Correct, there is little evidence of the effect homosexual unions have on developing children, because the unions are an anomaly.
Yet, on the contrary, study after study has come to the conclusion that children do best being raised in a home where their biological mother and father are married to each other. Children raised in such a home are less likely to kill themselves, drop out of school, abuse alcohol and drugs, be promiscuous or participate in illegal activities.
We know what works! Monogamous marriage between a man and a woman produces better citizens. This should be encouraged, not made a mockery of.
Kids are not experiments. I don't think it is fair to force them to participate in social experimentation!
Homosexuals are not able to reproduce, since it takes both sexes to do so. It is not fair for children to be placed in a home with two same sex sexual partners, in a political attempt to engineer social change in our society.
If the so-called homosexual already has children, then I guess the argument that their "oreintation" is "normal for them"; and "inborn"; does not apply, as they were able to have natural sex....
I think you are mixing up the issue of gay adoption with gay marriage. As to the former, yes, all things being equal, I think preference should be given to a married heterosexual couple. But all things are rarely equal. I don't think there is much evidence that children of gay parents are at all that much of a disadvantage. I suspect most of angst about gay parents is just a reflection of a distaste for gays in general. If you have hard evidence from a reliable source, feel free to post it.