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 Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>