Earth sees “biological annihilation” in sixth mass extinction — study

The world is experiencing a “biological annihilation” of its animal species due to “human-caused global environmental problems” in recent decades, a new scientific study has found.
The demise of billions of populations of both rare and common species means the sixth mass extinction event is already well under way and is ”more severe than perceived,” the study published in a peer-reviewed journal, Proceedings of the National Academy of Sciences (PNAS), said.
“In the last few decades, habitat loss, over exploitation, invasive organisms, pollution, toxification, and more recently climate disruption, as well as the interactions among these factors, have led to the catastrophic declines in both the numbers and sizes of populations of both common and rare vertebrate species,” it said.
There have been five “mass extinctions” in the past 500 million years of earth’s history, during which 75 per cent of species disappeared.
The last one was some 66 million years ago, when 76 per cent of all species were lost, including the dinosaurs, due to volcanic activity, climate change and asteroid impact.
The study was conducted by researchers from Stanford University and the National Autonomous University of Mexico.
The study used a sample of 27,600 terrestrial vertebrate species and a more detailed analysis of 177 mammal species that faced population extinction between 1900 and 2015, which showed extremely high degree of population decay in vertebrates, even in species of low concern. — dpa