Conservation biology emerged in the 1980s to prevent extinctions by intervention and adaptive management. Despite many successes worldwide, the goal of self-sustaining populations of many threatened species without ongoing human assistance remains elusive. This is in part due to novel selection pressures overwhelming the ability of species to adapt to changing ecological circumstances. Evolution was also not considered to occur sufficiently fast to induce the recovery of many species. Recently, however, evolution has been observed in contemporary time frames, often in decades.