Is homosexuality a normal condition of human beings? yes or no.
Now that depends on what you mean by "normal."
If by normal you mean that the majority of people are that way, no. If by normal you mean fully functional in life then yes. Sure, there are gays who aren't, but not because they are gay. There are straights who aren't as well
biologically normal, mammalian normal, homo sapiens normal, historically normal. Its not a hard question.
You're talking to a math major, Six Sigma Blackbelt, MBA. No question is simple to me.
Sure gays don't perpetuate the species, but they are a small percent, they are no threat to perpetuating the species. My brother and I have kids, my sister doesn't. She's not threatening the human race either.
People are turned on by all sorts of things, hair color, small butts, big butts, uniforms, umbrellas. It's a bizarre sexual world. I don't see the issue with a turn on being the same sex meaning are not sexually normal any more than anyone who doesn't want kids