Source: Cornell University

Posted: March 16, 2006

Sociality Of Sweat Bees Evolved Simultaneously During Climate Change

In the first study to link social evolution to climate change, Cornell University entomologists show that the social behavior of many species of sweat bees evolved simultaneously during a period of global warming.


Bryan Danforth, associate professor of entomology, shown here in Ranomafana National Park, Madagascar, studies the evolutionary history, or phylogeny, of the social behavior of halictid bees. (Photo Credit: Ken Walker)

This social evolution occurred much more recently than scientists ever thought -- only 20 million to 22 million years ago, compared with the social evolution of other insects, which evolved more than 65 million years ago.

"We believe that climatic change was a critical factor in the evolution of social behavior in these bees," said Bryan Danforth, associate professor of entomology at Cornell. Sweat bees are eusocial, he explained, which is a type of social behavior in which the animals have permanently sterile worker castes (among other traits). Eusocial animals include honey, bumble, carpenter and sweat (halictid) bees, ants, termites, many wasps as well as certain kinds of shrimp and the naked mole rat.

Danforth's study, to be published in a forthcoming issue of the Proceedings of the Royal Society of London, Series B, Biological Sciences, used both fossils as well as more than 2,300 base pairs of DNA sequences from three genes to infer the evolutionary history, or phylogeny, of the family's eusocial lineages and their relatives. The DNA sequencing sheds light on how divergent the various species are from each other, and the fossils allow the researchers to represent the phylogeny in terms of a timeline in millions of years.

In 2002 and 2004, Danforth showed that the social evolution of the various species of halictid bees arose multiple times independently. The study on the timing of that social evolution, however, began as an honors thesis for former Cornell undergraduate Adam Pearson '03, now a graduate student at the University of Connecticut, in collaboration with Danforth and two former Cornell postdoctoral researchers, Sean Brady and Sedonia Sipes.

"What's so interesting is that the social behavior that's characteristic of these insects arose 'simultaneously,' that is, within 2 million years, which is a very narrow window in evolutionary terms," said Danforth. "It's also news to us that the origin of sociality in halictid bees was so recent."

Once the team dated the evolution of the social behaviors to just 20 million to 22 million years ago, they researched what might have been going on in this time frame that would trigger the development of social behavior in so many species at the same time.

"We discovered that the Earth underwent a warming trend from 15 to 26 million years ago," Danforth said. "In modern halictid bees, social behavior varies among species and even within species as a function of latitude and altitude such that species and populations at low latitudes and in warmer regions are often fully social, whereas they are solitary at higher latitudes and altitudes, which are colder."

Warmer regions have longer growing seasons, he explained, which allows two broods to emerge instead of one. The first brood (workers) helps raise the second brood (reproductives).

Danforth, who teaches Alien Empire: Bizarre Biology of Bugs (Entomology 201), a two-credit course in insect biology, and maintains a Web site on bee phylogeny, http://www.entomology.cornell.edu/BeePhylogeny/, is also struck by the social flexibility of sweat bees.

"Other social insects (such as ants, termites, paper wasps and honey bees) have reached 'a point of no return' in social evolution in which members of the lineage are now unable to revert back to a solitary condition. These insects, however, seem to be able to revert fairly easily," he concluded.

Halictid bees, which are important native pollinators in the Northern Hemisphere, where there are about 1,000 species, are nicknamed sweat bees because they are attracted to the salts in human perspiration.

 

Editor's Note: The original news release can be found here.

 
 

Can't find it? Try searching ScienceDaily or the entire web with:

Google
 
Web ScienceDaily.com

Science Video News


Autism affects between 1 to 3 of every 500 people.  > watch video
Scientists may have found one genetic explanation for Autism, a condition whose causes are largely unknown.  > watch video
These two diseases are linked in surprising ways. What can you do to stay healthy.  > watch video
Glacier could crash into Argentina lake. (March 13)  > watch video
A glacier in Argentina has begun breaking apart.  > watch video
Lion cub Safina is enjoying some domestic comforts and friends before she settles into her...  > watch video

Jump to: < prev | next >

 
 
 

To Survive Their Harsh Environment, Desert Bees Hedge Their Bets With A Wait-And-Wet Attitude, Cornell Researcher Discovers (November 18, 1999) -- Like the desert's floral seeds waiting for their season in the sun, scientists have learned that the desert bees have adopted a patient reproductive strategy. Desert bee larvae patiently lie in wait ... > full story

Researchers Find Link Between Social Behavior, Maternal Traits In Bees (January 8, 2006) -- One of the puzzling questions in the evolution of bees is how some species developed social behaviors. Arizona State University Life Sciences associate professor Gro Amdam thinks part of the answer ... > full story

Bees Solve Complex Colour Puzzles (November 8, 2005) -- Bees have a much more sophisticated visual system than previously thought, according to a new University College London study in which bees were able to solve complicated colour puzzles. The findings ... > full story

Intoxicated Honey Bees May Clue Scientists Into Drunken Human Behavior (October 25, 2004) -- Inebriated bees could give researchers better insight into alcohol's effects on human behavior, a new study ... > full story

Study Sheds Light On Behavior Of Middle-Age 'Undertaker' Bees (September 10, 1997) -- It's a dirty job and only about 1 percent do it at any one time. But middle-aged honey bees that serve as undertakers -- removing dead bees from the hive -- appear to be a distinct cadre of workers ... > full story

