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Wasp creates zombies out of roaches via brain surgery
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| Tranc3 |
ing creepy, almost as creepy as gravity or electromagnetism, or even quantum.
http://loom.corante.com/archives/20...f_parasites.php
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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 paralysis caused by the first sting gives the wasp the luxury of time to deliver a more precise sting to the head.
The wasp slips her stinger through the roach's exoskeleton and directly into its brain. She apparently use ssensors along the sides of the stinger to guide it through the brain, a bit like a surgeon snaking his way to an appendix with a laparoscope. She continues to probe the roach's brain until she reaches one particular spot that appears to control the escape reflex. She injects a second venom that influences these neurons in such a way that the escape reflex disappears.
From the outside, the effect is surreal. The wasp does not paralyze the cockroach. In fact, the roach is able to lift up its front legs again and walk. But now it cannot move of its own accord. The wasp takes hold of one of the roach's antennae and leads it--in the words of Israeli scientists who study Ampulex--like a dog on a leash.
The zombie roach crawls where its master leads, which turns out to be the wasp's burrow. The roach creeps obediently into the burrow and sits there quietly, while the wasp plugs up the burrow with pebbles. Now the wasp turns to the roach once more and lays an egg on its underside. The roach does not resist. The egg hatches, and the larva chews a hole in the side of the roach. In it goes.
The larva grows inside the roach, devouring the organs of its host, for about eight days. It is then ready to weave itself a cocoon--which it makes within the roach as well. After four more weeks, the wasp grows to an adult. It breaks out of its cocoon, and out of the roach as well. Seeing a full-grown wasp crawl out of a roach suddenly makes those Alien movies look pretty derivative.
I find this wasp fascinating for a lot of reasons. For one thing, it represents an evolutionary transition. Over and over again, free-living organisms have become parasites, adapting to hosts with exquisite precision. If you consider a full-blown parasite, it can be hard to conceive of how it could have evolved from anything else. Ampulex offers some clues, because it exists in between the free-living and parasitic worlds.
Amuplex is not technically a parasite, but something known as an exoparasitoid. In other words, a free-living adult lays an egg outside a host, and then the larva crawls into the host. One could easily imagine the ancestors of Ampulex as wasps that laid their eggs near dead insects--as some species do today. These corpse-feeding ancestors then evolved into wasps that attacked living hosts. Likewise, it's not hard to envision an Ampulex-like wasp evolving into full-blown parasitoids that inject their eggs directly into their hosts, as many species do today.
And then there's the sting. Ampulex does not want to kill cockroaches. It doesn't even want to paralyze them the way spiders and snakes do, since it is too small to drag a big paralyzed roach into its burrow. So instead it just delicately retools the roach's neural network to take away its motivation. Its venom does more than make roaches zombies. It also alters their metabolism, so that their intake of oxygen drops by a third. The Israeli researchers found that they could also drop oxygen consumption in cockroaches by injecting paralyzing drugs or by removing the neurons that the wasps disable with their sting. But they can manage only a crude imitation; the manipulated cockroaches quickly dehydrated and were dead within six days. The wasp venom somehow puts the roaches into suspended animation while keeping them in good health, even as a wasp larva is devouring it from the inside
Scientists don't yet understand how Ampulex manages either of these feats. Part of the reason for their ignorance is the fact that scientists have much left to learn about nervous systems and metabolism. But millions of years of natural selection has allowed Ampulex to reverse engineer its host. We would do well to follow its lead, and gain the wisdom of parasites. |
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| sakabatou |
Sweet!
All that evolution rubbish at the end though.... an animal is suddenly going to evolve to instinctly sting a cockroaches head,with sensors so precise it can tell where it is in the roaches brain,THEN send a sting that neutralises that part of brain?
What would you say the chances of that happeneing are? |
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| LiGHT78 |
| Cool yet a tad disturbing. |
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| Moongoose |
| quote: | Originally posted by sakabatou
What would you say the chances of that happeneing are? |
Over a wery long period of time. Preety good i would say. |
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| sakabatou |
| quote: | Originally posted by Moongoose
Over a wery long period of time. Preety good i would say. |
Explain. |
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| venomX |
| quote: | Originally posted by sakabatou
Explain. |
im dont know that much about stats, but given the thousands of thousands of years theyre's been for many different types of wasps in this case to evolve and either succesfully reproduce or die off, theyre's probably been quite a many, |
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| DJ Robben |
| that was a fantastic read, a lil creepy in the sense. but interesting. |
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| aliyans |
| quote: | Originally posted by sakabatou
Sweet!
All that evolution rubbish at the end though.... an animal is suddenly going to evolve to instinctly sting a cockroaches head,with sensors so precise it can tell where it is in the roaches brain,THEN send a sting that neutralises that part of brain?
What would you say the chances of that happeneing are? |
well.. it did happen. this type of evolution doesn't suddenly just occur in a day or two.. it takes hundreds of thousands of years.. gradually.. one(several?) mutation at a time.. |
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| occrider |
| quote: | Originally posted by sakabatou
Sweet!
All that evolution rubbish at the end though.... an animal is suddenly going to evolve to instinctly sting a cockroaches head,with sensors so precise it can tell where it is in the roaches brain,THEN send a sting that neutralises that part of brain?
What would you say the chances of that happeneing are? |
Pretty good. This is analgous to the eye. It didn't start off as an eye it started off as a light receptor ... then it evolved into something that could vaguely distinguish shapes ... then it involved into something that could distinguish spatial orientation ... etc,etc.
Just because something is complex doesn't mean it's irreducably complex. |
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| whiskers |
| quote: | Originally posted by occrider
Pretty good. This is analgous to the eye. It didn't start off as an eye it started off as a light receptor ... then it evolved into something that could vaguely distinguish shapes ... then it involved into something that could distinguish spatial orientation ... etc,etc.
Just because something is complex doesn't mean it's irreducably complex. |
in fact, scientists claim the eye evolved independently up to 40 times.
evolution is very simple to understand - a creature has a trait A that helps it live longer and reproduce more (i.e., an eye to spot predators, or venom that zombifies its prey)
the trait is passed on to the offspring and the offspring in which the trait has mutated more favorably are suited best for survival and again pass on their genes. small steps over thousands of years. |
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| astroboy |
| quote: | Originally posted by sakabatou
Sweet!
All that evolution rubbish at the end though.... an animal is suddenly going to evolve to instinctly sting a cockroaches head,with sensors so precise it can tell where it is in the roaches brain,THEN send a sting that neutralises that part of brain?
What would you say the chances of that happeneing are? |
Higher than the chances of an omnipotent, omniscient ever present old man in the sky engineering the whole thing. |
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