The gay gene

The debate whether homosexuality is a personal choice, a biological makeup or a combination of both has been a hot button issue with many individuals, especially in religion. The study going on in this article says that someone by the name of Dean Hamer is doing a study and trying to find a gene that is passed from mother to males in the family that is responsible for having the gay trait.
http://discovermagazine.com/2007/jun/born-gay

In the homeless guy case, where you could kill him in order to save five others, maybe that homeless guy would become a doctor in the future and save many. But if you kill him then, then it wouldn't be as beneficial to society in the long run.

I was looking over Richard Dawkins and Daniel Dennett's comments on religion and science, and they kept bringing up the question of if one should believe faith or science? What do you believe in: something that you have a feeling but have no proof, or do you believe in science which may have hard proof but there is no deep feeling (that feeling of faith)?