Cockroaches Make Group Decisions?

The Discovery Channel is reporting a recent study indicates that cockroaches govern themselves using simple group consultations before anything that affects the entire group. From the article: " The research determined that cockroach decision-making follows a predictable pattern that could explain group dynamics of other insects and animals, such as ants, spiders, fish and even cows. Cockroaches, Blattella Germanica, are silent creatures, save perhaps for the sound of them scurrying over a counter top. They therefore must communicate without vocalizing.

Comments

X-Files

[Dante Shamest]

Cockroaches are interesting enough to have been the focus of one X-Files episode, War of the Coprophages

In the X-Files episode "War of The Coprophages" cockroaches are seen to group together to murder people. The character Dr. Berenbaum (based on the University of Illinois entomologist) suggests that it is actually swarms of flying cockroaches that are responsible for most UFO sightings (they generate an electro-static field which can be illuminated dependent on atmospheric conditions). In one of the scenes, a cockroach that escaped can be seen crawling over the camera, making it appear that the viewer's television has become infested. Though the shot was not planned, the producers decided to leave it in the episode.

Roach Intelligence

[linguizic]

This is new to our understanding of roaches, but the article doesn't realy go in to what's amazing about this. Ants are pretty well understood, an ant colony is an aggregated indirect fitness machine. Since all the female offspring of the queen are related to eachother by 3/4 (why? because they're way cool!!), and the worker caste is sterile, they promote the fitness of their sisters who will become queens themselves and leave the colony, reproduce, and therefore replicate their sister's genes. This genetic system is called haplodiploidy. Roaches on the other hand, are diploids like you and I. The genetic incentive for the cooperation that we see in ants is just not there in roaches. Instead, what the roaches are doing is more similar to reciprocal altruism.

from the article: After much "consultation," through antenna probing, touching and more, the cockroaches divided themselves up perfectly within the shelters. For example, if 50 insects were placed in a dish with three shelters, each with a capacity for 40 bugs, 25 roaches huddled together in the first shelter, 25 gathered in the second shelter, and the third was left vacant.

A completely selfish roach would say "screw you, I'm not going to that other house, I want to stay where everybody else is!". But because other roaches are willing to go to the second house so is any extraordinarily selfish roach. So this is an evolutionarily stable strategy. This challenges how smart we think roaches are. They are truly making decisions. It's not that some of the roaches are genetically predisposed to being the roach who decides not to stay with everyone else while other's lack that genetic predisposition. If this were the case the numbers of each group when they divide would never be even.

Re:Roach Intelligence

[gnovos]

Wouldn't this just be a simple case of emergent behavior? Like, the roach has a simple rule that they follow over and over again, and when the house gets too big that rule proells them to the next house. Like somethign along the lines of:

1) Stay in shelter
2) Count other roaches nearby
3) If otherCount > X move to the next house.

I have heard ants follow this kind of "reasoning" and thus perform very complext tasks.

1) Gather Food
2) If gatherFoodSmell becomes too strong then hunt for food
3) If fellowHunters smell becomes too strong then make tunnel repairs

etc...

Re:Roach Intelligence

[linguizic]

It couldn't be like you describe. All the roaches gather outside the houses and feel around at eachother for a while and then divide and go into the 2 different houses. This requires communication and desicion making. It would be a completely different story if they all tried to cram into one house, and then the ones who couln't fit tried to cram into the other. But that's not what seems to be happening here.

One of the things that this suggests to me is that roaches have good spatial reasoning. If they can make the decision to break up into 2 groups before trying to cram everybody into one of the houses, then they must be able to judge spatial relationships quite well. How many humans can look at a room and say "you could fit 25 humans into that room"?

Computing?

[DahGhostfacedFiddlah]

Given an appropriately-complex apparatus, could one devise a device to utilize the computing power of cockroaches for opimization problems?

The potential of this cock-puter is mind-blowing...

Roach Intelligence - and math skills

[Jtheletter]

For example, if 50 insects were placed in a dish with three shelters, each with a capacity for 40 bugs, 25 roaches huddled together in the first shelter, 25 gathered in the second shelter, and the third was left vacant.

OK, so now let's do this experiment again, this time with 51 roaches. Will there be 17 in each of the three shelters? What if we reduce shelter capacity to 30 roaches? or 25?

As another poster has suggested this may have less to do with intelligent decisions and more to do with scripted behavior: if roach population here is above X, branch to new location. The threshold X may be set by a number of factors such as total perceived population, observed population in the current shelter, etc. Tweaking shelter size, number of roaches, and other conditions in a controlled way may reveal the decision motivators and help to discern if there is some consensus at work or if it's just a survival script. Just as roaches avoid light because they have evolved to recognize it leaves them detectable and therefore vulnerable, they may scorn large groupings to avoid being wiped out by the loss of a single population center.

U.S. Federal Deficit by Political Party

[Futurepower(R)]

Support for the parent statement: U.S. Federal Deficit by Political Party.

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Before, Saddam got Iraq oil profits & paid part to kill Iraqis. Now a few Americans share Iraq oil profits, & U.S. citizens pay to kill Iraqis. Improvement?