Navigation Links
Flocking together: Study shows how animal groups find their way

A study led by Princeton biologists has revealed a remarkably simple mechanism that allows flocking birds, schooling fish or running herds to travel in unison without any recognized leaders or signaling system.

The finding, published in the Feb. 3 issue of Nature, helps settle age-old questions about how animals coordinate their actions. Previously, scientists had looked for subtle signals or other explicit systems that animals may use in disseminating information through groups. The new study showed that such complexity is not necessary: Large groups easily make accurate decisions about where to go even when no individuals are regarded as leaders and very few individuals have any pertinent information.


In addition to shedding light on the graceful coordination of animal groups, the results may be useful in understanding how humans behave in crowds and in designing robots that explore remote locations such as the ocean or other planets.

"When you see apparently complex behaviors, the mechanisms that coordinate these behaviors may be surprisingly simple and generic," said Iain Couzin, a postdoctoral researcher in Princeton's Department of Ecology and Evolutionary Biology and lead author of the study.

Using computer simulations, the researchers found that group coordination arises naturally from two basic instincts: the need to stay in a group; and the desire by some individuals to act on their own information about where to go. First, the researchers programmed their simulated animals with a basic urge to stay near others, but not collide with them. This instinct alone caused individuals to form close-knit, evenly spaced groups like those of real animals, which pay a high price -- such as being eaten -- if they stray from their group.

Second, a few animals were programmed to have a preferred direction, as if aware of a food source or other valued destination. These animals were instructed to balance their desire to move t oward their goal with their desire to stay in the group. In repeated simulations, it required only a few individuals with specific goals to set hundreds of others on the same course.

"It demonstrates the power of the little guy," said Daniel Rubenstein, chair of ecology and evolutionary biology. "You don't need avowed leaders, you don't need complex signaling."

In the simulations, a small number of "informed" individuals was just about as effective in leading a large group as a small one. When the size of the group increased from 10 to 200, the percentage of informed individuals needed to accurately guide the group reduced from approximately 50 percent to less than 5 percent. As a result, the number of informed individuals required to lead a small group was about the same as the number needed to lead a large one, Couzin said

The researchers extended their experiments by introducing two subgroups with differing preferences about which direction to move. The overall group consistently chose the direction preferred by the bigger subgroup even if the two subgroups differed in size by only one member, demonstrating that groups can come to an accurate consensus decision even though individuals are not aware of the preferences of others or whether they are in a majority or minority.

Couzin, who divides his time between Princeton and Oxford University, collaborated with Simon Levin of Princeton as well as Jens Krause of the University of Leeds and Nigel Franks of the University of Bristol.

In addition to its biological insights, the research may provide ideas for designing robots that work together in groups, said Couzin, who has collaborated with roboticists at Princeton on designs for fleets of underwater vehicles.

"Say you had a group of robots exploring a planet or the ocean, and each individual robot was moving around collecting information locally," he said. "By returning to the group and following the type of algorithm we propose, they could select collectively the direction associated with the best quality information or select collectively the majority direction."

Couzin and colleagues are now testing their findings in experiments with animals, such as schools of fish in which a few have been taught to seek food in a certain location. He also believes the results may shed light on how people move in crowds and is currently organizing experiments that test the principles in large groups of student volunteers.


'"/>

Source:Princeton University


Related biology news :

1. Novel Asthma Study Shows Multiple Genetic Input Required; Single-gene Solution Shot Down
2. Emory Study Tests Bone Marrow Stem Cells to Improve Circulation in Legs
3. UCLA Study Shows One-Third of Drug Ads in Medical Journals Do Not Contain References Supporting Medical Claims
4. Study Demonstrates Gene Expression Microarrays are Comparable and Reproducible
5. Study Links Ebola Outbreaks To Animal Carcasses
6. Breakthrough Microarray-based Technology for the Study of Cancer
7. NYU Study Reveals How Brains Immune System Fights Viral Encephalitis
8. Study finds more than one-third of human genome regulated by RNA
9. Leukemia Drug Breakthrough Study In New England Journal Of Medicine
10. Study identifies predictors of HIV drug resistance in patients beginning triple therapy
11. New Study from Affymetrix Laboratories Points to Changing View of How Genome Works
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/9/2016)... UAE, May 9, 2016 Elevay ... comes to expanding freedom for high net worth professionals ... in today,s globally connected world, there is still no ... could ever duplicate sealing your deal with a firm ... passports by taking advantage of citizenship via investment programs ...
(Date:4/28/2016)... -- First quarter 2016:   , Revenues ... first quarter of 2015 The gross margin was 49% ... and the operating margin was 40% (-13) Earnings per ... from operations was SEK 249.9 M (21.2) , Outlook ... 7,000-8,500 M. The operating margin for 2016 is estimated ...
(Date:4/19/2016)... The new GEZE SecuLogic access ... "all-in-one" system solution for all door components. It can ... door interface with integration authorization management system, and thus ... minimal dimensions of the access control and the optimum ... offer considerable freedom of design with regard to the ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... SAN FRANCISCO , June 23, 2016   ... it has secured $1 million in debt financing from ... to ramp up automation and to advance its drug ... for its new facility. "SVB has been ... goes beyond the services a traditional bank would provide," ...
(Date:6/23/2016)... , ... June 23, 2016 , ... STACS DNA Inc., ... Leader at the Arkansas State Crime Laboratory, has joined STACS DNA as a Field ... DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. “In further expanding ...
(Date:6/23/2016)... , June 23, 2016 Apellis ... Phase 1 clinical trials of its complement C3 ... single and multiple ascending dose studies designed to ... (PD) of subcutaneous injection in healthy adult volunteers. ... (SC) either as a single dose (ranging from ...
(Date:6/23/2016)... Andrew D Zelenetz ... Published recently in Oncology ... touchONCOLOGY, Andrew D Zelenetz , discusses the ... is placing an increasing burden on healthcare systems ... With the patents on many biologics expiring, interest ...
Breaking Biology Technology: