Things great and small

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As you likely know, Resonance Women’s Chorus, home to my major volunteer gig these days, just finished up the season with its marvelous concert on climate change. After being immersed in this earth-ish topic for months, it’s been fun to find myself stretched through other layers of reality by a handful of articles I've encountered—outward to this incomprehensibly vast cosmos of ours and inward to microscopic realms that touch on our very identity. Not trivial matters, but definitely fun.

(Before I get all wonky, check out these gorgeous roses I spotted on a walk the other day. If nothing else, they're testimony to two happy facts: it's spring and I'm out walking again. Hooray!)

So, as a hint of this perspective stretching I mentioned, I offer these few tidbits for your consideration. 

First, the microscopic: 

The first set of articles I read had to do with the relatively recent development of a new technique in the field of genetics. Not long ago, two geneticists developed a technique called CRISPR-Cas9, which gives scientists the ability to remove and add genetic material at will, altering an organism's genome—sperm, eggs, embryos—in a way that will be passed on to future generations. Here’s a video explaining it, if you're curious. The technique has already been used in rats, monkeys, and a few other species. Folks are pretty certain that it would work in humans. Genetic manipulation that is limited to non-germ cells (e.g., in GMO foods, gene therapy) already raises some ethical concerns. But this is about changes that will be transmitted to subsequent generations. Still unknown are how precise such changes can be (might I clip too much, insert too little?), how specific (what if I alter surrounding genes in the process?), and what the side effects might be (will eliminating, say, a gene that predisposes allergies also damage part of the natural immune response?).  

Aside from these technical issues, CRISPR raises huge ethical concerns—even theological ones. It could have great benefits in curing diseases, preventing birth defects, and so on. But it could also be used in questionable ways, like to engineer offspring sex, physical characteristics, intelligence, etc. Recently, a number of people working in the field called for a moratorium on this research in humans until these issues can be addressed. In the words of one scientist, “It raises the most fundamental of issues about how we are going to view our humanity in the future and whether we are going to take the dramatic step of modifying our own germline and in a sense take control of our genetic destiny.” Another comments, “I personally think we are just not smart enough—and won’t be for a very long time—to feel comfortable about the consequences of changing heredity, even in a single individual.”

Yet, just the other day I saw an article about scientists who had attempted to perform this research in human embryos. The experiment failed in most cases—the embryos died or the DNA was not altered as planned. In other cases, the results were as feared: in some, the DNA interrupted the process, resulting in some changed and some unchanged DNA. In other cases, non-target segments of the DNA were altered, a phenomenon some have called “collateral damage.” So the experiment basically confirmed that the scientists who had issued the warning were right. Still, this research also highlighted the possibility—even the high likelihood—that others will try again.

The questions this raises are just mind-boggling. What is identity? What does “I” mean if my DNA, the “building block” of my distinctive genetic makeup can be altered? And what does it mean to be a human being if the core features of human existence might be subject to alteration? If these techniques get perfected, who decides what traits are worthy of continuing and which are not? It is impossible not to hear the echo of early 20th century programs of eugenics in these questions.

But in a different microscopic domain, another story seems to bring good news: I wrote here before about scientists’ conclusion that viruses make up over 8% of our DNA. These viruses are evolutionary hitchhikers, organisms that infected our long-ago ancestors and that gradually became incorporated into our very genes. Now, that’s mind stretching enough by itself—nearly 1/10 of our DNA consists of viruses! But even more astounding is what these viruses do for us. In that earlier post, I noted that they may be responsible for the evolution of the placenta (the placenta! We’re talking here about the very beginning of our individual selves). And now, last week, I also learned that some such viruses—endogenous retroviruses—may “come alive” during the earliest stages of embryonic development. Retroviruses are not usually our friends—think HIV—but in this case, these endogenous retroviruses may actually serve to immunize the embryo against other viruses. 

Now, this is good news, but it still challenges any simplistic notions we might hold about ourselves as individual, self-contained, unitary beings. Just think about it … microscopic viruses—viruses!—stow-aways from pre-human history may be responsible for the placenta that supported our individual prenatal life and for our immunity to viruses that might otherwise have done us in. So don't you wonder wonder, where does the “I” in this process end and the “they” begin?

To leap from the microscopic to the telescopic ...

Two other recent stories escorted me back into my recurrent fascination with the cosmic. This past week was the 25^th anniversary of the launch of the Hubble telescope, which, as you likely know, has rewritten our understanding of the universe—and illustrated the book. The Internet was full of Hubble photo gems this week. In case you missed them, I’ll paste in a few, and you can click here for more and here for even more.  

                                                                                  

Hubble had some struggles from its earliest days (I’m tempted to say it was star crossed, but that seems too easy), with a microscopic flaw in the mirror that caused blurry views of even nearby objects. But with some clever fixes over the years by astronauts turned telescope experts, Hubble has taught us more about the cosmos than we ever knew there was to learn. As you may know from previous posts, I’m a totally amateur but enthusiastic observer of things astrophysical, so I’ve been paying attention to Hubble’s discoveries for years. This anniversary provided a delightful visual memoir of Hubble’s life so far, and I’m hoping for more.

And then, just today, I came across a short story about another recent Hubble-fueled finding: out there in the universe, there are “runaway galaxies,” and with Hubble's help, we’re starting to understand them. Scientists have known for some time about runaway “rogue” planets, which have either been ejected from their orbits around stars or somehow never belonged to a star system. They’ve also suggested the existence of runaway galaxies that are moving so fast they sail free from the “local cluster” of galaxies whose gravity generally holds galaxies together in a group. And now Hubble has spotted a runaway galaxy and tracked its trajectory as it veers away from its orbit and heads off into … somewhere. I love that the universe is so unruly.

