did need to get bloodwork done when I got my hormone consultation, and as it turns out my testosterone was way lower, and my estrogen way higher, than a typical male's.  While I was hormonally closer to a male than a female, I wasn't really clearly either; and as my dysphoria significantly reduced on starting hormone replacement therapy (HRT) and then went into remission after 18 months, as well as significant reduction in my already mild bipolar tendencies that multiple regimens of antidepressants and mood stabilizers exacerbated, I call that a winning outcome.  Hormones are part of biology, and so hormonally I am more female-typical, and in this respect I am biologically female.

Transphobia Busting #0: Grand Central Station

Being a good Social Justice Warrior, I occasionally wade out into the trenches of the intertubes to do battle with small minds and big, uhh, bigots alike.  I mostly try to fight my own battles (women, LGBT, atheism, etc.), though I do occasionally call-in those I know for problematic statements out of my field, and recently I did a whole bunch of Arguing on the Internet over a transgender greeting card.

The... offending? card.  From Ladyfingers Letterpress.

I found myself trotting out the same handful of arguments against the same handful of misconceptions, so I thought it would be useful for future arguments to have a series of posts I can link instead of boiling copypasta from previous comments.  Handily, I also ran into the following comic at about the same time.

This is true, but requires unpacking.  From Assigned Male Comics.  This comic has

been updated (see link), but this is what I shared and what I'm arguing, so there.

I shared it to the Faceborg and found myself arguing all over again, so I'm going to tackle the following transphobic tropes in a short series of posts:

1. The Myth of Biotruth
2. I wouldn't date a trans person.
3. Isn't it deceptive? and, Isn't it homophobic?

Links to follow as the posts are complete.  Wish me luck!

EDIT:  We are wrapped up and all done!  Links are updated, and if you're reading this in the next hour, the final post will drop just before midnight.  I may or may not update this later with new installments in the event of other trans-related controversies, we'll see.  Cheers!

Lineages and Stuff!

I started writing another chapter in Tooth and Claw, after tacking on another half-page to the last chapter which didn't quite feel finished, but I got distracted.  Distracted by what?  Well, a few things.  There was this comment thread over on Daylight Atheism, and there was a Facebook conversation that I got tied up in, and another Facebook conversation that resulted in an email.

For those who might be wondering, I follow the "Can I Punch You in the Face?" rule for Facebook.  This rule follows the question, "Have I ever had the opportunity to punch you in the face?"  If so, we can be friends on Facebook.  If not, we cannot be friends on Facebook.  If I've been able to punch you in the face, and wanted to friend you on Facebook, I would have done so by now.  Double-promise.  :)

Anyway.

The tying-up-Facebook conversation was with a Libertarian friend of mine, and he's kind of an asshole, so I'm not gonna bother with that.  But I have hope for him, because he is ruthlessly logical!  (And yet I despair, because his fundamental premises are so flawed!)

The e-mail conversation ended up being to one Doctor Dick Dawkins (the triple D sounds so much better, doesn't it?), and I'll just post it here in its entirety, because I should be getting to bed soon and... well, really, I've grown into a responsible adult and so that's reason enough.  Right?

101 Interesting Things, part forty-nine: Silk

I have an endless fascination with macroscopic properties that are explicable in terms of microscopic properties, dating back to high school when I learned why the structure of water makes it a universal solvent, why the alignment of iron can result in magnetic fields, and where pH comes from.  (When I asked my chemistry teacher, "What does pH mean, though - like, what's the thing that number's based on," she responded in a monotone, "Negative log of the hydronium ion concentration."  After about ten seconds of goggle-eyed musing, I understood exactly what that meant and have never forgotten it.)  It's also what caused electricity to be irreducibly magical to me, until I came to see voltage as a kind of "electrical pressure" - then, like, a million phenomena and failed experiments all clicked into place and I felt like a dummy... but an enlightened dummy!

