The underlying message is that we as a society should just accept any and all manifestations of sexual orientation and sexual behavior because people are merely acting upon their God-given biological inclinations. The end result for those saturated in this cultural marinade is that they are afraid to refuse the designation of marriage to same-sex couples who are only doing what comes "naturally" to them.

There are two problems with this type of reasoning. First, it's questionable whether sexual orientation is biologically determined. Second, even if genetic and developmental factors cause one to have same-sex attractions, it does not follow that one's biology should determine one's behavior, much less dictate one's morality.

In the last twenty years, scientific research has failed to generate a consensus on the exact relationship between biological factors and same-sex attractions. But there is general agreement that genetic/developmental factors do have an influence.

In fact, there is good evidence that genetic and/or developmental alterations can lead to homosexual behaviors in animals ranging from fruit flies to rams. Genetic manipulations in fruit flies, for example, have produced female flies that display courtship to other females and males that display courtship to other males. Similar results have been found in mice, with one recent studyshowing that removing a single gene in females causes them to attempt to copulate with other females and to exhibit other male-specific behaviors.

Studies with rams have found that changes in pre-natal exposure totestosterone can cause structural changes in specific sexually dimorphic brain regions, changes that have been linked to homosexual behaviors.

While it seems clear that some animals can be "born this way," things are much more ambiguous in humans. For starters, human sexual inclinations are much more complex and nuanced, as evidenced by the broad continuum of human sexual orientations and behaviors. Because of this, social scientists lack a clear consensus on what exactly it means to be gay, bisexual, or lesbian. Not only is sexual orientation in humans difficult to pin down-should anyone who has homosexual thoughts be considered gay-it is notoriously fluid, as an individual's identification as gay, bisexual, or heterosexual often changes repeatedly over time. Both of these points are argued persuasively by psychiatrist Paul McHugh in his amicus brief to the Supreme Court in the Hollingsworth case.

Given these complexities, it should not be surprising that studies looking for a biological cause for homosexuality in humans have been equivocal, leaving plenty of room for social and environmental factors to influence sexual preference.

For example, no gene has yet been definitively linked to homosexuality. While some studies have found genes or chromosome regions that may be linked, follow up studies have reported contradictory results.

There is stronger evidence that developmental factors can influence homosexual behavior, but even here there are caveats. Women who have congenital adrenal hyperplasia (CAH) are exposed to higher levels of male sex hormones in utero and have a higher propensity to exhibit homosexual behavior as adults. Still, the majority of these women are heterosexual and only a small minority of CAH females is exclusively homosexual, indicating that other factors, most likely social ones, are at work.

Likewise, there is evidence that having an older brother increases the likelihood of homosexuality in boys. Researchers hypothesize that the mother produces an immune response to male-specific antigens in the first pregnancy, a response that can disrupt normal development in later male pregnancies. Again though, most men with an older brother are heterosexual and many homosexual men have no older brothers, so this hypothesis is limited in scope.

Consequently, it's not clear whether all people with homosexual inclinations, or even the majority, are born that way or if social and environmental factors shape their attractions. But even if one were to grant, in the face of ambiguous evidence, that Lady Gaga is right, it doesn't follow that such behavior should be promoted and sanctioned by codifying same-sex marriage into law.

We are not at the mercy of our biology. This is what sets humans apart from the other animals. In a recent op-ed in the New York Times, titled "Nature's Case for Same Sex Marriage," biologist David Haskell claims that homosexuality is natural in the trivial sense that homosexual activity occurs in nature. Yet, after highlighting the homosexual behavior of pygmy chimps and mallard ducks in an attempt to soften the resistance to same-sex marriage, Haskell had the good sense to realize that animal behavior "does not provide [us] ready-made moral guidance." He could have made this even clearer by discussing the fact that chimps and orangutans satisfy their biological urge for reproductive dominance via rape and/or infanticide.

As primates, our sexual behavior is certainly influenced by our biology (this is true regardless of our sexual orientation). Yet the mere fact that we have a biological urge or tendency does not give us justification to act on it.

In fact, the legal and social framework of civil society is structured by the premise that we should keep our biologically-driven desires in check or channel them for the sake of the common good. For example, males have a biological tendency-it's in our genetic make-up-to find pornography titillating. That doesn't mean that our society should promote it or encourage its use. Evidence suggests that pornography use hurts our ability to form the stable committed relationships necessary to a productive, well-ordered society. Thus society has laws (though they are ever being eroded) that limit and restrict where pornography can be displayed and who can view it.

Likewise, the unfettered expression of the male sex drive, particularly by men who claim to have a biologically heightened appetite (addiction) to sex, is hardly beneficial to society. Just ask any kid growing up fatherless or any single mother abandoned by her child's father. To prevent or mitigate these effects, our society has laws to counter these natural biological urges, laws against adultery, even though they are no longer enforced, and laws that require child support and alimony payments.

Clearly, having a biological predisposition or urge does not justify pursuing it, let alone justify promoting it as a society. The same holds true for same-sex marriage. Even if we eventually decipher a clear biological explanation for homosexual inclinations, we need to have a respectful debate about whether promoting and encouraging people to act on them benefits society as a whole.

In the case of same-sex marriage, there is an acute need for both open discussion and clear investigation of how promoting homosexual inclinations would influence the family, especially parenting. Unfortunately, most Americans avoid this kind of debate, because they have swallowed laissez-faire libertarianism and biological determinism, and because LGBT activists actively prevent the debate from unfolding.

Daniel Kuebler is Professor of Biology at Franciscan University of Steubenville. This article has been republished from MercatorNet's partner site Public Discourse

See more at: http://www.mercatornet.com/articles/view/memo_to_lady_gaga_born_this_way_doesnt_mean_act_this_way#sthash.7dq1qT1I.dpuf