You think. Why do you think this? Your "obvious" evolutionary reasons don't really line up with the rest of nature.
What part of reality do you not see them lining up with? Incidences of men marrying multiple women is far higher than the other way around.
Exactly as you would expect from evolution.
I never actually said that. I was giving an example about out how incestuous couples harm society. That is all. Don't try to extend the meaning beyond that, because that was it.
You were giving an example how having children out of wedlock is bad. This does not argue against incestuous marriage unless you see procreation and marriage as tied together.
So by your logic, anyone who is infertile should be denied the same privileges as homosexuals? Ability to procreate isn't a requirement for heterosexual marriage, so why is it for homosexuals? You're leaving this door wide open for people to shoot holes in.
Do you have a foolproof test to determine fertility? Are you in favor of the government violating people's medical privacy?
The "hole" you pretend to see has been addressed in Court:
With respect to the claim of an equal-protection violation, the Court found that childless marriages presented no more than a theoretical imperfection in the state's rationale for limiting marriage to different-sex couples. It found the plaintiffs' reliance on the U.S. Supreme Court's recent decision in Loving v. Virginia, finding an anti-miscegenation law, failed to provide a parallel: "in commonsense and in a constitutional sense, there is a clear distinction between a marital restriction based merely upon race and one based upon the fundamental difference in sex.
http://en.wikipedia.org/wiki/Baker_v._Nelson#Appeal_to_the_Minnesota_Supreme_Court
Also, preventing children out-of-wedlock would occur so long as it least one person in the heterosexual couple is fertile. This is an important societal goal in and of itself.
And as was pointed out by the courts it is a purely theoretical problem. Go back 100 years and you will see how silly your argument is. Essentially the problem of childless heterosexual is a modern creation and no one has gone to "fix" the problem. And putting limitations on marriage is likely a lot harder than expanding it. And at the same time while childless couples do not fit the deep philosophical definition of marriage, they do fit the colloquial definition of it as being between a man and a woman.
Why is it that Canada, the UK, France, Belgium, Denmark, Iceland, Holland, Norway, New Zealand, Portugal, South Africa, Spain, Sweden, Argentina, Brazil, NY, RI, CT, DC, IA, MA, MD, ME, NH, VT, WA and others do support it?
Are you suggesting that India, Japan, and China are more Christian than the places you list?
See especially
http://en.wikipedia.org/wiki/Brazil#Religion
China's a whole other ball game. Unless you want to dig up the entire culture that surrounds marriage and the restrictions therein, let's just not go there. India has an extremely homophobic culture. Japan has had a longstanding history of homosexual activities. Read up on samurai and kagema. There just isn't enough political drive today to change their present laws.
Does Japan support same-sex marriage? No. And that was the question.
Also, interesting that you point out that India has an "extremely homophobic culture" since you assertion was apparently that such a culture should be tied to the bible...
One of the loudest arguments against SSM in the States is because of "God". The Church has had an incredibly strong impact on the formation of many western cultures. The States is just the one where it's still the most prevalent in law.
And all of the "loudest" arguments for SSM also support human-dog marriage. Which has been my point.
Also, there are 2 possibilities.
(1) Assume the bible is essentially true. In this case the bible is the word of God and we should be following it.
(2) The bible is false and God does not exist. In this case the bible is nothing more than the word of man and actually reflects the cultural traditions of man and religion is merely a reflection of that.
Neither possibility really supports your side. Either they are trying to force the values of an actual real deity on society. Or they are just trying to force their values on society the same as you.