Felidae carnivores, meaning they are dependent on nutrients in animal flesh for survival, and because of the large proportion of meat in their diet they are sometimes referred to as hypercarnivores. Of the 13 terrestrial families in the order Carnivora, they are the strictest carnivores. The Felidae comprises two subfamilies, the Pantherinae and the Felinae. The former includes the "Panthera" species tiger, lion, jaguar, leopard, snow leopard, and "Neofelis" species clouded leopard and Sunda clouded leopard. All the non-pantherine cats are part of the Felinae, which includes several genera and the majority of cat species. The first cats emerged during the
People for the Ethical Treatment of Animals They promote alternatives, including embryonic stem cell research and in vitro cell research. PETA employees have themselves volunteered for human testing of vaccines; Scott Van Valkenburg, the group's Director of Major Gifts, said in 1999 that he had volunteered for human testing of HIV vaccines. PETA opposes the use of animals for producing clothing made with fur, leather, wool, or silk. It also opposes the use of down from birds and the use of silk from silkworms or spiders. The group notes on its website: "Every year, millions of animals are killed for the clothing industry—all in the name of