Monday 26 Oct 09 / nature is one sexy mother
fair warning: this post might not be for the faint of heart, but i had to share it b/c it's completely ridiculous and fascinating. the other evening i was reading the september 09 national geographic in the bathroom (where i get most of my magazine reading done) and i started reading a saucy little article about orchids called 'love and lies'. that's right, 'love and lies.' if it sounds like the title of a harlequin romance mass market paperback, well, it read like one. to give you an idea of the angle the author took, the tagline under the title read:
"How do you spread your genes around when you're stuck in one place? By tricking animals, including us, into falling in love."
the article focused on the procreative habits of orchids. which sounds interesting enough i guess, though not necessarily novel. what little i'd heard of orchids in the past (primarily from the spike jonze movie 'adaptation') was all pretty interesting. and the article stayed at about that level of interestingness -- pretty -- until about 2/3 of the way thru it. and then it blew my mind.
[i'm quoting directly from national geographic from here on out, and it does get a bit graphic. but only in a national geographic kind of way. and not in the 'topless tribes of sub-saharan africa' national geographic kind of way. just in a 'replenish the earth' kind of way.]
If it's starting to sound as though I don't trust orchids, that's because I've seen what they can do to some of my fellow animals. There's a video on YouTube -- a riveting snippet of interspecies porn -- in which you can watch a wasp be utterly bamboozled, and then humiliated, by an Australian tongue orchid. The tongue orchid (Cryptostylis) lures its pollinator by deploying a scent closely resembling the pheromone of the female wasp (Lissopimpla excelsa). The male wasp alights on the tonguelike labellum, tail first, and commences to copulate with the flower, probing its interior with the tip of his abdomen until it bumps into the sticky pollinia, which attach themselves to the insect's posterior like a pair of yellow tails.
Having to play pin the tail on the pollinator is only the beginning of the wasp's humiliation. For with the tongue orchid we have passed beyond pseudocopulation into a realm even more perverse: More often than not, the wasp, in the throes of his misguided sexual exertions, actually ejaculates onto the flower.
Surely this represents the height of maladaptive behavior, and natural selection could be expected to deal harshly with a creature foolish enough to squander its genes having sex with a flower. ("Costly sperm wastage," is how the literature describes it.) That would be bad news for both the wasp and the orchid that depends on him. But as with so much else in the bizarre world of orchid sex, the matter is not quite so simple.It appears that in some insect species, such as Lissopimpla excelsa, females can reproduce with or without sperm from a male. With it, they produce the usual ratio of male and female offspring; without sperm, they produce only male offspring. How convenient—for the tongue orchid, that is. By inducing wasps to waste their sperm on its flowers, tongue orchids are decreasing the amount of sperm available to female wasps, thereby assuring themselves an even larger population of pollinators. Not only that, but the overabundance of male wasps increases competition for females, which makes the desperate wasps less picky in their choice of mates and that much more likely to fall for a flower.
What about the poor wasp? Why hasn't natural selection killed off an insect so dumb as to have sex with flowers? The best explanation I've heard is from John Alcock, who says that although the wasp may occasionally waste his genes on a plant, his "extreme sexual enthusiasm" is still a better reproductive strategy for an insect than being cautious about one's choice of mate. On balance, having sex with anything that moves yields more offspring, even if it also leads to occasional romantic disaster.
come on, seriously?! a stem fatale?! a femme petale?! a flower with a survival mechanism based on attraction, lust, deception, and ultimately the manipulation of the procreative habits of not just another floral species, but that of flying, flapping, brain-laden fauna? how ridiculous is that! so complex and mischievous. it's like the plot of some scary, sexy movie which, let's be honest, would probably star kate beckinsale. only it would be way better than any movie she's ever done (except serendipity, obviously). it would probably resurrect her career. anyways, this probably just makes me a complete nerd, which i'm okay with. speaking of, if anybody knows anybody who would want to pay me to make sexy nature documentaries, i'm available. and now if you'll excuse me, i'm gonna go re-read that last paragraph. i'm pretty sure there is a good metaphor for human single life in there somewhere. -d