So it should come as no surprise that one of my favorite books of all time is Napoleon's Buttons:  17 Molecules that Changed History, by Penny LeCouteur and Jay Burreson (well here's an interesting tidbit:  my copy has this cover design, but that subtitle).  The sixth chapter is on silk and nylon, nylon being developed for the purpose of being an artificial silk.  Other interesting tidbit:  in technical chemistry terms, "artificial" and "synthetic" mean two different things; "synthetic" means "laboratory-produced but chemically identical," whereas "artificial" means "not the same thing but has the desired properties" regardless of its method of production.  So "artificial sweeteners" are "fake sugar"; they're not really sugar, they just do the thing we want sugar for; whereas "synthetic vitamin C" is the genuine article, real ascorbic acid that happens to have been synthesized in a lab instead of being derived from a plant.  (This difference is articulated somewhere in the book, but at least four of the seventeen chapters deal with the difference and I refuse to track it down.  I've been procrastinating long enough and only need some pictures, anyway, because the rest of the important information is just in my head.)

Anyway.

Cross-post: Adventures in Taxonomy!

One of the unwritten problems with Tabula Rasa was that I kept wanting to interject little bits of the supernatural, but the whole blessed point was that the world was completely mundane.  So I sloughed them off to another story I had been thinking of which was legitimately about the supernatural.  Eventually, I had so many fragments and ideas shoved over there, it started becoming a story in its own right.  I know a story's good when characters I give placeholder names get names of their own - I'm famously bad at naming things, you see - and now I've got so much that I can't not write it.

First, though, I have a bit to write about silk for 101 Interesting Things.  And before that, I've got this humorous little bit that I pulled off from my Playskool blog.  The bit about the Wheel of Death waxes fantastical, but the rest of this is a real conversation that I really had in real life.  No joke, it's almost literally word-for-word, because I wrote it all down right after it happened (and, when I went wiki-walking, even jotted down notes on the story so far).  Anyway, enjoy!

"There are only three things in the sea:  fish, amphibians, and mammals.  OK, maybe a couple plants."

101 Interesting Things, part forty-eight: Pyura chilensis

Let's have ourselves a little climb up the family tree.  In the kingdom Animalia, phylum Chordata, you'll find the class Ascidiacea.  Ascidians are the sea squirts, immobile filter feeders who sit in one place and just process whatever floats by.  You know your sea squirts, right?

You've got your ravers...

Your psychedelics...

101 Interesting Things, part forty-five (b): Blood - Hemoglobin and Homeostasis

"Hemoglobin is the key to a healthy heartbeat."

- Placebo, Haemoglobin

Blood - vertebrate* blood, at any rate - is red because the erythrocytes that float in plasma are red. The erythrocytes, in turn, are red because of all the hemoglobin in their cytoplasm. It's chock-full of the stuff. In the diagram below, the four green wire-frame looking bits (as opposed to the red and blue ribbon-looking bits) are the ferrous heme groups that bind up the oxygen you breathe into your lungs:

source

Oxygen diffuses into your red blood cells through the alveoli of the lungs, where each of those heme groups grabs an oxygen molecule. It's easy to do, since oxygen is fairly plentiful in the air we breathe. That may not seem like a whole lot, but it increases the amount of oxygen your blood can absorb by about seventy times, since otherwise oxygen could only dissolve into your plasma as a gas. Then, as your blood courses through your body, the lack of oxygen causes the iron atom in each heme group to lose its grip on the oxygen molecule it's holding, and the oxygen diffuses into nearby cells where it fuels the chemical reactions that drive you. That's... really all it is! Just pressure. Lots of chemical reactions, it turns out, are more like making soup than they are like building a machine, and the body's urgent need for oxygen in every cell means that a quick and dirty solution like this is all it takes (no fancy-pants calcium ion pumps or anything).

Of course, hemoglobin isn't the only solution to this problem. Molluscs and arthropods use cuprous hemocyanin, which does the same thing but has way cooler color-change action. See, deoxygenated blood is dark burgundy in color, whereas oxygenated blood is a more vibrant red. When hemocyanin is deoxygenated, it's colorless - but when oxygenated, it's blue. Look at this crab:

source

To be fair, hemocyanin bonds a little stronger to oxygen, which is what makes it so good for the invertebrates that use it, because they often inhabit oxygen-poor environments. On a related note, carbon monoxide bonds much stronger to the heme groups, rendering them useless because it never leaves, and this is why CO is such a deadly poison. Other solutions to the "Gee, I need oxygen in my blood" problem include hemerythrin, which is pink when oxygenated and colorless when deoxygenated, and the Christmas-themed chlorocruorin, which is red when oxygenated but green when deoxygenated.

