September 27, 2005
Parasitic Worms Prompt Grasshoppers To Leap To Their Deaths
Okay, so this story caught my interest because the National Geographic article said that that parasitic worms were "brainwashing" the grasshoppers into jumping into people's pools, causing them to commit suicide.
This is a great example of how writing and word usage in an article can greatly effect the slant. Brainwashing? This word implies intent, intelligent design (heh,heh), not to mention it has "evil" connotations.
Scientists say hairworms, which live inside grasshoppers, pump the insects with a cocktail of chemicals that makes them commit suicide by leaping into water. The parasites then swim away from their drowning hosts to continue their life cycle.
This biochemical tampering appears to drive the grasshopper to water just when the hairworm is ready to reproduce.
What if I were to say that a type of parasitic worm makes you hungry, causing you to eat a lot. Would that be brainwashing? Or would it simply be a biological response to not getting enough energy from food consumption because the parasite is stealing some of it?
Now let's say that the parasite makes you thirsty - or makes you feel like you've been set on fire. You jump into a pool - either to drink or to cool off. Were you brainwashed or just incredibly uncomfortable and acting on it?
According to Answers.com, brainwashing is to teach something to accept a system of thought uncritically. I don't think brainwashing applies here for several reasons. First, you'd have to believe that grasshoppers have critical thinking abilities. Secondly, what are the chances that a parasitic worm used mental coercion to compell the grasshopper to act?
I think it's more likely that the side effects of the parasitic worm - the chemicals it produces make the grasshopper feel something that would cause it to jump into water (thirst, heat, ask a grasshopper expert). The side effect could be a mutation that has continued to be passed from worm generation to generation because these are the worms that successfully make it into the next stage of their life. It's just survival of the fittest, or at least the cleverest.
Parasitology is a type of symbiosis (living together). There are three general kinds of symbiotic relationship: phoresis (travel together, no real benefits), commensalism (it benefits, host is neither helped nor harmed), mutualism (both benefit), and parasitism (lives at the expense of the host).
I guess I was just tweaked by the wording of the article, but I have to admit, it's an interesting, if creepy, example of adaptation.
So, in a little side note... my husband Shane and I try to read each other's blog posts whenever we can, but it often takes too much out of our days, so we instead we talk about how we haven't kept up with posts over dinner or on walks and discuss some of the more interesting topics. Sometimes this can be really funny, like when we're talking about brainwashing parasitic worms while serving ourselves yummy asian lettuce wraps at the local salar bar Fresh Choice (a personal dining favorite).
Posted by sorsha at September 27, 2005 2:02 PM
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