Why is homosexuality considered wrong?

This objection is commonly raised in support of homosexuality. Of course, what is normal is rarely ever defined but instead, is bantered about and offered as a reason for justifying homosexual activity.

First of all, "normal" is defined as . . .

• dictionary.reference.com
  • "conforming to the standard or the common type; usual; not abnormal; regular; natural."
  • "approximately average in any psychological trait, as intelligence, personality, or emotional adjustment." b. free from any mental disorder; sane.
• thefreedictionary.com
  • "Conforming with, adhering to, or constituting a norm, standard, pattern, level, or type; typical"
  • "Functioning or occurring in a natural way; lacking observable abnormalities or deficiencies."
  • the usual, average, or typical state, degree, form
• websters-onlinline-dictionary.org
  • "Conforming with or constituting a norm or standard or level or type or social norm; not abnormal"
  • "Being approximately average or within certain limits in e.g., intelligence and development; "a perfectly normal child."
  • "Something regarded as a normative example"

Statistical Normality

We can see from the definitions above that homosexuality does not fit in the norm because it is statistically practiced by less than 5% of the population. (See Statistics on the percentage of the population that are homosexual and lesbian). So, in that sense, homosexuality is not normal.

Biological Normality

If homosexuality is considered normal because it occasionally occurs in the animal kingdom, then this does not support it is normal since it is practised by a small percent of animal populations which is below the norm.

If, however, an appeal is made to the fact that homosexuality occurs within animals regardless of the percentage of the occurrence, then this has problems because it implies that whatever occurs in the animal kingdom is normal for us. Then wouldn't this mean that it is normal to eat your young, to eat other creatures alive, to lie in wait to ambush and kill, sniff other human being's rear ends, eat placentas, barf up food to give to your young, and eat your own faeces? But, since people will differentiate between a sexual conduct and eat poop, they apply the it-is-done-in-the-animal-kingdom standard of morality to themselves in a selective fashion--particularly when it centres around their fleshly desires.

Evolution

What about it being normal regarding evolutionary theory? If evolution is how humankind got here, then how did the tendency for homosexuality survive genetically since it does not produce offspring? It would seem that what is normal, evolutionarily speaking, would be that which produces offspring--not that which does not. After all, haven't we evolved over millions of years and billions of generations of biological life forms such that genes that produce survivability are removed from the population? So, from this perspective how could homosexuality be considered normal? In fact, evolutionarily speaking, homosexuality would be abnormal; and it would have to be a learned behaviour.

So, whenever anyone says that homosexuality is normal, it becomes obvious that the standard of normality either doesn't exist or when they try to cite one that it works against them. Is homosexuality a normal practice? I certainly don't see how it could be.