OK, enough about other kinds of blood, back to your blood! After your erythrocytes have dumped their truckload of oxygen into your hungry hungry cells, they pick up the carbon dioxide to carry it to the lungs for exhalation. This is done in three ways: about 7% of your waste CO₂ is dissolved directly into plasma, 23% combines with hemoglobin, and a whopping 70% is transformed by carbonic anhydrase (which is in your erythrocytes' cytoplasm) into carbonic acid. The Alert Reader who is passing familiar with chemistry will notice that carbonic acid dissolves in water by separating into a negatively charged bicarbonate ion and a positively charged hydrogen ion (or, as physicists are wont to call it, a proton). The Alert Reader who is passing familiar with chemistry will also notice that free-floating protons in water tend to result in hydronium ions, and the negative log of the hydronium ion content is what is measured when we refer to "pH". Here is a chart showing what happens when your blood pH gets outside the narrow range of 7.35-7.45 that I mentioned when we spoke last:

source

The Alert Reader who is passing familiar with Greek will notice that everything outside of Normal ends in "-osis", which means problem (loosely translated). So how does your body fastidiously avoid such problems? Well, in the first place, it's not like all your cells take in oxygen at once and then pass off carbon dioxide all at once. That would just be silly. But your body is always metabolizing, all the time always until you're dead, and so it needs to keep a tight rein on your blood pH as you go through your varying levels of activity.

Blood is slightly alkaline, and your bones are basically load-bearing mineral deposits, so that helps at least a little bit (Fun Fact: consuming too much animal protein in relation to vegetable protein has been implicated in bone mass loss in females!). Short term pH imbalance can be corrected by altering respiration: expelling more CO₂ will increase the proportion of CO₂ dissolved in blood (less carbonic acid means more alkaline blood), and holding on to more CO₂ will increase the proportion held as carbonic acid (or H+ and HCO₃-) and increase acidity. In the long term, your kidneys respond by excreting the leftover acid or base that builds up in your bloodstream, and also regulating the amount of buffering ammonia in your blood.

Your blood also helps regulate your body temperature through the clever application of plumbing. Heat is generated in various organs such as the liver and the brain (even thinking is exothermic!), and blood acts as a coolant to help you avoid overheating by absorbing some of the heat and bringing it to the heat sink that is your skin. In addition to sweating, your body sheds excess heat by expanding its arterial walls, increasing blood flow to the capillaries near the surface of the skin where the heat escapes into the atmosphere, or at least into your sweat (if the surrounding air temperature is higher than your body temperature). When you need to conserve heat, your arteries constrict, reducing blood flow to the skin and extremities to conserve heat and thus maintain core body temperature. This is why the cold will often make you numb and pale: your thoracic cavity needs all the heat it can hold on to, and the rest of you is somewhat more expendable. Note that this is distinct from frostbite, which results from ice crystals puncturing cellular membranes and causing cell death (this is why frostbitten tissues are kinda gelatinous when thawed, and one of the key hurdles for cryonics to overcome in the quest for legitimacy).

OK, oxygen transport, acid-base homeostasis, and thermoregulation - check! Tune in next Wednesday when I chatter on about the army of your immune system!

* - There just had to be an exception, didn't there?! The crocodile icefish does not use hemoglobin, and is the only vertebrate known not to do so. It lives in sub-zero seawater where it can absorb all the oxygen it needs right through it's goddamned skin. Fuckin' icefishes have it so stupid easy.

101 Interesting Things, part forty-five (a): Blood - An Overview

Leviticus 17:11 says, in part, "the life of the flesh is in the blood". This is one of those things where the Bible actually gets it right, but they really had no idea how right they were. It doesn't take any great leap of creativity to notice that draining the blood from an organism is, by and large, fatal to said organism: massive blood loss is so consistently fatal because blood does so goddamned much for us in the first place.

Blood carries oxygen, food, and water to living tissues; it carries waste to the kidneys, liver, and lungs; it maintains the police presence of the immune system and carries vital hormonal signals all throughout the body; it even has pressurized hydraulics and helps regulate body temperature, all within a narrow range of pH values (a tenth of a point, between 7.35 & 7.45). Your body is basically a sac for your blood, the universal fluid that ties every part and function together. They Might Be Giants explain it in broad strokes and easy language in The Bloodmobile:

They Might Be Giants - The Bloodmobile from They Might Be Giants on Vimeo.

