Animal of other animal species for food, both of domesticated livestock species in animal husbandry and, mainly at sea, by hunting wild species. Marine fish of many species are caught commercially for food. A smaller number of species are farmed commercially. Invertebrates including cephalopods, crustaceans, and bivalve or gastropod molluscs are hunted or farmed for food. Chickens, cattle, sheep, pigs and other animals are raised as livestock for meat across the world. Animal fibres such as wool are used to make textiles, while animal sinews have been used as lashings and bindings, and leather is widely used to make shoes and
Wild animal suffering nature would be either unethical, unfeasible, or both. In his autobiography, Charles Darwin acknowledged that the existence of extensive suffering in nature was fully compatible with the workings of natural selection, yet maintained that pleasure was the main driver of fitness-increasing behavior in organisms. Evolutionary biologist Richard Dawkins challenged Darwin's claim in his book "River Out of Eden", wherein he argued that wild animal suffering must be extensive due to the interplay of the following evolutionary mechanisms: From this, Dawkins concludes that the natural world must necessarily contain enormous amounts of animal suffering as an inevitable consequence of Darwinian evolution.