A Romance to make Seth Brundle Weep

Haven’t been posting the past few days.  I really should have written something to commemorate Darwin’s 200th birthday, but how can you celebrate when the latest Gallup poll shows that over 60% of the US population is too blinkered, too misled, or too downright stupid to grasp the reality of natural selection? And I would have posted something on the latest ep of BSG, if it hadn’t turned out to be the lamest episode of the season, an extended talking-heads infodump broken only by —  wait for it — another talking-heads infodump, both of which sketched the outlines of what I fear may be the clumsiest backstory retcon since X-Files limped across the finish line.

But today is Valentine’s Day, that most romantic of occasions when Hallmark, de Beers, and Laura Secord try extra hard to convince us that (fucking + pheromones) = (everlasting commitment + gratuitous spending),  and hope that no one notices how the “hearts”  festooning  valentines  don’t look like hearts at all, but rather the inverted asses of receptive females.  So it is only fitting that this was the week during which Science unveiled a bond that is the very archetype of intimacy and lifelong commitment (overview here; research paper here).  Any doof with a dick will tell you that he can’t live without you.  Here’s someone who means it:

Parasitoid wasp

You’re looking at one of those parasitic wasps that lay their eggs in live hosts.  Said host, as you can imagine, isn’t especially keen on being devoured alive from the inside out, and has a whole vigiliant immune system ready to fight off any foreign invaders of the flesh. The wasp counters by injecting, along with her eggs, an aliquote of a virion (basically, a virus without the crunchy coating) that short-circuits the immune response of the victim.

So far, so good.  These basics aren’t news to anyone who caught the Alien flicks.  But here’s where it gets interesting: the virus can’t replicate outside the wasp.  It literally1 leaves its balls behind — or more precisely, the code that handles replication and the synthesis of the protein sheath stay behind, embedded in the wasp’s own genotype.

At first glance this might seem unremarkable:  after all, that’s how all viruses work, right?  They insert their code into the control program, hijacking production and getting the cell’s assembly line to start pumping out more virii instead of the usual products.  But there’s the rub:  usually, it’s complete copies of itself that the virus generates, not these half-assed squiggles of DNA that don’t even come with packaging, don’t even come with code for packaging.  These virions leave the wasp, and they’re toast.  They don’t have enough parts left to even penetrate another host cell, much less take over its replicative machinery.  All they can do is cover the eggs of parasitic wasps and keep the host’s immune system from raising the alarm.   It’s the wasp‘s genome that builds them now, using embedded viral genes that never leave the cell.  Without the wasp, these viruses can’t replicate.  And without the virions protecting their eggs, neither can the wasps.

I don’t think we’re even talking about two species any more.  I think these two organisms have become so inextricably fused that we’re talking about a single species, born of the fusion of two.  What was once a virus is now a glorified glandular secretion, part of a greater whole.  Could any relationship be more intimate?

Back when I was a real biologist I attended a guest lecture by one Lyn Margulis, the first person to figure out that the mitochondria in our cells were once free-living organisms in their own right.  She was pimping the next iteration of that theory, the radical proposition that species could fuse together as well as split apart.  I remember being unimpressed by the examples she cited; all those worms with symbiotic microbes inside them still gave birth to pristine offspring, after all, each of which had to be inoculated afresh.  It seemed to me that you couldn’t say that two species had fused if they had to split up again and then rediscover each other with each new generation, and when I raised my hand Prof. Margulis didn’t have an answer.

But I think these little braconid wasps may have finally handed her one.

1Well, metaphorically-literally. Phages have no actual balls, of course.



This entry was posted on Saturday, February 14th, 2009 at 2:35 pm and is filed under biology, evolution, science. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
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Leona
Guest
13 years ago

Reminds me of the tree people in the ‘Enders Game’ saga by scott card. The ‘pequeninos’ or whatever they were called. Fused with alien biology. Turned into trees and had to get ‘planted’ to move into the next phase of their weirdo life cycle. Gah… I can’t remember which book it was.

As for BSG I have completely lost the plot. I dunno what’s going on anymore… I guess I have to re-watch online or something and find my place again.

shrike75
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shrike75
13 years ago

It was the second book of Ender, “Speaker for the Dead”

Seth
Guest
13 years ago

I suppose it was inevitable that a mention of nauseating retcons would lead to a comment about Speaker for the Dead (hack, cough)

Seriously when I read this post my mind crinkled kinked like a jiffy pop on the stove hitting its thermal stride. The sheer awesomeness of nature never seems to disappoint.

