Thousands of plants and animals worldwide are listed as threatened or endangered, but the point of no return for these diminishing populations has been impossible to predict. A new study suggests a way to determine when extinction becomes inevitable.

If the findings from a laboratory experiment prove applicable in nature, they could help ecologists step in to save species before it's too late, researchers say. For now, the study is the first step in moving a mathematical theory into the real world, where endangered species are vanishing at a rate that may range from 10 to 100 times the so-called background extinction rate.  [ Read "Mass Extinction Threat: Earth on Verge of Huge Reset Button? " ] - [ LIVE SCIENCE ]