The study focuses on the evolution of “eusociality,” a system of collective living in which most members of a female-centric colony forego their reproductive rights and instead devote themselves to specialized tasks – such as hunting for food, defending the nest or caring for the young – that enhance the survival of the group. The study appears in the Proceedings of the National Academy of Sciences.
Eusociality is a rarity in the animal world, said Gene Robinson, a University of Illinois entomology professor and the director of the Institute for Genomic Biology, who led the study. Ants, termites, some bees and wasps, a few other arthropods and a couple of mole rat species are the only animals known to be eusocial.
Among bees, there are the “highly eusocial” honey bees and stingless bees, with a caste of sterile workers and a queen that functions primarily as a “giant, egg-laying machine,” Robinson said. And there are other, so-called “primitively eusocial” insects, usually involving a single mom who starts a nest from scratch and then, once she has raised enough workers, “kicks back and becomes a queen,” he said.
Illinois entomology professor Sydney Cameron, a collaborator on the study and a social insect evolution expert, dislikes the term “primitively eusocial” because it suggests that these bees are on their way to becoming more like stingless bees or honey bees. Eusociality is not a progressive evolution from the “primitive” to the “advanced” stage, she said.
“They’re not striving to become highly eusocial,” Cameron said. “They don’t say to themselves, ‘If only I could become a honey bee!’ ”
“People talk about the evolution of eusociality,” Robinson said. “But we want to emphasize that these were independent evolutionary events. And we wanted to trace the independent stories of each.”
To accomplish this, the researchers worked with Roche Diagnostic Corp. to sequence active genes (those transcribed for translation into proteins) in nine species of bees representing every lifestyle from the solitary leaf-cutter bee, Megachile rotundata, to the highly eusocial dwarf honey bee, Apis florea. Then Illinois crop sciences professor and co-author Matt Hudson used the only available bee genome, that of the honey bee, Apis mellifera, as a guide to help assemble and identify the sequenced genes in the other species, and the team looked for patterns of genetic change that coincided with the evolution of the differing social systems.
“Are there genes that are unique to the primitively eusocial bees that aren’t found in the highly eusocial bees?” Cameron said. “Or if you lump all the eusocial bees together, are there unique genes that unite those groups compared to the solitaries?”
The analysis did find significant differences in gene sequence between the eusocial and solitary bees. The researchers also saw patterns of genetic change unique to either the highly eusocial or primitively eusocial bees. The frequency and pattern of these changes in gene sequence suggest “signatures of accelerated evolution” specific to each type of eusociality, and to eusociality in general, the researchers reported.
“What we find is that there are some genes that show signatures of selection across the different independent evolutions (of eusocial bees),” Robinson said. “They might be representatives of the ‘gotta have it’ genes if you’re going to evolve eusociality. But others are more lineage-specific.”
This study was made possible with a one-gigabyte sequencing grant from 454 Life Sciences (Roche Diagnostics Corp.) by way of the Roche 1GB contest. The National Science Foundation and the National Institutes of Health also supported the research.
The study team also included researchers from Cornell University and from the Program in Ecology, Evolution and Conservation Biology and the Institute for Genomic Biology at Illinois.
Diana Yates | Source: University of Illinois
Further information: www.illinois.edu
More articles from Life Sciences:
Estrogen: Not just produced by the ovaries
05.12.2013 | University of Wisconsin-Madison
Iranian biodiversity was underestimated, several new candidate species found
05.12.2013 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere
The Light: Global study gets underway with online user survey
Light has a fundamental impact on our sense of well-being and performance. In cooperation with Zumtobel, a supplier of lighting solutions, Fraunhofer IAO has launched a global user survey of lighting quality in offices. The objective is to identify the best lighting conditions for a variety of spaces and lighting ...
Quantum entanglement, a perplexing phenomenon of quantum mechanics that Albert Einstein once referred to as “spooky action at a distance,” could be even spookier than Einstein perceived.
Physicists at the University of Washington and Stony Brook University in New York believe the phenomenon might be intrinsically linked with wormholes, hypothetical features of space-time that in popular science fiction can provide a much-faster-than-light shortcut from one part of the universe to another.
But here’s the catch: One couldn’t actually ...
A star is formed when a large cloud of gas and dust condenses and eventually becomes so dense that it collapses into a ball of gas, where the pressure heats the matter, creating a glowing gas ball – a star is born.
New research from the Niels Bohr Institute, among others, shows that a young, newly formed star in the Milky Way had such an explosive growth, that it was initially about 100 times brighter than it is now. The results are published in the scientific journal, Astrophysical Journal Letters.
The young ...
EPFL scientists have shown how to achieve a dramatic increase in the capacity of optical fibers; Their simple, innovative solution reduces the amount of space required between the pulses of light that transport data
Optical fibers carry data in the form of pulses of light over distances of thousands of miles at amazing speeds. They are one of the glories of modern telecommunications technology.
However, their capacity is limited, because the pulses of light need to be lined up one after the other in ...
NASA's Hurricane and Severe Storms Sentinel airborne mission known as HS3 wrapped up for the 2013 Atlantic Ocean hurricane season at the end of September, and had several highlights. HS3 will return to NASA’s Wallops Flight Facility in Wallops Island, Va., for the 2014 Atlantic hurricane season.
During the 2013 mission, two unmanned Global Hawks flew from Wallops for the first time. The mission highlights included studying the Saharan Air Layer, following the genesis of a tropical storm, finding a unique hybrid core or center circulation in a redeveloped storm, obtaining measurements on the strongest side of ...
05.12.2013 | Health and Medicine
05.12.2013 | Ecology, The Environment and Conservation
05.12.2013 | Information Technology
05.12.2013 | Event News
04.12.2013 | Event News
12.11.2013 | Event News