A little alone time: Social isolation can benefit some animals

Researchers have investigated how social isolation in the short term may benefit an animal’s long-term development. For some animals, such as ants, toads, and primates, isolation may be vital to natural selection and evolution.

Nathan Bailey of the University of St Andrews in Scotland and Allen Moore of the University of Georgia have identified the critical role that isolation plays among some animal populations.

“The environment an animal experiences can influence which genes it expresses, when, and how much, so conditions of social isolation might cause expression of different traits,” said Bailey. “This in turn could affect responses to natural selection in terms of survival and reproduction, which has evolutionary consequences. For some species, it might even mean that temporary social isolation is favorable.”

For example, the invasive cane toad Rhinella marina of Australia expands into new territory on its own. As a result, members of the opposite sex are extremely attracted to the toad upon its return, boosting the likelihood of both communication and successful mating. In this case, social isolation itself promotes the conditions for natural selection.

“Traits expressed during social interactions might exist because they’ve been shaped by selection, but at the same time, social interactions themselves represent a type of environment that can select and shape how individuals behave,” explained Bailey.

The team has proposed the development of an “index of social isolation,” which would enable experts to measure the ideal amount of isolation that would help specific animals to thrive.

“To understand how short-term social isolation experienced by individual animals translates into trans-generational evolutionary impacts for a larger population, we need a number, something measurable that we can compare across different species and contexts,” said Bailey. “After all, isolation that has negative effects for one species could in fact be beneficial for another.”

The study is published in the journal Trends in Ecology & Evolution.

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By Chrissy Sexton, Earth.com Staff Writer

Image Credit: Nathan W. Bailey