Climate change, species extinctions and tipping points

Typography

Researchers from North Carolina State University have created a model that mimics how differently adapted populations may respond to rapid climate change. Their findings demonstrate that depending on a population's adaptive strategy, even tiny changes in climate variability can create a "tipping point" that sends the population into extinction.

Carlos Botero, postdoctoral fellow with the Initiative on Biological Complexity and the Southeast Climate Science Center at NC State and assistant professor of biology at Washington State University, wanted to find out how diverse populations of organisms might cope with quickly changing, less predictable climate variations. 

Researchers from North Carolina State University have created a model that mimics how differently adapted populations may respond to rapid climate change. Their findings demonstrate that depending on a population's adaptive strategy, even tiny changes in climate variability can create a "tipping point" that sends the population into extinction.

Carlos Botero, postdoctoral fellow with the Initiative on Biological Complexity and the Southeast Climate Science Center at NC State and assistant professor of biology at Washington State University, wanted to find out how diverse populations of organisms might cope with quickly changing, less predictable climate variations. 

"Organisms tend to adopt a strategy for dealing with changes in their environment," Botero says. "Some of them adjust their gene expression either at birth or throughout their lifetime, which we refer to as irreversible and reversible plasticity. Some do what we call 'bet-hedging,' producing offspring that are adapted to one of two possible outcomes so that at least half of their offspring survive, and some rely on plain old evolution - which we call adaptive tracking - to keep up with environmental changes. We wanted to determine which strategies worked best under certain circumstances, and find the point at which that strategy would no longer be viable."

Botero and colleagues Franz Weissing from the University of Groningen, Netherlands, Jonathan Wright from the Norwegian University of Science and Technology and Dustin Rubenstein from Columbia University, created virtual organisms that were able to modify their insulation - or how they might respond to temperature changes through coat thickness, sweating, etc. - to adapt to the environment, and then placed them in simulations with areas of fast and slow temperature variation and high and low predictability.

The results mapped to a series of "zones" where each adaptive strategy worked best. For example, organisms that used reversible plasticity as a strategy did better in a highly predictable environment, even if the rate of environmental change was rapid. Organisms that relied on adaptive tracking, however, did fine regardless of predictability, as long as the rate of change was slow.

Lonely monkey image via Shutterstock.

Read more at EurekAlert.