Humanity’s ongoing annihilation of wildlife is cutting down the tree of life, including the branch we are sitting on, according to a stark new analysis. More than 300 different mammal species have been eradicated by human activities. The new research calculates the total unique evolutionary history that has been lost as a result at a startling 2.5bn years.Furthermore, even if the destruction of wild areas, poaching and pollution were ended within 50 years and extinction rates fell back to natural levels, it would still take 5-7 million years for the natural world to recover.Many scientists think a sixth mass extinction of life on Earth has begun, propelled by human destruction of wildlife, and 83% of wild mammals have already gone. The new work puts this in the context of the evolution and extinction of species that occurred for billions of years before modern humans arrived.