Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Communal living of the insect kind

17.11.2011
The social lives of ants, wasps and bees have long been a puzzle to scientists. How did complex insect societies — colonies ruled by a queen and many workers — come to be? A new model adds to discontent with old ideas.

Social insect society is divided into specialized castes that take on different roles within the nest. Most of the members of a colony – the workers – forego their own chance for reproduction and instead spend their lives raising offspring that aren't their own. Generations of scientists have tried to understand why. In other words, "what's in it for the workers?" said author James Hunt, who developed his model while at the National Evolutionary Synthesis Center in Durham, NC.

The question continues to spark debate. For the past 40 years, the dominant answer was based on the idea that having kids of your own isn't the only way to pass on your genes. According to a theory called Hamilton's rule, proposed in 1964 by British biologist William Hamilton, sometimes helping a relative can spread more of your genes to the next generation than having kids of your own. When the benefits to a queen outweigh the costs to her workers, the theory goes, altruism can evolve.

But there's one thing Hamilton's rule fails to consider. "Direct benefit to the worker is not part of the equation," Hunt said. According to Hunt, the evolutionary beginnings of worker behavior may be more selfish than they seem.

He bases his ideas on more than three decades of research on a family of wasps called the Vespidae, which is made up of nearly 5000 species. The majority of those species live alone, but some —such as hornets, yellowjackets, and paper wasps — live in complex societies with specialized castes that take on different tasks within the nest.

In paper wasps, for example, workers help build and defend the nest where they were born and feed and care for the larvae. By helping out around the nest, worker paper wasps are able to stock up on the food they need to eventually leave and lay eggs on their own, and the queen gets some babysitting help in return. "It's a situation of reciprocal exploitation," Hunt said.

Debates over how social behavior comes to be can be notoriously fierce in scientific circles. In recent years, a handful of studies have thrown Hamilton's rule into question, including a 2010 paper in the journal Nature that inspired dozens of scientists to write replies. Hunt's hypothesis says the 2010 study is basically correct, but it overplays the importance of genes.

Much of the debate stems from a failure to parse out key intermediate steps in the evolutionary transition from solitary to social, Hunt says. Paper wasps, for example, cooperate to care for young, but haven't yet evolved the distinct differences in appearance that characterize castes in the most highly social insects.

At these earliest stages, Hunt says, it doesn't matter whether workers and queens are related or not, or how many genes they share. The workers could be lingering around the nest simply because they're looking out for number one.

"The model that I'm putting forward proposes that at the very beginning of social behavior, the workers and the queens are both acting in their own self-interest," Hunt said.

The study will be published this week in the Journal of Evolutionary Biology.

CITATION: Hunt, J. "A conceptual model for the origin of worker behaviour and adaptation of eusociality." Journal of Evolutionary Biology.

For previous stories about this research and related work, read Zimmer, C. 2010. Scientists square off on evolutionary value of helping relatives. The New York Times. http://www.nytimes.com/2010/08/31/science/31social.html?_r=1

The National Evolutionary Synthesis Center (NESCent) is a science center dedicated to cross-disciplinary research in evolution. Funded by the National Science Foundation, NESCent is jointly operated by Duke University, The University of North Carolina at Chapel Hill, and North Carolina State University.

Robin Ann Smith | EurekAlert!
Further information:
http://www.nescent.org

More articles from Life Sciences:

nachricht Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg

nachricht Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>