So, I find this stuff fascinating in its own right. But this week, with my thoughts shifting from the issue of climate change—which is global, but local, in the planetary sense—to matters larger and smaller, I realized that both directions of my drift these recent days—the microscopic and cosmic—raise very similar questions: Who are we? What counts as human if much of our substance is actually other organisms? Who do we become  if we alter the genome that defines who we "naturally" are? Where is our place in a universe whose early beginnings over 13 billion years ago is just now coming into sight and whose extent, some would argue, is infinite? And that remains stubbornly errant.

If I drift back from the vast, cosmic question to this smallish, ordinary planet, I wonder at our arrogance to think we matter at all. If I move the other way, to the microscopic, I wonder if we realize how tentative and ephemeral our existence is. Either way, I'm struck by the astonishing improbability of it all. Which cycles me back to earlier musings on this very question, shared here many blogs ago.

I float in these dilemmas for a while, and then go about my business as if none of these questions mattered, as if they hadn't come to mind. Until they do again.

I wonder what that means. 

© Janis Bohan, 2010-2015. Use of this content is welcome with attribution and a link to the post. 

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Bacteria, viruses, and life itself

We are a society of germophobes. We are preoccupied with cleanliness as a matter of health. We run to the doctor if a cold doesn’t disappear in a few days, eager to stamp out whatever germs are making us feel so awful. All of this makes sense from the perspective of avoiding or eliminating disease. But, as with most things, life is more complicated than this.

Here are two cool bits of information I've come across in recent days that might make us think twice about our germicidal tendencies.

The first is about a bacterium called Clostridium difficile, “C. diff” to friends. Health care professionals are worried these days about a C. diff “epidemic.” C. diff can cause symptoms ranging from diarrhea to life-threatening inflammation of the colon. And here’s the kicker: taking antibiotics, perhaps to fend off some other nasty bacterium, actually increases your risk of getting C. diff. This happens because antibiotics also kill off the useful gut bacteria that usually keep C. diff. in check. Mild illness caused by C. diff may actually get better if you stop taking whatever antibiotics you’re on. Severe C. diff symptoms require treatment … get this … with a different antibiotic. Unfortunately, drug-resistant strains of C. diff are cropping up as the bacterium adapts to our overuse of antibiotics. 

So here’s how it works: we take antibiotics to kill off bacteria, also killing off the wrong bacteria, making us more susceptible to C. diff (a bacterium), against which further antibiotics are increasingly feeble, perhaps increasing our vulnerability to C. diff.

Clearly, this is a medical challenge. But it’s also a philosophical, even an existential challenge. For one thing, it challenges our usual neat categories of “good” and “evil.” It forces us to reconsider the agents that we see as invaders and the drugs that we see as heroic defenders. It’s harder to keep the categories clear when inviting a defender increases our vulnerability to the invader, when the rescuer is a potential villain.

OK, hold that thought for a minute …

Then, just to make things more interesting, here’s another tidbit. To quote from an article in Discover magazine, “If not for a virus, none of us would ever be born.” Hmmm … a virus as the heroine? It seems that there is particular gene that’s essential for the placenta to do its job of transmitting nutrients and wastes between the mother and the fetus. And get this: this gene is not a human gene at all. Instead, it seems to be a gene from a virus.

 Apparently, over the millennia, our ancestors have collected souvenir fragments from the viruses that infected them (with those miserable diseases that we are so eager to snuff out). These virus fragments are like hitchhikers, slipping into our DNA and changing the direction of evolution. In fact, it turns out that fragments of viruses make up over 8% of our DNA. Who knew?! And imagine: we have such a virus to thank for the placenta, the amazing organ that makes human life possible.

So this is fascinating in itself. But it also brings me back to that puzzle: how do we know which visitors to fight off and which to welcome? And, on a larger plane, who do we think we are, anyway? We plan and maneuver and study and investigate and invent … and still, we’re products of the very things we resist, and we’re not really sure how to differentiate among the good, the bad, and the just plain ugly (but nonetheless good).  

I won’t expound on the obvious parallel here—what/who we resist and exclude in our own lives and how they might sustain us in the end, if we can only let them. We’ve all heard that lesson many times. But these ideas also bring me to a frequent (for me, at least) train of thought, one that arises more and more as I age:

We are just a blink in time. We are not, despite some politicians’ apparent belief to the contrary, the final outcome of evolution. We are some sort of step in a much larger process. Here we find ourselves: hugely dependent on the tiniest of agents, even as we fight them with all our scientific prowess. And down the line, even if we don’t wipe out the human species and destroy the planet through war, climate change, or distracted driving, everything will change. Slowly, but it will change. We’ll be gone, so it might seem irrelevant. But that’s what our long-ago ancestor might have thought, the one who got infected with the virus that made placentas possible. That is, if “thought” had evolved by then.

 This fascinates me, the long cascade of time. As I face the accelerating change in my own life—my body, my mind, my relationships, my general place in the world—I think a lot about change and mortality and the inevitability of both. The real value, to me, of this train of thought is the invitation to accept the flow and to recognize the uncertainty of our place in it. This is not to say that scientists shouldn't seek the cure for the common cold. It’s not to say that I should resign myself to a dispirited, passive decline in my aging years. It is only to say that time and change move on. I’m better at welcoming this some days than others. But bacteria and viruses are good reminders.