Collapsed Populations Can Return but May Never be the Same


A distressed species the leaves may return but will likely never be the same. Photo credit: pjan vandaele/Creative Commons

Human activity creates countless disturbances in ecosystems around the world. Everything from the introduction of disease to habitat destruction, pollution to temperature changes have the power to alter local environments and, sometimes, even lead to the complete collapse of certain populations.

What happens when these disturbances are removed, however, remains somewhat unknown. Now, new research offers a hint—and unfortunately, the outlook for impacted ecosystems is not good.Tucker Gilman, a researcher at the National Institute for Mathematical and Biological Synthesis, created a mathematical model that simulated ecological disturbances and the mechanisms that lead to hybridization of a species.

What he found was that when disturbances are removed, collapsed populations can rebound but often it is too late to preserve the ecosystem's original biodiversity. "The model shows," Gilman explains, "that populations after collapse are likely to be different from the parental populations in ways that affect the future evolution of the system."

Disturbances that led to population declines caused hybridization, which, he says, eventually results in smaller populations and less genetic diversity across the ecosystem—even when disturbances are later removed.

"The encouraging news from an ecosystems service point of view is that, if we act quickly, we may be able to refill ecological niches emptied by species collapse," Gilman says, "however, even if we can refill the niches, we probably won't be able to bring back the same species that we lost."

Read more about extinction:
20% of World's Plant Species Threatened With Extinction - Yes, Human Activity is Main Cause
Could a Math Formula Save Species from Extinction?
Humans Pushing Extinction Rates Up Faster Than Species Can Evolve - Will Hit 10,000x Historic Rates

Tags: Animals | Conservation | Endangered Species