how is it I can be so antisocial when I have so much fun going out? party tonight...kickass. in a nutshell the most comfortable yet entertaining get together I've ever attended. conversation is like sex to me lately. maybe it's the lack of sex desensitizing my brain from any intimacy, even conversationally, that causes that feeling.
if you were wondering, yes I partook in the "festivities" this evening, and how.
pardon me while I geek out.
alcohol has my mind trippin this morning.
do you think ants conceptualize beyond a given physical distance their surroundings?
if you were wondering, yes I partook in the "festivities" this evening, and how.
pardon me while I geek out.
alcohol has my mind trippin this morning.
do you think ants conceptualize beyond a given physical distance their surroundings?
VIEW 4 of 4 COMMENTS
Our planet's rain forests - rich matrices of life which exist primarily in tropical regions - provide us with unique opportunity to observe life in all of its manifold and perplexing beauty. Most rain forests date back some two to three hundred million years. This extreme age has allowed many unusual and complex relationships to develop among the inhabitants of these tropical ecosystems.
In the rain forest of the Cameroon in West Central Africa lives a floor dwelling ant known as Megaloponera foetens, or more commonly, the stink ant. This large ant - one of the very few to produce a cry audible to the human ear - lives by foraging for food among the fallen leaves and undergrowth of the extraordinarily rich rain forest floor.
On occasion one of these ants, while looking for food is infected by inhaling a microscopic spore from a fungus of the genus Tomentella. After being inhaled, the spore seats in the ant's tiny brain and begins to grow, causing changes in the ant's patterns of behavior. The Ant appears troubled and confused; for the first time in its life the ant leaves the forest floor and begins to climb.
Driven on by the growth of the fungus, the ant embarks on a long and exhaustive climb. Completely spent and having reached a prescribed height, the ant impales the plant with its mandibles. Thus affixed, the ant waits to die. Ants that have met their ends in this fashion are quite common in some sections of the forest.
The fungus continues to consume first the nerve cells and finally all the soft tissue that remains of the ant. After approximately two weeks a spike appears from what had been the head of the ant. This spike is about an inch and a half in length and has a bright orange tip heavy with spores which rain down onto the rain forest floor for other unsuspecting ants to inhale.
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.
http://www.mjt.org/exhibits/stinkant.html
http://loom.corante.com/archives/2006/02/02/the_wisdom_of_parasites.php
[Edited on Apr 23, 2006 2:26PM]