In around 300 years time, 75% of all mammal species on Earth will have gone extinct. That’s the startling prediction if current rates of extinction continue and the animals already threatened or endangered are wiped out this century, according to Anthony Barnosky, a palaeobiologist at the University of California, Berkeley.

Barnosky studies biodiversity changes and extinction rates that occurred in the deep past, and compares them to trends happening now. Since life first evolved, billions of years ago, flourished, diversified and made our planet truly distinct from any other we’re aware of, there have been five mass extinctions. Each was triggered by a cataclysmic event and resulted in at least 75% of all species going extinct. The last of these occurred 65 million years ago, when a meteorite slammed into Earth, throwing up persistent clouds of debris that darkened the sky for years. The climate change that followed led to…