Red harvester ants transmit information through a social network that mirrors human Facebook usage.
Especialistas de la Universidad de Stanford, California (EE. UU.), probaron que el prototipo de la red social FACEBOOK ya existía hace unos 110 a 130 millones de años.
Un estudio realizado por los científicos sobre las colonias de hormigas recolectoras ('pogonomyrmex barbatus'), una especie típica en los desiertos del suroeste de EE. UU., reveló que para establecer la comunicación entre los miles de ejemplares que forman una colonia se aplican los mismos principios que emplean los usuarios de Facebook para comunicarse entre sí.
La mayoría de los usuarios de Facebook está en contacto con un número relativamente reducido de amigos. Pero hay unos cuantos que tienen miles de amigos y funcionan como 'centros informativos': en cuanto cuelgan un mensaje, mucha gente lo ve.
Resulta que durante los millones de años de evolución de las hormigas recolectoras el esquema que han usado ha sido el mismo. Como todas las hormigas, las 'pogonomyrmex barbatus' usan señales químicas para intercambiar de información. Segregan sustancias sobre sus exoesqueletos. Sus compañeros de nido frotan los exoesqueletos con sus antenas y así leen estos mensajes. Una combinación particular de sustancias químicas en el exoesqueleto del insecto dice qué tipo de funciones efectúa este ejemplar: si es una patrulla o un forrajeador, dónde ha estado y qué comida ha encontrado.
La interacción social más intensiva suele tener lugar en la 'sala de entrada' de una colonia.
Las hormigas de patrulla salen fuera para averiguar si en las cercanías hay depredadores o cualquier otro tipo de amenaza. Si la mayoría vuelve, le dan la señal a las hormigas forrajeadoras de que no hay peligro y que se puede salir y cazar alimentos.
Los especialistas de Stanford descubrieron que la mayoría de los insectos comparte información con un número bastante limitado de sus compañeros de nido, pero hay unas cuantas hormigas que llevan la información a una amplia red de compañeras.
Los científicos edificaron un simulacro en el laboratorio de una colonia. Colocaron allí a los insectos y, tras concluir el período de adaptación, grabaron un vídeo en la entrada del hormiguero y lo sometieron a un análisis a través de un programa de ordenador. El programa identificó a todos los insectos y contó cuántos toques de antenas con un compañero efectuó cada uno de ellos durante el experimento.
El análisis reveló que la mayoría de las hormigas tuvo unas 40 interacciones, mientras que un 10% de los insectos funcionaba como 'centro informativo' y contactó con más de 100 ejemplares.
El método del efecto dominó en la comunicación, evidentemente, probó su eficacia. Desde hace millones de años permite a las colonias responder rápidamente a desastres naturales y ataques de depredadores.
Los especialistas de Stanford descubrieron que la mayoría de los insectos comparte información con un número bastante limitado de sus compañeros de nido, pero hay unas cuantas hormigas que llevan la información a una amplia red de compañeras, como ciertos usuarios de facebook: el anuncio se extiende muy rápidamente por toda la red !!!
Ants at FACEBOOK in forest
(PhysOrg.com) -- A recent study in the Journal of the Royal Society Interface presents findings that show that not all ants are as social as others. Similar to your friends on Facebook, some ants communicate with only a few fellow ants, while others are social butterflies and communicate with a much larger circle.
Proven To Kill All Ants - Safe organic - kill fire, black ant Kill ants in 3 days. Guaranteed! - www.antbuster.com
A team of researchers at Stanford University, led by biologist Noa Pinter-Wollman studied the interactions of the red harvester ants (Pogonomyrmex barbatus), native to the deserts of the American Southwest.
All ants utilize a system of chemical signals to communicate. Molecules are secreted through their exoskeletons and are transferred to other ants in the colony when their antennae rub the molecules. This allows them to share information such as where they have been, any food sources they may have found, or if predators are in the area.
Using a mock chamber entrance, the team of researchers measured the information exchange between ants from two different colonies.
Videotaping the exchanges, the team then used a computer program designed to identify each individual ant and count its interactions with others. A total of 4628 interactions were recorded.
On average, each ant had around 40 interactions. However, around 10 percent of the ants made more than 100 contacts with other ants. Further research is examining just what makes these more social ants different than the others within the colonies.
The researchers compare this type of socialization to that seen on sites like Facebook.
While most people have a relatively small number of Facebook friends, there are some with a friends list in the thousands. It is these friends that act as a sort of information hub, spreading information out to a large number of readers. These particular ants are functioning as a large social hub of information.
More information: The effect of individual variation on the structure and function of interaction networks in harvester ants, J. R. Soc. Interface, Published online before print April 13, 2011; doi: 10.1098/rsif.2011.0059 http://rsif.royals … 059.abstract
Ant's social network similar to Facebook - Similar to your friends on Facebook, some ants communicate with only a few ... the team of researchers measured the information exchange between ants from ...
www.physorg.com/.../2011-04-ants-social-network-similar-facebook.html - En caché
The effect of individual variation on the structure and function of interaction networks in harvester ants
Social insects exhibit coordinated behaviour without central control. Local interactions among individuals determine their behaviour and regulate the activity of the colony. Harvester ants are recruited for outside work, using networks of brief antennal contacts, in the nest chamber closest to the nest exit: the entrance chamber. Here, we combine empirical observations, image analysis and computer simulations to investigate the structure and function of the interaction network in the entrance chamber. Ant interactions were distributed heterogeneously in the chamber, with an interaction hot-spot at the entrance leading further into the nest. The distribution of the total interactions per ant followed a right-skewed distribution, indicating the presence of highly connected individuals. Numbers of ant encounters observed positively correlated with the duration of observation. Individuals varied in interaction frequency, even after accounting for the duration of observation. An ant's interaction frequency was explained by its path shape and location within the entrance chamber. Computer simulations demonstrate that variation among individuals in connectivity accelerates information flow to an extent equivalent to an increase in the total number of interactions. Individual variation in connectivity, arising from variation among ants in location and spatial behaviour, creates interaction centres, which may expedite information flow.
