Carbon Chauvinism
Carbon chauvinism is a relatively new term meant to disparage the assumption that extraterrestrial life will resemble life on Earth. The term was used as early as 1973, when Carl Sagan described it and other human chauvinisms that limit imagination of possible extraterrestrial life.
Scientist 1: "All forms of terrestrial life must be carbon-based."
Scientist 2: "Dude, that's carbon chauvinism...silicone is a possible building block of life. Just look at breast implants."
Scientist 2: "Dude, that's carbon chauvinism...silicone is a possible building block of life. Just look at breast implants."