In many ways, your life revolves around your blood: your bones make erythrocytes in their marrow, and your tendons (which technically aren't vascularized) hold your bones together in ways that (usually) don't impinge upon the flow of your circulatory system; your circulatory system, in turn, carries blood to the various organs you use to maintain the fuel supply within your blood, including the brain and heart with their minute-to-minute demand for oxygen; your digestive tract is a tube within a tube, busting up what you eat at the molecular level to harvest the aforementioned fuel before dispensing with the unnecessary bits; and your skin holds it all in and keeps unwelcome elements out.

Blood's very ubiquity made this an unusually research-intensive entry, and there's so much interesting stuff that I want to take it by parts. This weekend - and since I'm not spending all my time reading about blood, I'll actually have time to write about it, so it will actually be this weekend - I'll write about blood's role in respiration and homeostasis, ferrying oxygen and carbon dioxide hither & yon, and regulating pH levels & body temperature. Next Wednesday, I'll write about the immune system, which I would normally give its very own entry except for the fact that it all kind of takes place within the blood. And the following weekend, I'll talk about blood technologies and diseases, because they are also fascinating. Stay tuned!

Epistemology and Spiders: This is how it should be done

OK, so assessing and revising the contents and standards of one's knowledge has nothing to do with Mindless Self-Indulgence - if anything, it's mindful self-restraint. But one of my recent forays into the world of Science Blogs handed me a case-in-point so neat and pat that I just had to share.

A bit of background: there's this wonderful little program called Before the Dinosaurs: Walking with Monsters (buy!) which goes through the history of life from Anomalocaris to Lystrosaurus. It's just awesome, and you should watch it. One of my favorite parts of that program was the puppy-sized spider, mesothelae, which lived at a time of eagle-sized dragonflies because the atmosphere was so oxygen-rich that giant bugs could get away with enormous bodies and simple respiratory apparatus.

Now, I love spiders. I really do. They're nature's ninjas, out-ninjered only by certain species of squid and octopus (ninjas of the sea). So a spider the size of a small dog is, like, my new favorite fantasy pet. Excluding giant spider-steed, of course (what it loses in ninjery, it more than gains in bad-assitude). OK, now we're good. My point is that I was very fucking excited to hear about this mesothelae, so excited that I went around telling people about it for weeks.

Fast-forward to last week, and I see this Laelaps headline link while catching up on Pharyngula: Megarachne, the Giant Spider That Wasn't. My first thought: "Ooh, spiders!" Second thought: "Aww, fake spiders?" So I click through and read the whole thing, and as it turns out, Before the Dinosaurs was originally slated to include megarachne, but during production it was discovered that the giant spider wasn't a giant spider, but a sea scorpion. Well, shit on toast! But the show must go on, and so the BBC just re-cast mesothelae in the role that megarachne had been written to play and fudged a couple details (bah, details!).

If you're like me, then right about now you've got to have a tangled web in your head involving sense, reference, justification, and a couple theories of truth, all wrapped up in a package labeled, "D's beliefs about carboniferous arthropods". OK, now that I put it that way, you're probably not like me. But that's what was going through my head as I processed this article. Of course, sorting out that Gordian knot would be like trying to diagram one of Nathaniel Hawthorne's third-of-a-page sentences, so I took the Alexandrian solution:

"Huh. Looks like I was wrong."

Because at the end of the day, it doesn't really matter that a bleeding-edge breakthrough in paleobiology took a backseat to a deadline, it doesn't really matter that there was still a kernel of truth in it, it doesn't really matter how much I love the idea of giant spiders, and it doesn't really matter exactly what labels or confidence levels I had for this or that bit of belief. What matters is that I became aware of one instance wherein my picture of the world failed to match up with the best our investigations have to offer. So I fixed it, The End. As Carl Sagan wrote,

Science thrives on errors, cutting them away one by one. False conclusions are drawn all the time, but they are drawn tentatively. Hypotheses are framed so they are capable of being disproved. A succession of alternative hypotheses is confronted by experiment and observation. Science gropes and staggers toward improved understanding. Proprietary feelings are of course offended when a scientific hypothesis is disproved, but such disproofs are recognized as central to the scientific enterprise.
(The Demon-Haunted World, page 20)

So I was reading about this Jesus fellow the other day... or was it Krishna? Or Mithras? Wait, Horus! Or maybe even Moses... look, you see where this is going.

I don't think that argument suggests what you think it suggests.

