Sunday, June 04, 2006

We Have Always Been Posthuman

First, let me assure you that if you're an English scholar with a sufficiently postmodern focus, the title of this post is a riotous, riotous joke. See, it references Latour's We Have Never Been Modern and Kate Hayles' How We Became Posthuman! So funny. (This is what literature scholarship does to your sense of humor. Anyone who's still wondering why I took a break from academia, wonder no more.)

Anyway, the week's Big Duh award goes to Reuters for reporting that we may not be made up entirely of human cells. Anyone who grew up on Madeleine L'Engle is currently rolling their eyes and saying "uh, yeah, the mitochondria and the farandolae? Please." Even those of us who have refined our science knowledge past the first-grade reading level, and who know there's no such thing as farandolae, are probably pretty comfortable with the idea that mitochondria have their own DNA. We also know that bacteria have genetic material, whether or not they live in our intestines. So when we read about a TIGR researcher explaining to a reporter that "We are somehow like an amalgam, a mix of bacteria and human cells," we can almost hear the tone of exaggerated patience.

Still, the sheer volume of bacterial cells, and the ratio of bacterial to human DNA in some parts of our bodies, is pretty impressive. The digestive system, in particular, seems to be more microbe than man:
They [a TIGR team] compared the gene sequences to those from known bacteria and to the human genome and found this so-called colon microbiome -- the entire sum of genetic material from microbes in the lower gut -- includes more than 60,000 genes.

That is twice as many as found in the human genome.

"Of all the DNA sequences in that material, only 1 to 5 percent of it was not bacterial," Gill said.
What's not mentioned in this quote: the "so-called colon microbiome" was extrapolated from feces. So I'm not sure how they ruled out DNA from masticated critters, or how much human DNA they really expected to find. Clearly there is something about poop analysis that I don't quite understand (and am not sure I want to). But the upshot is, humans are ecosystems.

But does this mean, as the Reuters headline claims, that we are not entirely human? Well, it depends what you mean by "we" and what you mean by "human" (how's that for an if-by-whiskey argument?). Are our bodies entirely human? Well, DNA found within the boundaries of the human body isn't necessarily human DNA, and never has been. But DNA in human germ cells is, no matter how many bacteria live in our guts. So, does "completely human" mean "containing, at any given moment, only human DNA," or does it mean "having only human DNA govern your initial genetic development"?

Certainly the presence or absence of intestinal flora has a huge effect on an organism, potentially an effect that could alter later gene expression. But I'm not sure this makes us "not completely human." The Earth is inhabited by all sorts of flora and fauna, all of which have profound effects on it (none more than us). None of these are planets. Is the Earth not a planet either?

If the question you're asking is whether our minds are completely human, the answer at first seems simpler. Gut flora probably don't have an enormous effect on our proprioception, emotions, consciousness -- the things that make us us. Again, the presence or absence of these bacteria may cause environmental effects profound enough to affect cognitive development or even gene expression in the brain, but I don't see any evidence that they can make us psychologically or neurologically nonhuman. And yet once again, one has to consider the fact that in a sense, we've never been purely human on the cognitive level either. In our highly technological age, we're becoming more aware of the "cyborg consciousness" that occurs when human brains rewire themselves to accommodate iPods or laptops or cell phones. There's nothing natural about using a computer or an MP3 player, but these technologies become transparent as we train our brains to think of them as extensions of ourselves. It's even more obvious with cars, where we actually use our proprioceptive sense to avoid obstacles or parallel park -- we treat this unwieldy metal casing as a part of our own bodies. This is what it means to be "posthuman" -- a fundamental interrelation between technology and embodiment.

Freaky 21st century stuff, right? But we've been absorbing technology like this since we, as a species, were in short pants. Consider eyeglasses. Bicycles. Crutches. Musical instruments. Weapons. Flint arrowheads. Rocks and sticks. The very earliest cultural and societal advances, the ones we think about as setting us apart from less civilized animals, involved using tools as improved fingernails or teeth, longer arms or digits, stronger fists. Since we've been human, our adaptable plastic brains have allowed us to incorporate technology into our self-perception. Without this ability to have our tools rewire our brains, we wouldn't have the dexterity and control that would allow us to throw a spear or manipulate a paintbrush. Thus, in what might look like a paradox, we've been posthuman as long as we've been human.

In other words, part of what it means to have a human mind is to have a mind that incorporates and adjusts to peripherals. Part of what it means to have a human body is to have a body that works symbiotically with other organisms like bacteria. Does this multiplicity make us "not completely human"? Quite the opposite.

10 Comments:

Laura said...

Tangentially: there have been many, many times when I've accidentally bumped my friend's wheelchair and been surprised that she didn't say "ouch." In other words, my perception of her body incorporated the non-human wheelchair.

Also, I'm clumsy.

I experience a version of this all the time, since I have worn glasses since I was about eight. They are part of my self, if not my body, and I feel profoundly strange for a few days when I get a new pair. A smaller example is that I often feel "naked" if I forget to put on earrings or a necklace.

As humans, we incorporate things that are not "natural" or endemic to humans into our bodies and our lives every day, like glasses, digestive bacteria, and hot man-on-man action. People getting up in arms about what's natural for humans are missing the point of being human.

6/04/2006 4:42 PM  
jess said...

Right... "natural for humans" doesn't mean a hell of a lot. Are shoes natural for humans? Codex books? Silverware? Just because a technology is transparent doesn't mean that its use is innate. And our species is sufficiently advanced that to ignore millions of years of civilization and say "well, pretend humans were in a state of nature" is to engage in a really nonsensical counterfactual.

