Earth's sixth mass extinction event already underway: Study

A "biological annihilation" of wildlife over recent decades shows a sixth mass extinction in Earth's history is already underway, as per researchers. Nearly half of the 177 mammals surveyed lost over 80% of their distribution between 1900 and 2015. Scientists attributed the increased loss of wildlife to human overpopulation, overhunting, habitat destruction, and climate change among other factors.