this will probably sound stupid, but from my understanding of genetics, you inherit your parents genes, which mix together and form a new dna code which descibes you. Through this process you inherit your parents attributes. Now in order for evolution to "jump" you get genetic mutations. From darwinism the successful genetic mutations live on and reproduce and pass the successful mutation onto their children. Unsucessful ones are lost because the owners die. This is for physical/athletic mutations. Now with mental ones no-one can say whether its right or wrong. homosexuals, last time i checked, cant naturally reproduce with each other, so the mutation cannot be passed on. Therefore you cannot inherit homosexuality from your parents unless it is a ressesive gene, assuming that a homosexual doesnt reproduce with a hetrosexual. If it is recessive, and both your parents are carriers you have a 1 in 4 chance of it becoming dominant (ie, both genes being the same). From this, if it is a genetic trait, then it is a very popular mutation as it cannot be passed down.
Btw, you want me to respect a hatred against another human being? you can dislike people and I can respect that, but when you want to pass laws based on them it is a hatred, dislike sugests you are willing to tolerate it. Also you want me to respect your view that religeon "owns" marriage, even tho it predates your faith. In a court of law, proving prior use invalidates copyrights, this law is based on logical reasoning to prevent mis use. If you were a racist, would you expect me to respect your hatred of black people? I can respect other beliefs but not their hatreds. To me a hatred is not a belief, its a state of mind, you may have reached this state of mind through belief, but that doesnt make it into a belief itself. eg, i believe that homophobics are wrong, however it doesnt make me dislike them as people are more then on belief.
More wars have been started by people stating that their hatred of another is a belief, therefore its ok and should be tolerated. Then stated that everyone in their society shares their belief and therefore has hatred towards others. Then because every1 who is on their side hates the others they become the rightous and should go and remove the others. If it goes wrong, they hide behind their society and throw their hands up, saying it wasnt me personnaly, it was my societys beliefs. eg. Hitler hated the jews, he made the belief that the jews caused the germans to loose ww1. He got a few people to believe this with him, then went and started killing jews on behalf of germany.
here, people hate homosexuals, they make the belief that marriage should exclude homosexuals as marriage is their private club, they go and lobby goverments to make it illegalm when some1 complains they hide behind their religeon saying it was their religeons doing, and that many people cant be wrong.