Alvin Plantinga recently made an appearance roundabout my neck of the woods. My good friend came out from grad school to see him, so I kind of had to go as well. I mean, catching up with a buddy in grad school and picking on a 77-year-old theist? How could I miss out?

I pick on Alvin because I like him. He's a lively and affable guy in person, and really quite bright - even if he thinks that entities can be defined into existence. I just happen to think he's sadly misguided, and in an innocent enough way to justify paraphrasing The Princess Bride. Anyway, the good doctor's talk was on his evolutionary argument against naturalism, a pretty decent piece of reasoning that just so happens to cut against him in the particulars. If you don't feel like clicking through, here's the Fucking Short Version:

1. The probability that human cognitive faculties are reliable¹, given naturalism and evolution, is low².

2. If we accept both naturalism and evolution, and understand premise 1, then we have a defeater for the idea that our cognitive faculties are reliable.

3. If we have a defeater for the idea that our cognitive faculties are reliable, then we have a defeater for any belief we may come to hold with those cognitive faculties (including a belief that naturalism and evolution are true).

4. Therefore, we should not believe that naturalism and evolution are true, because they are self-defeating.

Conclusion: Therefore, fucking magic!

Notes:

1 - Weasel word!

2 - So what?! The Universe is a big place and rare things happen all the time.

OK, we've some unpacking to do here. As for that first premise, Plantinga leans on a quote from Patricia Churchland on the utility of truth for evolved animals: "Boiled down to essentials, a nervous system enables the organism to succeed in the four Fs: feeding, fleeing, fighting, and reproducing. ... Truth, whatever that is, definitely takes the hindmost." Plantinga uses this to develop his point by saying that natural selection can only work on behavior, not on beliefs (nevermind the fact that beliefs often inform behavior - seriously, don't mind this for now!), and therefore the truth value of this or that belief is irrelevant next to how adaptive or maladaptive the organism's behavior is.

This is, well, true. Natural selection simply can't act on what you believe independent of everything else. Plantinga goes to great pains to make this point. All other things being equal (which they never are, but still, we're ignoring that for now), the truth value of a belief is in fact irrelevant to the evolutionary process. To put his argument in more Cartesian terms,

"My evolved brain is not perfect, therefore it screws up. Because it's all I've got to work with, I might not be able to know whether it's screwing up at any given moment, because it might be screwing up right the fuck now. Therefore, I can never be 100% certain that I'm in my right mind."

I want to press Pause to let everybody know that I am with him so far. Really and truly (I just conclude that we must live with "less than 100% certainty"). Here's where things start to get real funny, though:

"Since I can never be 100% certain that I'm in my right mind, I might even be wrong about that. Because this uncertainty is self-effacing, I ought not to buy it. Therefore, I shouldn't buy the reasoning that brought me to this conclusion. Theists don't have this problem because we believe that our brains were purpose-built by God, so we can trust them."

Not joking! He says, "If my brain is evolved (i.e. not built by God), then I shouldn't trust it, even when it tells me that my brain is evolved; so I'll go with a belief system that ignores the problem of self-doubt instead." I mean, Alvin Plantinga wouldn't say that he's ignoring the problem, but that's what he does. Look, just because cars can break down doesn't mean that my car is broken down right now, and anyway you don't need to believe in Platonic Devices to avoid the uncomfortable possibility that your car might break down tomorrow. You can in fact believe something with 95% certainty and accept that one time in twenty, you'll be surprised. I mean, holy shit.

Enough cussing for the moment. I'm going to go right for premise 1 by granting it: given naturalism (i.e. not supernaturalism) and evolution (i.e. not IDiocy), the probability that my cognitive faculties are "reliable" in any strong sense is fairly low. Now, neither Plantinga nor I wish to speak of perfect reliability here; he even gives the example in his talk that if you ask five different witnesses about a car crash, you'll get five different stories (he says that their reliability is in the overwhelming agreement upon background beliefs that make their stories possible: the crash occurred on Earth and not Mars; the crash involved cars and not boats; cars drive on roads and not rainbows; blah blah blah). However, in order to achieve survivability, some reliability is necessary: bees need to apprehend reality to a degree in order to dance out directions to their cohorts, for example. So we're talking about a gradient of reliability here, really. He granted this during the Q&A session.

But then, that really gives it up, from his end. When we speak of the probability (P) of a degree of reliability (R) occurring in nature, given no supernatural input and a competitive environment, we no longer need to speak in terms of absolutes. Rather, we have freed ourselves to talk in terms of how reliable we need to be, how long we have to get there, and how lucky we're allowed to get along the way. Early on, the demand for R will be low, raising P (since lower Rs are more achievable). As time goes on, R can be refined, and in a competitive environment this will bring about ever-stricter requirements for higher Rs - so larger timescales also improve our P. Now I, for one, was born a piss-poor thinker, and I had to be educated rather heavily in the proper use of my gray matter - this education, in turn, was based on a long history of competitive educational systems in a world of scarce funding, and informed by a long tradition based on accumulating and revising knowledge.

So really, to get the R which I enjoy this very day, I only had to be born with enough R to be worked upon by something that was more or less evolved in its own right to do just that. And looking back before that in history, I mean, wow! People were nuts! They believed all sorts of crazy shit; Hell, we still do! Even within humanity, we see wild variance for R, from scientifically literate skeptics at one end to mental patients and uneducated children at the other. The reliability of our cognitive faculties is a fluid thing which can be honed or stunted; it can improve or atrophy over time.

Now comes the question, "How lucky are we allowed to get?" After all, homo sapiens is but one species among many on this teensy little rock of ours. Would it not stand to reason that at least one organism, with enough time, would develop enough cognitive reliability to improve upon it more or less exactly as we humans have in fact done? Plantinga's response was to ask, "Well, who's to say that it would be us?" Argh. I pointed out that whichever species did that would be the one to have these sorts of conversations, and then Plantinga said, "Well, maybe it's dolphins and they have the good sense not to argue about such things." Thank you, doctor. By this point, I had pretty much asked three questions, and things needed to be moved along. Ah, well. It was fun while it lasted.

This post was featured in the 52^nd Humanist Symposium.

101 Interesting Things, part forty: Cnidocytes

The C is silent, which may ease pronunciation. Cnidocytes are basically nature's single-use, single-cell harpoon guns. Not joking. Here, just look at this diagram:

source

OK, so yeah, that hair-trigger thing is called a cnidocil, and what it triggers is a load of calcium ions to surge into the main body of the cell. Then, thanks to the magic of osmotic pressure, water rushes into the cell from outside, turning the folded-in cell inside-out and propelling a tiny barb on a string into the offending organism at upwards of forty-thousand Gs. As you can imagine, these things don't come cheap: they're something of a pain to make, and so cnidarians (which, whaddaya know, are the things that have cnidocytes) also use chemoreceptors to detect whether or not they're dealing with a prey organism and then fire their cnidocytes in batches.

This is rather like a forward reconnaissance group determining that, yes, the enemy is here, and then a battery of artillery guns firing on the enemy position. Except that the forward-recon-group-slash-chemoreceptors are tasting the target to determine that they're the enemy. And the artillery-guns-slash-cnidocytes are hucking threaded needles full of poison really, really fast at the targets. Oh, and the gunners die after firing one shot. So it's really not like it at all, but now you should be picturing guys in camo licking their enemies, then a bunch of other guys in camo behind them hucking poisonous needles at the other side as they explode in death and organs (this may or may not be what I think of the army). Behold the power of imagery, and how I wield that power with something that might be like panache!

The point is that while we homo sapiens have refined the process a bit, jellyfish and anemones have been doing this shit for ages. Like, literally. Now I need to find something interesting that's not biology, before this turns into "Mother Nature Did it First: The Blog" while I'm not looking.

101 Interesting Things, part thirty-nine: Taste

In philosophical circles, the "what it's like" of this or that experience is called its qualia, or if you prefer large and impressive words to small and difficult words, its phenomenology. Philosophers have rather admirably tackled this issue, with some of the famous (read: "familiar to me") examples including Nagel's What Is it Like to Be a Bat? and Jackson's Epiphenomenal Qualia. Much has been made of the importance of qualia in philosophy, case in point being Jackson's paper where he uses the very subjectivity of experience to argue for epiphenomenalism. Thankfully, he seems to have come to his senses, though I'm not quite sure how he missed the problem with "epiphenomena exert no causal effects; qualia are epiphenomenal; Mary's quale of red causes her to say 'wow'." Whatever, I used to think that a man dying and coming back to life in three days was a noble sacrifice instead of a stunt; I can't really judge this guy for missing the glaringly obvious.

Speaking of the obvious, I think there's a rather easy example available to dispense with the weighty implications attributed to qualia - in terms of both what qualia might imply, and what we might disagree on when speaking of qualia. The Alert Reader will have guessed by now that this easy example is the sense of taste. And speaking of abrupt transitions, it's time for a biology lesson! We begin with the Wikipedia article, because it is clear and concise, and I doubt my ability to abstain from plagiarizing it anyhow:

Taste (or, more formally, gustation) is a form of direct chemoreception and is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons. In humans and many other vertebrate animals the sense of taste partners with the less direct sense of smell, in the brain's perception of flavor.

I want to make it clear here that we are talking about chemoreception, the sensing of chemicals. Not flavors. Flavors are the product of your brain, and they do not inhere in chemicals, but are rather the result of complex interactions between your neurology and what you put in your face. The quick & dirty breakdown is that your taste buds detect the molecular shapes of the things you eat (such as sugars, proteins, or alkaloids) or the presence of dissolved ions (acids are sour, salts are salty); then, nerve impulses are transmitted to your brain to tell it what's going on; then, you react to whatever it is that just happened.

This is what makes things like artificial sweeteners possible. You see, certain chemicals which do not occur in nature commonly (or at all) can trick your tongue into thinking that something is there which might not actually be there, just because they're similarly shaped in this or that way to the sort of thing that abounded in our evolutionary history. Case in point: aspartame. While the body still metabolizes it, aspartame is experienced by the body to be about two-hundred times sweeter than sucrose (though of a somewhat different taste, depending on who you ask), making its caloric content negligible for about the same amount of sweetness. Models of how sweetness works have grown in sophistication over time, the current model describing some eight reception sites and culminating in the development of lugduname, which is estimated to be some two-hundred-thousand times sweeter than sucrose.

Just in case we're not clear yet, let me say this in a different way: your taste buds are shape detectors and ion detectors which react with certain chemicals to send nervous impulses to your brain. The "taste" of this or that thing is the product of what your tongue tells your brain it is shaped like (or its pH value/alkali ion content). Seriously. Isn't that fucking weird?! And even weirder, there are substances called sweetness modifiers which temporarily but fundamentally alter the way sweetness is perceived, such as lactisole (which inhibits the taste of sweetness) and miraculin (which makes sour things taste sweet instead). I mean, whoah!

We were talking about qualia earlier, and now it's time to get back to that. I think that taste is perhaps the most vivid demonstration of the crowbar separation (thank you, Eddie Izzard) between reality and how we perceive it. Once again: shapes can be delicious, WTF. With touch, it's pretty easy to imagine sensations of pressure, wetness, or roughness being at least somewhat related to what's going on (with the possible exception of temperature - I mean, c'mon, rapidly vibrating molecules equals hot? Who comes up with this shit?). Same with perceptions of the visible wavelengths of light, or the audible wavelengths of sound. But taste? Give me a break! There just has to be some subjectivity going on here, because the "what it's like" is nothing like the "what it is"!

This also makes some of the debate about qualia seem rather silly. I'll briefly discuss two examples, first the analogical relationship between color-blindness and supertasting, then the inverted spectrum argument. I'll close with a quick Take That! directed at proponents of intelligent design, and a little treat for sticking it out through this interdisciplinary ramble.

First off, when we consider whether qualia are "the same" among different people, of course they're not. Nobody ever said they were, but when you consider that the colorblind see rainbows in a completely different way than most other people do, and that some people experience taste way more intensely than most other people do, then I think it becomes trivially easy to imagine that no two people experience the world in the same way. Even Epictetus was able to point out that two people can have wildly differing experiences of the same situation, and so it is not necessarily the world itself that causes us joy or suffering, but our attitudes toward it - what I would add is that a person may be just as powerless to change his or attitudes as to change his or her taste buds. Sometimes this can happen for no apparent reason, as with my early disgust and later love for mushrooms. Sometimes it happens due to experience, as with my aversion to light beer. Sometimes it doesn't happen no matter how hard you try: I will never be able to enjoy a resin spurge sandwich, because resiniferatoxin is so much more potent than capsaicin, it's not even hot any more (you just go into anaphylaxis and die).