Study Of Bees By UC San Diego Biologist Provides Insight Into Evolution Of Bee Communication (September 23, 2003) -- A team of biologists working in Brazil may have found the clues to resolving the longstanding mystery of why some species of bees, such as honey bees, communicate the location of food with dances in ... > full story

Bumblebee See, Bumblebee Do (September 1, 2005) -- Just as travelers figure out which restaurant is good by the numbers of cars in the parking lot, bumblebees decide which flowers to visit by seeing which ones already have bee visitors. The finding ... > full story

Neurosurgical Technique Relieves Excessive Sweating (January 30, 1998) -- Forget that adage about how men sweat but women perspire. We all sweat, and it's a good thing we do. Sweating controls body temperature. As our temperature rises, the sympathetic nervous system ... > full story

Cracking The Olfactory Code In Bees (March 10, 2005) -- Tastes and smells are evocative and play a crucial role in finding food for many animals. A new study of smell perception in honeybees published in the freely-available online journal PLoS Biology ... > full story

Biological Clock Gene In Bees Found To Have Another Function (July 5, 2000) -- A gene associated with the biological clock in many organisms has revealed yet another function. In honeybees, which live in a world with a distinct division of labor, the gene is more active in the ... > full story

Bee sting -- A bee sting in the vernacular means a sting of a bee, wasp or hornet. Some people may even call the bite of a horsefly a bee sting. It is important to differentiate a bee sting from an insect bite. ... > full article

Characteristics of common wasps and bees -- There are many different characteristics of bees and ... > full article

Bee -- Bees are flying insects, closely related to wasps and ants. Bees are extremely important as pollinators in ... > full article

Honeybee -- Honeybees are a subset of bees which fall into the Order Hymenoptera and Suborder Apocrita. Of the approximately 20,000 known species of bees, there are eleven species within the genus Apis, all of ... > full article

Pheromone -- A pheromone is any chemical produced by a living organism that transmits a message to other members of the same species. There are alarm pheromones, food trail pheromones, sex pheromones, and many ... > full article

Chimpanzee -- Chimpanzee, often abbreviated to chimp, is the common name for two species in the genus Pan. The better known chimpanzee is Pan troglodytes, the Common Chimpanzee, living in West and Central Africa. ... > full article

Instinct -- Instinct is the inherent disposition of a living organism toward a particular behavior. Instincts are generally inherited patterns of responses or reactions to certain kinds of stimuli. Instinctive ... > full article

Pollination management -- Pollination Management is the label for horticultural practices that accomplish or enhance pollination of a crop, to improve yield or quality, by understanding of the particular crop's pollination ... > full article

Body odor -- Body odor, Bromhidrosis or body odour is the smell of bacteria growing on the body. These bacteria multiply considerably in the presence of sweat, but sweat itself is almost totally odorless. Body ... > full article

Africanized bee -- Africanized bees, also known as killer bees, are hybrids of the African honeybee with various European honeybees descended from 26 Tanzanian queen bees accidentally released in 1957 in Southern ... > full article

The Winds of Change : Climate, Weather, and the Destruction of Civilizations
The Winds of Change places the horrifying carnage unleashed on New Orleans, Mississippi, and Alabama by Hurricane Katrina in context.Climate has been humanity's constant, if moody, companion. At ... > read more

The Weather Makers : How Man Is Changing the Climate and What It Means for Life on Earth
Sometime this century the day will arrive when the human influence on the climate will overwhelm all other natural factors. Over the past decade, the world has seen the most powerful El Niño ... > read more

Don't Sweat the Small Stuff--and it's all small stuff (Don't Sweat the Small Stuff Series)
Got a stress case in your life? Of course you do: "Without question, many of us have mastered the neurotic art of spending much of our lives worrying about a variety of things all at once." Carlson's ... > read more

The Little Ice Age: How Climate Made History, 1300-1850
"Climate change is the ignored player on the historical stage," writes archeologist Brian Fagan. But it shouldn't be, not if we know what's good for us. We can't judge what future climate change will ... > read more

Motivational Interviewing, Second Edition: Preparing People for Change
Since the initial publication of this breakthrough work, motivational interviewing (MI) has been used by countless clinicians. Theory and methods have evolved apace, reflecting new knowledge on the ... > read more

Beekeeping for Dummies
"The information a beginner needs to keep bees with confidence." Kim Flottum, Bee Culture Magazine "A reader-friendly guide to beekeeping for novices or beginners." Dewey M. Caron, Professor of ... > read more

Winning by Losing : Drop the Weight, Change Your Life
Are you tired of trying one diet program after another only to find them full of gimmicks and empty promises of an easy way out? Are you ready for straight talk on how to get healthy, lose weight, ... > read more

Field Notes from a Catastrophe
An argument for the urgent danger of global warming in a book that is sure to be as influential as Rachel Carson’s Silent Spring.Known for her insightful and thought-provoking journalism, New ... > read more

Environmental Science : Toward a Sustainable Future (9th Edition)
This classic book explores the interactions of humans within the natural environment and probes issues thoroughly, examining their scientific basis, history, and society's response. Strong science, ... > read more

In Search of Memory: The Emergence of a New Science of Mind
Nobelist Eric Kandel's account of how his personal quest to understand memory intersected with the emergence of a new science.In Search of Memory relates the astonishing story of how four different ... > read more

 
 
Text: small | med | large
Also search ScienceDaily or the web with Google:
ScienceDaily.com
Web
 
 
Health & Medicine Mind & Brain Plants & Animals Space & Time Earth & Climate Matter & Energy Computers & Math Fossils & Ruins