"Our legal and moral systems are deeply species-bound. The director of a zoo is legally entitled to 'put down' a chimpanzee that is surplus to requirements, while any suggestions that he might 'put down' a redundant keeper or ticket-seller would be greeted with howls of incredulous outrage.
The chimpanzee is the property of the zoo. Humans are nowadays not supposed to be anybody's property, yet the rationale for discriminating against a chimpanzee in this way is seldom spelled out, and I doubt if there is a defensible rationale at all.
Such is the breathtaking speciesism of our Christian-inspired attitude, the abortion of a single human zygote (most of them are destined to be spontaneously aborted anyway) can arouse more moral solicitude and righteous indignation than the vivisection of any number of intelligent adult chimpanzees! [...] The only reason we can be comfortable with such a double standard is that the intermediates between humans and chimps are all dead."

"Nearly all peoples have developed their own creation myth, and the Genesis story is just the one that happened to have been adopted by one particular tribe of Middle Eastern herders. It has no more special status than the belief of a particular West African tribe that the world was created from the excrement of ants. All these myths have in common that they depend upon the deliberate intentions of some kind of supernatural being."

Richard Dawkins,
The Blind Watchmaker (1986), Chapters 10+11