Migration can both promote, inhibit cooperation among animals

Aug. 9 (UPI) -- Migration can help species thrive by generating the ideal spatial distribution for cooperation, according to a new mathematical model. Migration can also, however, inhibit cooperation, fueling a species' downfall.

Felix Funk and Christoph Hauert, researchers at the University of British Columbia, developed a mathematical model to better understand the evolution of migration and cooperation.

For most species to thrive, a baseline level of cooperation is necessary. Every organism, from humans to microbes, must work to maintain shared resources, like potable water and available nutrients. If too many individuals pursue selfish ends, the entire population can suffer.

"The effect of collective movement is especially significant when triggered in response to the generation of public goods," researchers wrote in their new paper on the subject. "Microbial communities can, for instance, alter their environment through the secretion of extracellular substances. Some substances provide antibiotic-resistance, others provide access to nutrients or promote motility."

Migration highlights this social conflict because defectors can take advantage of cooperators while avoiding the consequences of their selfish behavior. But as the latest research showed, migration can also enable the kinds of spatial distribution patterns that promote cooperation and the maintenance of shared resources.

The new model showed that when cooperators migrate toward other cooperators, they can form cohesive communities in which public goods thrive and the organisms that rely on them thrive. However, when defectors migrate toward cooperators, their selfish plundering can wreck communities.

The analysis, published this week in the journal PLOS Computational Biology, showed avoiding or running away from defectors is counterproductive. Cooperators avoiding the bad seeds can spread themselves thin, hurting their ability to maintain a cohesive community.

"Our model was inspired, in particular, by naturally occurring modes of directed migration, such as chemotaxis, which allows microbes to locate attractive regions while steering clear of detrimental ones," Funk, who specializes in predictive modelling of biological systems, said in a news release. "Our findings could inform future experimental designs to study the role of migration in the development of antibiotic resistance."