With that in mind, the inverted spectrum argument is even easier to de-fang. For those who didn't click through (and I throw potholes all over the place, so I really don't blame you), the argument goes as follows:

1. Metaphysical identity holds of necessity
2. If something is possibly false, it is not necessary
3. It is conceivable that qualia could have a different relationship to physical brain-states
4. If it is conceivable, then it is possible
5. Since it is possible for qualia to have a different relationship with physical brain-states, they cannot be identical to brain states (by 1).
6. Therefore, qualia are non-physical.

Now, is it just me, or is the question simply beggared in premise three? I mean, if qualia could have a different relationship to one and the same physical brain-states, then of course they're not physical! Fuckin' duh! But this is exactly what is at issue. We see over and over again in the literature (Just look! Like, anywhere!) that when you change the sensory apparatus, you change the qualia. To a person who is relatively up on the neuroscience, while taste and sight vary greatly across the spectrum of human experience, the conceivability of two possible qualia X & Y for the same brain state Z is somewhere on the order of that for two possible diameters A & B for the same circle C. It's just that no two physiologies are perfectly identical (not even the same physiology at different points in time), so of course subjective experiences vary.

As for the IDiots, well, I'm just going to come out and say that ethylene glycol tastes sweet and is very toxic. So that's a poison detection failure right there. But let's not forget that to supertasters, a wide variety of totally healthy foods taste absolutely repulsive; and to non-tasters, a wide variety of potentially fatal substances taste perfectly fine. Oh, and how about the fact that the sense of taste is based primarily on superficial characteristics of molecular compounds, and is therefore rather easy to hack?

OK, so I'm done tying loose threads together for the night. Seriously, I got way too sidetracked while writing this post. I leave you all with the following cookie, as promised. This one tastes like tough decisions:

Click it!

101 Interesting Things, part thirty-six: Cordyceps, scourge of the jungle!

Cordyceps is one of my favorite kinds of parasite: a zombie parasite! That is, a biological zombie parasite, not a memetic zombie parasite (religion, nationalism, etc.). What do I mean by "zombie parasite?" I mean a parasite that overwhelmingly alters the behavior of the host, like rabies (which makes its host restless, vicious, and thirsty), in a way that makes it dramatically more likely to cause the parasite to spread. The common cold, influenza, ebola, these just straight up kill you (or get killed) and it's a pretty boring fight. But zombie parasites make you do things that you could imagine the parasite straight up asking you to do, and you say "Yes." Just like religion!

Check this out:

Footage from Planet Earth.

Cordyceps is a real monster, albeit a beautiful one. It can make floor-dwelling ants, which would normally spend their entire lives on or beneath the ground, climb. And it looks cool, too! Check out some of these sweet photos:

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Seriously: so awesome. But don't ever mutate! You can click on any of those "source" links for bigger (and more!) images, and you can also go here for even more shots. Great stuff!

101 Interesting Things, part thirty-four: Mimicry, Nature's Disguise Kit!

There's a whole lot to be said for doing your own thing, but sometimes it pays to be like someone else. As it turns out, there are some pretty cozy niches available for those organisms which are able to disguise themselves like other organisms. Take the myrmarachne spiders, for instance:

These guys are jumping spiders, but they waggle their legs like antenna, and I guess the ants buy it. But then, people have gotten turkeys to try to mate with socks on sticks... and then again, there's porn. But yeah, spiders acting like ants, infiltrating their society, and then eating them. It's like a nature's social predator. Awesome!

As it turns out, ant mimicry isn't exactly a "new thing," other bugs have been doing it for quite some time. Take Macroxiphus, a katydid that mimics ants in its larval stage:

And what do you know, but flies do it, too:

But it's not just ants that get mimicked. Check out Macroglossum stellatarum, a moth that mimics a hummingbird:

And that's not all that moths mimic, either; there's a hornet moth, and a wasp moth, too!

Podosesia syringae (ash borer) photo found here

These crazy moths don't just look like their role models, they also ape their behavior, such as flight patterns. The hummingbird hawkmoth moves like a hummingbird, and the hornet moth moves around erratically like a hornet when it's surprised.

And let's not forget the stick bug (which, I just learned today, actually makes a good pet!) and the leaf bug, the first two mimics I had ever learned about. But the top of the mimic heap, without a doubt, is the mimic octopus. This guy can mimic the shape, coloration, and behavior of over a dozen different animals! Check it out:

Further reading:
World's Weirdest Moths (or: Why Moths are Way Cooler than Butterflies)
Wikipedia's mimicry page

All uncredited photos taken from Wikipedia.