Many animals – from locusts to fish – live in groups and swarm, but scientists aren’t sure why or how this behavior evolved. Now a multidisciplinary team of Michigan State University scientists has used a model system to show for the first time that predator confusion can make prey evolve swarming behavior.
Swarming allows groups of animals to accomplish tasks that they can’t do alone, such as defending themselves from a much larger predator.
“There are both costs and benefits to swarming and all other behaviors,” said Christoph Adami, MSU professor of microbiology and molecular genetics. “The benefits are discussed all the time. But the litmus test is whether a behavior evolves because of those benefits. If it doesn’t evolve, it doesn’t mean it’s not beneficial, but if it does evolve, it’s proof that the behavior has benefits that outweigh its costs. Our model system shows that predator confusion was enough of a selection pressure to evolve swarming behavior in prey.”
The paper “Predator confusion is sufficient to evolve swarming behavior,” is published online today by the Journal of the Royal Society Interface.
“In our computational model system, swarming evolved as a defense to exploit the predator confusion effect,” said Randal Olson, computer science graduate student and lead author of the paper. “Rather than seeing just one or two prey when the predators attack, which is what happens when prey scatter, swarming makes the predators see many prey, which confuses them and allows more prey to survive.”
Read more at: Phys.org