Good timing too I had just hit a lull in thinking my 101 understanding of life was getting good. I can’t wait to hear some creationist exclaim something like this:

“Gawd had duh put duh DNA in da wasp or it wouldn’t have no chance a’ evoluting.”

Man that’s a creative parenting strategy.

Nick
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Nick
13 years ago

Hrm, I think I read something about this sort of thing, but in a mite, or a chewing lice, or one of those loser arthropods no one likes. I can’t–for the life of me–find the organism that they discovered it in.

But anyway, that’s crazy. I love biology because you find out these things that you would’ve never thought of, but in retrospect, you wonder why you didn’t think of them yourself–as they end up making perfect sense. I remember when my virology professor mentioned that the “junk DNA” could be/is just three billion years of inactivated toxic data delivered to us by evolving proteins, to give us the sniffles or death by massive hemorrhage.

I can’t help but think of this as sort of a viral retirement. Think of it like Florida. When you’re no longer young and deadly, you just retire to a genome and let the endogenous polymerase take over your job. All in all, it’s sort of a stupendous joke. Viruses do awful things to us, grotesqueness that even the most devious mind couldn’t conceive of. But they have only a passing interest in such things, until they can figure out how to hang out.

john
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john
13 years ago

Interestingly, nearly the same percentage that voted for that charlatan obama. I would not be surprised to find that many of those fooled by the creationists’ arguments were also fooled by the socialist in american clothing.

Denni
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Denni
13 years ago

I’m chuffed to see that the viral origin of polydnaviruses has been confirmed.

The idea that species can fuse is gaining ground. There was an article in a recent New Scientist (‘Uprooting Darwin’s Tree’, 24th January–with the risible cover headline ‘Darwin was wrong’–meh!) where species fusion is discussed. A stunning example is the starfish Luidia sarsi. But more importantly, retroviral remnants may be needed to prevent immune rejection of a pregnant woman’s fetus:

http://www.thefreelibrary.com/Viral+legacy+may+make+pregnancy+possible-a017408431

Seth
Guest
13 years ago

John said: “Interestingly, nearly the same percentage that voted for that charlatan obama. I would not be surprised to find that many of those fooled by the creationists’ arguments were also fooled by the socialist in american clothing.”

No intelligent american could have voted for John McCain. That’s as simple as it is. Obama won the nomination. It was that or a lousy old dotard and filthy biznatch wielding a big flaming abstinence only brand.

Oh and as someone from North Carolina I guarantee the only people voting for McCain were religious wingnuts, racist bastards and rich cunts.

Lesser of two evils. Obama could sodomize a baby with a giant rusty swastika and all I could say would be this: He’s still better than bush.

Cal
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Cal
13 years ago

As a youth I was told by well-meaning non-biologists that gut flora outnumber the cells in our bodies, and that the bacteria in our guts are necessary for proper digestion (maybe they meant metabolic function and vitamin synthesis) AND that the presence of these bacteria outcompete more virulent forms of invaders, and if that wasn’t enough, the presence of gut flora spurs the immune system by some mysterious agency, the majority of immune cells being in our intestines.

So, if our colonization by bacteria is so beneficial, doesn’t that practically make us symbiotes? I mean, I know, not literally, but aren’t we (almost) as dependent on Bacillus subtillus as the wasp is on the virions? I say yea, and so although the wasp’s dependency happens on a smaller, more basic level, parallels can be drawn almost everywhere, surely?

What if it turned out that, as a result of our dependency on bum-bugs we were dependent on other forms of life, as well? What if we weren’t actually able to survive for more than couple of generations on a sterile spaceship, because those unconscious passengers depended on something else that we didn’t bring with us?!

Damn you Circle of Life! Pardon me.

CP
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CP
13 years ago

Speaking of Margulis, have you seen the following article?

PMID: 18045538 (pubmed.org; type into search)

This describes a process that the authors call “entosis” in which a cell is able to invade another cell and essentially cannabilize it. The reason I thought to mention this is that it really provides a proof-of-principle example of endosymbiosis…or at least a great facsimile of it.