Our planet hasn't seen the current rate of extinction since the demise of the dinosaurs 65 million years ago, and global conservation efforts are failing to halt this. As a society, we face choices which will determine the fate of Earth's estimated 8.7 million species, including humans. As wildlife declines, conservation needs to make trade-offs. But what should we conserve and why? Are we wrong to love bees and hate wasps? Are native species more...