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!
Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
26.04.2017 | Materials Sciences
26.04.2017 | Agricultural and Forestry Science
26.04.2017 | Physics and Astronomy