Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ant colonies shed light on metabolism

27.08.2010
Ants are usually regarded as the unwanted guests at a picnic.

But a recent study of California seed harvester ants (Pogonomyrmex californicus) examining their metabolic rate in relation to colony size may lead to a better appreciation for the social, six-legged insects, whose colonies researchers say provide a theoretical framework for understanding cellular networks.

The Study

A team of researchers led by James Waters of Arizona State University in Tempe, Ariz. conducted a series of experiments designed to measure the components of ant metabolism, such as oxygen and carbon dioxide, in individual ants and in colonies of ants. The team studied 13 colonies of seed harvester ants taken from a nearby desert and housed in the university’s research lab. By using flow-through respirometry and factors such as growth rates, patterns of movement, behavior and size, the team measured standard metabolic rates (i.e., energy expenditures) of the functioning colonies as well as in individual ants.

The researchers found that the metabolic rate of seed harvester ant colonies could not be predicted by adding and dividing the by-products of the metabolisms of all individual colony members. In fact, the colony as a whole produced only 75% of the by-products that its individual members would produce individually if each ant lived alone. Thus, the colonies’ metabolism was less than the sum of all the individual ants’ metabolisms.

The team also found that the larger the colony, the lower its overall metabolic rate. “Larger colonies consumed less energy per mass than smaller colonies,” said Mr. Waters. “Size affects the scaling of metabolic rate for the whole colony.”

Colony size appeared to influence patterns of behavior and the amount of energy individual ants spent. “In smaller colonies, more ants were moving fast, and there was a more even distribution of fast-moving ants,” said Mr. Waters. “But in larger colonies, there were more ants that moved more slowly, and fewer that were moving really fast.”

That the distribution of individual walking speeds became less uniform as colony size increased suggests that disparities in effort among individuals increased with colony size.

An Exciting Ratio

The 0.75 scaling exponent for colony metabolic rate strikes Mr. Waters as important because it indicates that colony metabolism is influenced in a way similar to what most individual organisms experience.

“As creatures go from small to large, their mass-specific metabolic rate decreases. It’s a broad pattern in biology,” he said. “When you graph these patterns, you can see how metabolism decreases as a creature gets bigger, and the exponent is usually near 0.75.”

Yet a colony of ants experienced this decline as though it was one single “super-organism”. Mr. Waters noted that the team isn’t sure why this is so, but he has a few ideas.

“Ants need to stay in contact with each other in a colony, and it’s possible that in larger colonies, certain ants take on the role of a network hub to keep the other ants in the colony more in touch with each other,” he said. “That would relax the demand placed on the other ants.”

He added that a larger size might afford a colony a division of labor not possible in a smaller colony. Individuals in a smaller colony would have to work harder to satisfy basic energy demands.

Implications

According to Mr. Waters, because ant colonies behave metabolically like individual organisms, studying how a colony’s size changes its metabolism could offer useful insight for developing theories about medication dosage in humans.

“It’s hard to figure out how size affects metabolic rate in individuals because it’s not easy to change an individual’s size,” he said. “With an ant colony, it’s as easy as adding or removing individual ants.”

This is not to say that ant colonies function like individual humans. Rather, ant colonies could serve as a model for testing theories about the role of networks among cells in human metabolism.

“We’ve got this pattern where the larger an organism is, the slower its metabolism, and we don’t really understand why,” said Mr. Waters. “It’s important to find out because we really don’t have any sort of theoretical basis for deciding the right dose of medication. We can do charts on weight, and we can run tests on animals, but it’s really more alchemy than science.”

Mr. Waters presented his paper, Scaling of Metabolism, Growth and Network Organization in Colonies of the Seed Harvester Ant, Pogonomyrmex californicus, at the American Physiological Society’s Intersociety Meeting Global Science: Comparative Physiology in a Changing World. The program is located at http://the-aps.org/meetings/aps/comparative/preprogram.htm.

NOTE TO EDITORS: To arrange an interview with Mr. Waters, please contact Donna Krupa at dkrupa@the-aps.org or 301-634-7209

Donna Krupa | EurekAlert!
Further information:
http://www.the-aps.org

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>