This pattern of interactions matches how humans share information on social networking sites like Facebook, says the study's lead author, biologist Noa Pinter-Wollman. Most Facebook users are connected to a relatively small number of friends. A handful of users, however, have thousands of friends and act as information hubs. "As soon as they post something, a lot of people will see it."
Indeed, computer simulations of the ants' social networks showed that information flows fastest when a small number of individuals act as information hubs. Fast-flowing information allows ant colonies to respond faster to threats such as predators and weather hazards, Pinter-Wollman says. "If a lizard comes into the nest, you want to make sure everyone knows about it and goes into hiding.”
But there are also trade-offs. Previous studies in honeybees, which have a similar social structure, found that infectious diseases travel through the same networks as information. These well-connected ants might have an advantage in responding to threats, but they are also more vulnerable to infectious diseases, which can spread quickly through the colony.
Understanding these social networks is the key to understanding ant behavior, Pinter-Wollman says. Ants will decide to forage for food, tend to larvae, or hide from predators based on how frequently they encounter other ants and the chemicals they use. "These interactions are the main things that determine how a colony behaves," she says.
"These results mirror what we know about human social contact and technological networks," says Melanie Moses, a network scientist at the University of New Mexico, Albuquerque. "[These ants] are another empirical system we can look to for answers about how natural selection has been able to build these complex networks."
Deborah M Gordon
Birthday: December 30, 1955
Q&A with Harvester Ant Expert Deborah Gordon
Biologist Deborah Gordon has spent over 20 years studying the harvester ant, a species native to Arizona. She has focused on the ants' colonies—how they survive, thrive, and how each ant takes on different roles depending on the needs of the colony. Here's what she had to say about her research and what we can learn from the ant.
Q: Was it an interest in ants that led to you studying them, or was it an interest in learning about organization and patterns that drew you to ants?
A: I was interested in complex systems like embryos, brains, and ant colonies. No one is in charge, there is no central control, and the components (cells, neurons, ants) act in response to local information. I chose ants because you can see everything that's going on, which is more difficult in an embryo or a brain.
Q: Your work has focused on harvester ants—are they representative of many different ant species?
A: There are more than 11,000 species of ants and they are probably all different. Only a tiny proportion of these species have been studied. So we don't really know how representative any particular species is.
Q: Harvester ants switch jobs depending on the needs of the colony. This is different from bees, for instance, where each has one job its entire life Do you think one method is better than another, or is it like comparing apples and oranges?
A: A bee does not have one job its entire life. Like ants, bees move from one task to another. Younger honeybees work inside the nest and when they are older, they go outside to forage.
Q: Have you been bitten by a harvester ant? I hear they really sting.
A: Harvester ants have a very toxic sting. Yes, I have been stung! But they are not aggressive so it's not that difficult to stay out of the way.
Q: What is the most exciting discovery you've made in your research?
A: There are two: 1) Ants use the rate at which they interact to decide what to do. 2) Older, larger colonies act different from younger, smaller ones. Since ant turnover is high, the ants in old colonies are the same age as the ants in young ones. This means the behavior of older colonies is not due to the experience of older, wiser ants. I think instead it's an effect of colony size; in fact this is what led me to discover that interaction rates depend on colony size.
Q: Ants have been portrayed as almost noble creatures—hard-working, intelligent, and even capable of a strong military. Would you agree with that assessment, at least when it comes to harvester ants?
A: They are hard-working. Watching ants, I am never impressed with their intelligence. Of course ants don't have a military, and is a strong military noble?
Q: Is it difficult to detach yourself from a colony once you've been studying it for so long? Do you start to feel almost protective of it?
A: Harvester ant colonies live for about 25 years and colonies have different personalities. I've gotten to know some colonies well and I definitely like some more than others. I don't really feel protective, though—the ants are good at taking care of themselves.
Q: How can you translate what you've learned about harvester ants in a way that's beneficial to our community?
A: I'm interested in the analogies between interaction networks in ant societies and other societies.
Q: What skills do you need to have in order to study ants? I imagine patience is one of them.
A: It helps to like small things. It does take a kind of patience, or willingness to slow down, to get interested in what is going on in the ants' world.
Q: What other insects have you studied?
A: Other kinds of ants—right now we are also studying the invasive Argentine ant in California and some ants that live as mutualists with trees in tropical forests.
Sunrise refracts over the Peloncillo Mountains, sending tendrils of light along the ground where biologist Deborah Gordon kneels in the dirt with an aspirator, sucking up dozens of ants. We’re in the desert a few hours drive from Tucson, where Arizona meets New Mexico, a sandy intersection that has provided the material for Gordon’s career-long quest to understand the social structure of this particular species of harvester ant, pogomyrmex barbatus. “Hitler could come to power and I wouldn’t know it,” Gordon murmurs, adjusting her wide-brimmed straw hat. “I’d be out here, sucking up ants.” aliciapatterson.org/
Gordon’s work — trying to see how a colony becomes more than a collection of its parts — is central to mysteries of life and science. Her genetic mapping work is a first in her field.