The Parasite Files

At the Loom we believe that the path to wisdom runs through the Land of Gross. We do not show you pictures of worms crawling out of frog noses merely to ruin your lunch. We do not urge you to check out these freaky videos of worms crawling out of frog mouths and fish gills merely to give you something to talk about at the high school cafeteria table tomorrow (Dude, you totally will not believe what I saw...) These images have something profound to say. The worm in question is the gordian worm or horsehair worm, Paragordius tricuspidatus. It has become famous in recent months for its powers of…
Even I have my limits.
Loyal readers need no introduction to this bit of entomological "Faces of Death." Others who think this must be some sort of hoax, read this (or this). Courtesy of Dr. Fred Liebersat, oracle of the emerald cockroach wasp.
The Discovery Channel picked up my cockroach zombie story and interviewed Dr. Fred Liebersat on his research. They included some cool footage of the roach and its sinister wasp brain surgeon. To watch, go to their archives and scroll to "Roach-o-rama." Unfortunately, there's no footage of young wasps poking their heads out of their cockroach hosts, but perhaps that was too hard to catch. Or maybe just too disturbing...
My post on zombie roaches and brain surgeon wasps seems to have hit a nerve. There have been well over 100,000 hits on that post alone, and 175 comments have been posted. I imagine that most people haven't read through all 175 (many of which have more to do with God than wasps). But I would urge any interested readers to check outthis one from Gal Haspel, who spent seven years in grad school contemplating the sinister glory of Ampulex compressa. Update 2/15: Gal is now fielding questions in the comment thread, discussing new research on matters such as how the wasp knows where in the brain to…
I collect tales of parasites the way some people collect Star Trek plates. And having filled an entire book with them, I thought I had pretty much collected the whole set. But until now I had somehow missed the gruesome glory that is a wasp named Ampulex compressa. As an adult, Ampulex compressa seems like your normal wasp, buzzing about and mating. But things get weird when it's time for a female to lay an egg. She finds a cockroach to make her egg's host, and proceeds to deliver two precise stings. The first she delivers to the roach's mid-section, causing its front legs buckle. The brief…
Are brain parasites altering the personalities of three billion people? The question emerged a few years ago, and it shows no signs of going away. I first encountered this idea while working on my book Parasite Rex. I was investigating the remarkable ability parasites have to manipulate the behavior of their hosts. The lancet fluke Dicrocoelium dendriticum, for example, forces its ant host to clamp itself to the tip of grass blades, where a grazing mammal might eat it. It's in the fluke's interest to get eaten, because only by getting into the gut of a sheep or some other grazer can it…
This year's Nobel Prize in medicine or physiology was announced this morning. Barry Marshall and J. Robin Warren won for discovering that ulcers can be caused not by stress or genes but by a bacterium called Helicobacter pylori (shown here). As my fellow Corantean, Derek Lowe, observes, this story follows the classic arc from, "You're completely bonkers" to "You're going to Stockholm." But it also illustrates a point that I made when last year's Nobelists were announced: it demonstrates how intimately woven evolutionary biology is becoming with medicine. It turns out that Helicobacter…
I've got two stories in tomorrow's New York Times about getting sick. One is about malaria. I've always been fascinated by how parasites can manipulate their hosts for their own ends, and much of my book Parasite Rex is dedicated to explaining how this creepy remote control works. I've come across many new examples from time to time. Now a new study shows that the parasite that causes malaria can alter us humans to turn us into good mosquito bait. As with most stories about life, this one is ultimately about evolutionin this case, how parasites repeatedly have evolved ways to boost their own…
One of the most exciting lines of research in evolution today is how parasites have become so good at making us sick. A case in point appears in the latest issue of Genome Biology (full text of paper here). It appears that parasites have stolen one of our best lines of defense and now use it against us. When bacteria or other pathogens try to invade our bodies, we marshall an awesome system of biochemistry to ward them off. Recently, a group of French and German molecular biologists took a look at a key piece of that system, a molecule studding the surface of our cells called alpha-2-…
Few humans have been as successful in Hollywood as parasitoids. Parasitoids are a particularly gruesome kind of parasite that invariably kills its host by the time it becomes an adult and is ready to leave the host's body. A parasitoid female wasp, to give one example, will fly along until it finds a caterpillar of some particular species. It lands on top of the caterpillar, jabs an egg-laying stinger into the caterpillar's body, and injects some eggs. The eggs hatch, the wasp larvae feed on the living caterpillar from within, and then, when they're ready to metamorphose into adults, they…
Biologists these days can paint many different portraits of the same organism. They can follow the tried and true style of Aristotle and paint with a broad brush, describing what they can see with the naked eye--number of legs, color of hair, live young or eggs. Or they can paint a creature at the cellular level--the twist and turns of collagen fibers in a horse hoof or the poison-producing organelles of a rattlesnake. In the past few years a new kind of portrait has been hung in the biological museum: a portrait of the genome. In the thousands or millions of DNA base pairs, genomes can…
As someone who writes a lot about evolutionary biology, I've often had people say to me, "I just can't believe that evolved." Originally, that referred to the lovely side of nature--the beauty of flowers, for example, or the grace of birds in flight. The implication was that these things were so beautiful and intricate that they had to be created for a purpose--a beautiful purpose, obviously. But after I started writing about parasites, that underwent a fascinating change. Parasites may be deadly and gross, but they also have some mind-boggling adaptations. Most mind-boggling of all is the…