“Has the Earth’s sixth mass extinction already arrived?” This question – the title of a review published in last week’s Nature – immediately sparked a flurry of news reports about an impending ecological catastrophe on a scale not seen in 65 million years. We are not witnessing a die-off as severe as any of the “Big Five” prehistoric cataclysms just yet, but the continued, gradual loss of threatened species is bringing us ever closer to the tipping point. We can either take action and stave off this large-scale disaster, or simply wait for it to happen.

Of course, extinction is