As for feeling naked if you don't put on earrings or a necklace... you also feel naked if you don't put on clothes, and yet clothes aren't exactly provided for in the human genome.

Between the two of us we've had close friends or relatives with wheelchairs, false limbs, glass eyes, pacemakers, glasses, contacts, dentures, and artificial heads made entirely of packing foam (you). And none of them, except you, have been anything other than human.

6/04/2006 8:49 PM  
Rev. Tom said...

This is an utterly fascinating line of thought. I've often thought that should I ever find myself in the unfortunate situation of losing a limb, I would do some entirely goofy and awesome things with my artificial limbs -- things like concealing a liquor flask in an artifical leg, for example.

But, as a geographer-type, I feel the need to inject even more thought fodder into this discussion. Along the lines of thinking of ourselves as ecosytems for things like bacteria, we can go in the other direction and look at our specific adaptations to urban life as well as the diminished abilities stemming from our removal from the wild, "natural" world. William Kronon, in the opening pages to his supremely excellent book Nature's Metropolis, goes into a lengthy cogitation about the natural word, the built environment, and the resultant changes and hybridization that occur as things become "second nature" to us.

As for myself, I'm just waiting for dental insurance so that I can get those titanium teeth which I hope will receive radio waves... wireless-fidelity... in my mouth!

6/05/2006 12:36 AM  
jess said...

One of my favorite general scientific concepts is emergence -- watch as I force my students to think about bottom-up knowledge production! -- which makes possible some very interesting analogies between internal and urban ecosystems. I've been planning a blog post on emergence for a while, but I keep getting sidetracked by things like baby tigers and chocolate cars.

I think you should probably get a chainsaw arm. Actually, though, I love the low-tech appeal of a flask-leg. The idea of posthumanism and transhumanism so often gets associated solely with Kurzweil-style "singularity," or worse, sp00ky speculations by cyberpunk wannabes. It's important to remember that we're built to use technology, and that a lot of things are technology -- like flasks, and books, and non-cybernetic artificial limbs. If I'd thought about it, I would have mentioned the phenomenon of people's phantom limbs "inhabiting" a prosthetic -- they almost consciously project their proprioception into the peripheral. We hardly need mirror-shade implants and Wolverine claws to be posthuman.

6/05/2006 9:06 AM  
JP said...

Again, the presence or absence of these bacteria may cause environmental effects profound enough to affect cognitive development or even gene expression in the brain,

check out agnostic's series on "genius germs" for a theory on well, that.

nice post, BTW

6/05/2006 10:15 AM  
Lynne said...

Well, when we see other living things living in symbiosis, we still categorize them separately - corals and colorful microbes, rhinos and those birds that hang out on them, etc. even (or maybe particularly) if it's parasitic and not symbiotic, we still think of it separately (I don't think that people with tapeworms think of the tapeworms as extensions of themselves, though the worms do change their biological processes). I am perhaps one of the most gut-flora conscious people you're ever going to meet, and I'm very concerned about them and the balance between their communities and our relative healths. But I don't think of them as part of me. I wonder why I don't. There must be a separation between how we *think* about ourselves and what our brains are actually doing while we aren't paying attention. Our brains do have amazing abilities to use inputs we didn't grow ourselves, as though we had actually grown them.

6/05/2006 10:37 AM  
Lynne said...

This Slate article from the weekend is pretty condescending, but it relates to your post and makes some interesting points, from a different angle:

http://www.slate.com/id/2142987/

6/05/2006 1:14 PM  
jess said...

JP, thanks for the link... very cool. That'll teach me to underestimate the power of germs. The more I think about it, the more absolutely absurd it is to pretend there's such a thing as being "human" without having trillions of nonhuman inhabitants.

About the Slate article... man, Saletan gets to have all the fun. I agree that it's snarkier than it needs to be -- that's his MO (MODUS OPERANDI!!!), but still, it sometimes comes off as dismissive. On the other hand, I'm kind of dismissive of some of the transhumanists, myself. I mean, the Dr. Moreau guy? He can't be serious, can he? And that other guy -- his name's never "Aubrey de Grey"! Saletan doesn't have to make the (false, and therefore purely rhetorical) claim that D&D geeks grow up to be transhumanists, but on the other hand transhumanists are pretty weird.

Saletan's questions, which he introduces at the beginning of the piece, are to me much more interesting than any of the panels he describes. What is the threshold of "weird"? Certainly there are cultural differences, but I think he's right that there are physical alterations that we see as perfectly normal, others that are downright bizarre. It's easy to see that, say, giving yourself the body of a cat would be much weirder than a circumcision. What's harder is to figure out where we draw the line. I don't think there's anything weird about gender reassignment surgery, which is a wholly transformative procedure just like getting a cat body. I do think there's something weird about elective limb removal, which isn't. So what's the cutoff? (I'm inclined to say it's just familiarity, but it would still be interesting to discuss.)

6/05/2006 5:57 PM  
Anna said...

I think it's also worth pointing out that gut flora aren't actually inside us except by our own perception. If you think topologically, the digestive tract is a big hollow cylinder running down our middles and people are homeomorphic to circles, not totally solid. So the gut flora are in that sense not in us but on us, the way face mites live on our skin. Not that it really changes anyone's argument about symbiosis.

6/10/2006 6:41 PM  
jess said...

Oh my, I hadn't thought about that... human as Klein bottle!

6/10/2006 11:36 PM  

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