Yes, but genes that prevent procreation are usually eliminated by evolution.
You missed my point. A person could carry a gene without a phenotypic expression of that gene. So a person could carry a 'gay gene' while still being straight and procreating. Thus the gene doesn't necessarily prevent procreation.
IN FACT, one theory posited is that the same gene(s) that contribute to homosexuality in men actually help women (who carry the gene(s)) produce more children. Whether this is true or not is another story. The point is, even if homosexuals never had children this theory shows how such genes could nevertheless spread.
20th century French philosophers. Le sigh. The term '
heterosexuality' was created in the 19th century thus I can only assume that heterosexuality did not exist prior to the 19th century. Sure, the homosexual
lifestyle is a modern cultural creation. However homosexuality is not.