Yuval Noah Harari in The Guardian:
Animals are the main victims of history, and the treatment of domesticated animals in industrial farms is perhaps the worst crime in history. The march of human progress is strewn with dead animals. Even tens of thousands of years ago, our stone age ancestors were already responsible for a series of ecological disasters. When the first humans reached Australia about 45,000 years ago, they quickly drove to extinction 90% of its large animals. This was the first significant impact that Homo sapiens had on the planet’s ecosystem. It was not the last.
About 15,000 years ago, humans colonised America, wiping out in the process about 75% of its large mammals. Numerous other species disappeared from Africa, from Eurasia and from the myriad islands around their coasts. The archaeological record of country after country tells the same sad story. The tragedy opens with a scene showing a rich and varied population of large animals, without any trace of Homo sapiens. In scene two, humans appear, evidenced by a fossilised bone, a spear point, or perhaps a campfire. Scene three quickly follows, in which men and women occupy centre-stage and most large animals, along with many smaller ones, have gone. Altogether, sapiens drove to extinction about 50% of all the large terrestrial mammals of the planet before they planted the first wheat field, shaped the first metal tool, wrote the first text or struck the first coin.
The next major landmark in human-animal relations was the agricultural revolution: the process by which we turned from nomadic hunter-gatherers into farmers living in permanent settlements. It involved the appearance of a completely new life-form on Earth: domesticated animals. Initially, this development might seem to have been of minor importance, as humans only managed to domesticate fewer than 20 species of mammals and birds, compared with the countless thousands of species that remained “wild”. Yet, with the passing of the centuries, this novel life-form became the norm. Today, more than 90% of all large animals are domesticated (“large” denotes animals that weigh at least a few kilograms).