Most people overestimate the extent of wildlife on Earth, yet today there are astonishingly few mammals—and even birds—living in their original habitats. How many? Nature and animal protection associations have been emphasizing for decades how damaging the way and extent to which humans intervene in Earth's ecosystem is. Deforestation, inappropriate agricultural practices, or even the excessive destruction and displacement of certain animal species from their original habitats cause irreversible damage to our planet. As laypeople and simple news consumers, most of us find it difficult to understand the significance of all this, but a few shocking statistics can sober us up. One such statistic points to the current proportion of wild mammals, a group that humanity has thoroughly transformed over the millennia. After the extinction of dinosaurs 66 million years ago, mammals became the dominant land animal group. Our ancestors were among them, but the emergence of hominids (humans) ...